Tag: Freshwater Fish Profiles

Oscar fish are one of those species I always hesitate to recommend to new hobbyists — not because they’re difficult to keep, but because people seriously underestimate how large they get and how much waste they produce. I’ve seen too many oscars end up in tanks that are way too small. When you set them up correctly though, they’re one of the most interactive, personality-driven fish you can keep in freshwater. This guide covers all 8 types and what you need to make them thrive.

Oscar fish are one of the most rewarding freshwater fish you can keep — and one of the most commonly mistreated. I’ve seen it countless times: someone buys a cute 3-inch oscar at the store and doesn’t realize it’s going to hit 12 to 14 inches and need at least a 75-gallon tank by itself. Oscars are also genuinely intelligent — they recognize their owners, beg for food, and have distinct personalities. That interactivity is exactly what makes them so popular. But they’re messy, aggressive toward smaller fish, and demand serious filtration. If you go in prepared, they’re incredible. Here are 8 types of oscar worth knowing about.

Introduction to Oscar Fish

Oscar fish are a longtime favorite in the aquarium hobby and one of the most popular freshwater fish period. These fish are big, colorful, and full of personality. So much so that they have been nicknamed the aquarium puppy or river dog by some due to their extremely playful behavior.

Like other popular freshwater fish, the oscar fish has been subjected to improper care by beginner and inexperienced hobbyists. Many first-time oscar owners are not aware of their true size and just how quickly they will outgrow a tank. If given the right care, these fish can fill a larger tank all on their own.

The most popular type of oscar fish is the traditional orange and brown combination of the tiger oscar, but there are many varieties available for the more adventurous hobbyist.

Oscar Fish Care Requirements

Oscar fish are not impulse buys. They require long-term planning in regards to tank size, tank mates, and diet. Unfortunately, these fish are commonly sold as juveniles when they’re only a couple of inches big, tricking unknowing hobbyists about their true care requirements.

The truth is that Oscars are monster fish that not many hobbyists have the ability to care for. However, if you’re willing to give a very large tank to one single fish, then the oscar fish might be the best choice.

Their Natural Habitat

Oscar fish are scientifically known as Astronotus ocellatus. They are a type of cichlid though they’re not as aggressive as some of their closest relatives.

Instead, these gentle giants scour the basin of the Amazon River basin in South America for whatever can fit in their mouths. They have been documented in most countries throughout South America, but have known established populations in the United States as well as Singapore.

These ecosystems are heavily forested with a silt substrate. They prefer slow-moving rivers and tributaries with various structures, like tree limbs, where they can hide and claim territory. Oscars can be found living solitary lives or in small groups.

Tank Requirements

In terms of fishkeeping, oscar fish are just another type of South American fish from blackwater conditions. However, their mature size is what makes them difficult to keep.

Most oscar fish will surpass 1 foot in length at their mature size. In the store, they’re usually sold while they’re still small, which makes more hobbyists willing to buy them; this is a mistake as they’re put into a holding tank that they’ll grow out of with a promised upgrade in the near future. Most times, they’ve never actually given a bigger tank after that and the fish needs to be rehomed.

The bare minimum tank size for any type of oscar fish is 75 gallons. A 125 gallon tank is even better to allow for more swimming space and more controllable water parameters.

This tank should be given a powerful filter to keep up with the messy habits of oscar fish. Additional flow is not needed and lighting can remain dim. They prefer a sandy bottom and will enjoy rummaging through it for additional food to eat; this also means that live plants are not safe from being uprooted!

Otherwise, oscar fish tank setup is simple. Add some rocks and driftwood for shelter and your oscar will thrive.

What Is The Biggest Type?

We mentioned before that oscars are monster fish and can easily surpass a foot at adult size. But how big can they actually get and are the different types of oscar fish different sizes?

The biggest that oscar fish can get to be in captivity is about 18 inches and several pounds. It is rare for them to get any bigger than this, though they can keep growing over their 20 year lifespan.

Most types of tiger oscar that were derived from Astronotus ocellatus have the ability to reach these monstrous sizes. Some breeders have made short-bodied varieties that may stay slightly smaller, though.

Temperament

If oscar fish are known for one thing, it’s their personalities. These fish are full of life and will let you know when they don’t like something in their tank.

It is important to understand that Oscars are not aggressive fish, though most hobbyists refer to them as aggressive. Yes, they will defend their territories and chase after problematic tank mates, but they won’t attack other fish without a reason. Instead, they are labeled as being aggressive due to their appetite which makes them eat almost everything in sight.

Oscars are slow-moving fish. They will usually be seen floating in the water column, occasionally moving around to search for food. That being said, they enjoy having plenty of swimming room for when they get quick bursts of energy.

At the same time, these fish can be quite temperamental. If something is added to the tank that they don’t like, they will become less active and might even try to uproot whatever the new addition is. Even then, they are likely to uproot decorations with no intent.

Lastly, oscar fish love their owners. They will recognize the person that feeds them and may eat directly out of their hand.

Tank Mates

Due to tank size and waste management, most hobbyists don’t keep their oscars with other fish, especially not in a community tank. If space isn’t a problem, then there are a few tank mate options that can go with most types of oscar fish.

The goal is to get a fish that is too large to be eaten. Some hobbyist feel getting small, fast, schooling fish that can escape your oscar in a large tank are worth it. The logic here is that they can be easily replaced. Going with small fast fish is an approach I wouldn’t recommend.

One of the best oscar fish pairings is with the severum cichlid (Heros severus). This is because these fish share similar tank and water conditions. Severums are also big enough to hold their own against a full-grown oscar.

Other possible oscar tank mates include:

• Chocolate/emerald cichlids (Hypselecara temporalis)
• True parrot cichlids (Hoplarchus psittacus)
• Green terror cichlids (Andinoacara rivulatus)
• Flagtail prochilodus (Semaprochilodus insignis)
• Silver dollars (Metynnis spp.)

Diet

Oscars may be the least picky of all eaters; oscar fish eat anything that fits inside their mouths, and we mean anything.

Oscar fish are primarily carnivores, meaning they prefer a diet that consists of meaty foods. From there, the possibilities are nearly endless for food options.

These beautiful fish will enjoy a variety of live, frozen, and freeze-dried foods such as:

• Worms (bloodworms, ,blackworms, earthworms, Tubifex worms)
• Shrimp (full raw shrimp, brine shrimp)
• Mollusks (clams, scallops, mussels)
• Insects (insect larvae, crickets, mealworms)

To help keep costs down, oscar fish may be given high-quality cichlid flakes or pellets; pellets may be preferred as some oscars may refuse to come to the surface to eat. Most local pet stores also carry specific oscar fish food.

These large fish will eat as much food as they’re given, which can lead to water quality issues and a lazy fish if overindulged. Eventually, your fish will greet you at the top of the tank waiting to be fed.

Top 8 Types to Choose From

The most common oscar variety to see is the tiger oscar fish. But did you know there are several other types of oscar fish with incredible colors and patterns?

Some of these include the blue oscar fish, black oscar fish, and veil tail oscar fish. Some of these varieties may be harder to find than others, though they all generally share the same care requirements.

1. Tiger

• Adult Size: 1 foot
• Color Pattern: Orange/red marble on black/brown body
• Unique Traits: Dorsal fin eyespot

The tiger oscar fish, also known as the marble cichlid or the velvet cichlid, is the original variation of Astronotus ocellatus. These fish are very common to find in aquarium stores and can be identified by their red and orange marble patterning on their dark body; they will also have a bright, unique eyespot beneath the dorsal fin near the tail.

There is no difference between male and female oscars at any time besides breeding periods. They can successfully be kept in pairs in the aquarium as long as the tank size is adequate.

2. Albino

• Adult Size: 1 foot
• Color Pattern: Light pink shading on platinum white body
• Unique Traits: Pink/red eyes

Albino oscars are a natural albino variety of the tiger oscar fish, Astronotus ocellatus. As an albino fish, these oscars have a genetic disorder that causes reduced production of melanin. This results in a platinum white fish with possible lighter pink shading and no marbling.

However, there are not many true albino oscar fish available; albinism is relatively rare and these fish are in high demand. Because of this, many oscars that are sold as albino are actually lutino.

At first glance, a lutino oscar fish will look albino. The main difference is that lutino oscar fish have marbled, orange patterning while albino oscar fish can have red or pink shading. When in doubt, check the eye color to distinguish between these two very similar-looking fish!

3. Blue

• Adult Size: 1 foot
• Color Pattern: Contrasting shades of blue with some orange marble patterning
• Unique Traits: Intensity of blue varies between individuals

The blue oscar fish (picture source) is extremely rare to find in the aquarium hobby. This is a selectively bred fish that isn’t widely available, leaving it to be on display in only the best of the best aquariums.

These fish have beautiful, intricate shading where some scales are darker and more intense blue than others. This, paired with the contrast created by the orange marbling, can create a dazzling display unlike any other fish.

While blue oscar fish have been compared to other intensely colored cichlids, like the electric blue acara (Andinoacara pulcher), there is a depth that has yet to be recreated in another species.

4. Black

• Adult Size: 1 foot
• Color Pattern: Dark body with shaded bands
• Unique Traits: Light colored belly

Instead of going vibrant, breeders chose to bring out the best of the dark aspects that oscar fish have to offer. The tiger oscar is a naturally dark fish, but hobbyists took it one step further with the black oscar (video source).

The black oscar fish is largely a selectively bred fish that has been designed to bring out the intensity of the browns, blacks, and greys that these fish have to offer. As a result, the bodies of these oscar fish are a uniform shade of grey with overlaying darker, marbled bands. The stomach is usually lighter and some orange or red patterning may also be present.

It should be noted that some tiger oscar fish are naturally darker than others. A black oscar fish will generally lack the intense marbling that comes with the original variation of this fish.

5. Veil Tail

• Adult Size: 1 foot
• Color Pattern: Orange/red marble on black/brown body (tiger oscar variation)
• Unique Traits: Elongated fins

The veil tail oscar fish (video source) is a very beautified fish. These fish have been bred to express extra-long finnage, much like veil tail betta fish. These extended tails are almost threadlike and carry the signature black and orange color combination from regular tiger Oscars.

Though veil tail oscar fish have regular coloration, their patterns have also been exaggerated. Oranges have been intensified and might appear as more organized lines than random blotches across the side of the fish.

It should be noted that these fins are especially susceptible to being nibbled on by other fish in the tank. Extra-long fins may also become too heavy for your oscar fish to carry, leading them to regularly rest on the substrate and other surfaces around the aquarium.

6. Red

• Adult Size: 1 foot
• Color Pattern: Orange/red body with minimal blacks/greys
• Unique Traits: Fiery red body

The red oscar (video source) is the exact opposite of the black oscar. Instead of the dark colors of the tiger oscar being enhanced, the reds and oranges have been maxed out.

Red oscar fish have almost entirely red-orange bodies; there are no remnants of the regular marbled patterning and the majority of the fish is a fiery color. The only parts that usually remain black or grey are the face and fins.

In general, an oscar fish with a higher degree of red is more desirable than one with less. This is one of the most attainable varieties of oscar fish in the hobby, though quality will vary along with the price.

There are many other types of red oscar, including the chili red oscar fish and albino super red tiger oscar fish. These types will vary in intensity and presence of red; some of the highest quality red varieties will present as a uniform red body.

7. Lemon

• Adult Size: 1 foot
• Color Pattern: Light yellow on creamy white body
• Unique Traits: Yellow coloration

Named for obvious reasons, the lemon oscar fish (video source) can be a bright yellow color! However, most lemon oscars are actually creamy white with some hints of yellow; only the highest quality lemon oscars will be bright yellow. Although this coloring might seem difficult to achieve, their popularity has made them largely available.

Yellow is not a very common color to see in predatory freshwater fish, so a lemon oscar fish can instantly become the center of attention for any display. It can also be easy to confuse the lemon oscar with albino or lutino varieties if yellow coloration is minimal.

8. Lutino

• Adult Size: 1 foot
• Color Pattern: Light orange marbling on platinum white body
• Unique Traits: Orange eyes

Often confused with the albino oscar fish, lutino oscars are not truly albino. Instead, these aquarium fish have a near platinum white body with orange or yellow marbled patterning. This is in contrast to true albino oscar fish that lack patterning entirely.

Another main difference between the albino and lutino oscar fish is eye color. Lutino oscars will have orange or dark red eyes while albino fish will have very light pink eyes. Unfortunately, lutino oscars are often sold as albino fish, which can make identification difficult.

How Many Types Are There?

Thanks to the aquarium hobby, there are many different types of oscar fish readily available to most enthusiasts. Scientifically, there are only two species within the Astronotus genus, including Astronotus ocellatus.

Oscars come in a large selection of colors though there is definitely room to expand. Because they require so much space to breed, their true potential remains to be seen.

Final Thoughts

Oscar fish are very hardy fish. Unfortunately, their massive size and tank mate limitations are often unknown to beginner hobbyists looking to purchase a small fish.

Given the right tank size though, there are several types of oscar fish to choose from, all with very similar care requirements but with very different appearances!

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📘 Want to learn more? This article is part of our complete Freshwater Fish Guide — your ultimate resource for freshwater species, care tips, tank setup, and more.

Swordtails are one of my go-to recommendations for beginner freshwater tanks — they’re hardy, colorful, and the males have that unmistakable sword tail that makes them stand out. I’ve kept them in community setups for years and they’re genuinely low-maintenance when conditions are right. One thing most guides don’t mention: swordtails and platies can hybridize, which means you sometimes end up with unexpected colors and body shapes in the tank. Here’s everything you need to know about keeping them successfully.

Swordtails are one of the classic beginner livebearers — hardy, colorful, and genuinely interesting to watch. The males develop that distinctive elongated lower tail fin that gives the fish its name, and it’s one of those features that looks better in person than in photos. Like platies and guppies, they’re undemanding and adapt well to a range of conditions, which makes them great for community setups. One thing worth knowing: swordtails and platies are closely related and can actually interbreed, so if you keep both you may end up with hybrids. Males can also be aggressive toward each other, so a ratio of one male to two or three females keeps the peace. Here’s everything you need to keep them well.

A Brief Overview Of The Swordtail Fish

Scientific Name	Xiphophorus hellerii
Common Names	Specific names depend on coloration; widely referred to as swordtail fish
Family	Poeciliidae
Origin	North America and Central America
Diet	Omnivore
Care Level	Easy
Activity	Peaceful
Lifespan	3 – 5 years
Temperament	Peaceful
Tank Level	All levels
Minimum Tank Size	20 gallons
Temperature Range	64 ° to 82 °F
Water Hardness	1 – 12 dKH
pH Range	7.0 – 8.2
Filtration/Water Flow	Moderate to high
Water Type	Freshwater
Breeding	Livebearer
Difficulty to Breed	Easy
Compatibility	Community tanks
OK, for Planted Tanks?	Yes

Swordtail Fish Origins and Habitat

Swordtails are one of the most easily recognizable freshwater fish in the entire aquarium hobby. The swordtail fish have been bred to display all colors and pattern variations while still maintaining their status as being one of the easiest species to keep in the freshwater aquarium. These aquarium fish didn’t start out like this, though.

Instead, swordtails originate from North and Central America, specifically from Veracruz in Mexico to northwestern Honduras. There, they are found in a variety of ecosystems with varying altitudes, turbidities, depths, water flows, and even salinities. Most often, they are found in relatively shallow systems with dense vegetation. Adults are likely to be in areas of high flow while juveniles will stick towards the margins where conditions are calmer.

Unfortunately, swordtail fish have entered the waterways of many nonnative continents and countries. They are largely found throughout portions of South America, Africa, and Australia where their invasive populations harm native species¹. Most of these populations have been established through aquarium releases.

Originally, these freshwater species were known as green swordtail fish due to their natural green bodies and red accents. Through the years, these swordtail fish were very carefully bred for color and pattern combinations which eventually led to the overwhelming array of choices available today.

As we’ll see though, colors aren’t the only thing that has changed about the swordtail fish.

For some hobbyists, this can be a problem.

Swordtails, like other livebearing species, are prolific breeders. Anytime there is a male and female swordtail fish present in the tank, there are likely to be baby swordtails. Adding a swordtail to an aquarium can potentially limit hobbyists in their future livestock additions due to reproduction rates and overstocking.

What Do They Look Like?

Swordtails are very recognizable due to their famous feature: their tail that resembles a sword!

On average, swordtail fish grow to be about 5 inches, though they can measure up to 6 inches and can become quite plump. They have a wide, torpedo-shaped body and round stomach. They are unique in that their dorsal fin is higher than other tropical freshwater fish and the bottom ray of their caudal fin extends well past the rest of their tail.

This extension makes sexing swordtail fish easy. Males have this feature while females do not; females have a rounded caudal fin with no other special markings and resemble a platyfish (Xiphophorus maculatus). Males are also typically more colorful and smaller than their female counterparts.

The most common color for swordtails to come in is red; the whole body will be red with a noticeable darker mid-lateral line, especially on the males. The fin extension may also be a different color from the rest of the body or have different colored margins depending on the variety of fish.

Swordtail Varieties

Once originally known as the green swordtail, beautiful though plain in color, these aquarium fish have been selectively bred to display almost every color and every pattern combination, mostly consisting of reds, yellows, and oranges.

It should be noted that swordtails have successfully been hybridized with other species within the Xiphophorus genus, making the possibilities endless.

Here are some of the most common colors to come across as well as the most designer swordtail varieties available:

Red swordtail. The red swordtail fish is the most common variation to come across. Both males and females are uniform in color, though males may have a black margin to their tail fin extension.

Red wag swordtail. The red wag swordtail is a normal swordtail but with black fins. All other features and requirements are the same as the regular red swordtail.

Pineapple swordtail. The swordtail fish with the best name, these swordtails have a red back with a pale yellow body and white belly. They may have slightly shorter fin extensions than other varieties, which can be a favorable combination along with their colors.

Red lyretail swordtail. These swordtail fish are named after the instrument as both males and females have a u-shaped tail fin. The body is light orange/red while the dorsal and tail fins are usually black.

Hi fin lyretail swordtail. An even more accentuated version of the red lyretail swordtail, the hi fin attribute comes from the extremely elongated dorsal fin which is almost as long as their tails; females do not have such exaggerated features. Colors include red, orange, and yellow. Because of their extreme features, hi fin lyretail swordtails need at least a 30-gallon tank and very carefully chosen tank mates that won’t nip at fins.

Are They A Type Of Molly Fish?

Mollies, platies, swordtails. They all kind of look the same and have similar care requirements, but what makes them different?

Swordtails are not a type of molly or platy, even though they are all closely related. Looking at the scientific categorization of these freshwater species, swordtails are Xiphophorus hellerii, mollies are Poecilia latipinna, and platies are Xiphophorus maculatus.

As we can see, mollies are in a different scientific genus altogether. However, swordtails are in the same genus, Xiphophorus, as platies and are very closely related. Though there are slight variations between these two species–namely, the absence of the elongated tail fin in platies–there is a larger difference in geographic distribution.

The Xiphophorus genus is split into three phylogeographic clades based on origin. Platies are native to eastern Mexico and Central America. Northern swordtails are found in very specific regions of northeastern Mexico. Southern swordtails, like the ones listed in this article, originate from southern Mexico and northern Central America.

Care – Temperament and Activity Level

Swordtail fish are a favorite among beginner hobbyists due to their flashy and active behavior. These fish will quickly fill up empty space in the upper and middle portions of the tank, only venturing to the bottom for food.

While great additions to the community tank, swordtails can be slightly aggressive towards each other, specifically from male to male. As we’ll see, it’s recommended to keep a very high male-to-female ratio to keep males from becoming aggressive to one another. Males may also become aggressive to similar-looking fish of other species.

Otherwise, these active fish will provide constant movement to the aquarium display. When they’re not looking for food to pick off of plants and decorations, they’ll be looking to mate.

What Are Good Tank Mates for Swordtails?

Swordtails are compatible with most freshwater fish. They are big enough to tolerate larger, slightly more aggressive species while bringing out the best in smaller, schooling types.

The most important thing to consider when choosing swordtail fish tank mates is fin nipping. These fish have beautiful fins that you don’t want to see get shredded or infected with fin rot!

Here are some of the best tank mates for swordtails:

• Platies
• Mollies
• Guppies
• Corydoras
• Angelfish
• Gouramis
• Tetras
• Danios
• Barbs

Remember that swordtail fish are capable of hybridizing with platies. While this isn’t necessarily wrong to allow happen, hybridization can lead to some genetic mutations and loss of color lineages.

It should also be noted that keeping swordtails with other prolific livebearers, like platies or guppies, can quickly lead to overpopulation if not controlled.

How Many Swordtails Should Be Kept Together?

Contrary to popular belief, swordtail fish are not a schooling species. They like to be in group settings but won’t actively follow around the other swordtails in the tank for protection.

That being said, swordtail fish do best when kept in groups of 4 to 6. At least two or three females should be kept for every one male. Hobbyists have had success keeping only one male swordtail fish in a tank–which is the preferred setting if wanting to avoid any chances of reproduction–but they will thrive in a social community setting.

Since male and female fish are so easy to tell apart, it is recommended to skip a male addition altogether. However, keep in mind that there is the chance for females to already be pregnant before adding them to your tank.

Can Bettas and Swordtails Live Together?

Another great beginner fish is the Betta (Betta splendens). These fish are nowhere near as active as the swordtail fish but males are especially colorful with bold personalities. So much so that betta fish are notorious fighting fish that could easily injure a swordtail if paired together.

Because of this, bettas should not be attempted to live with swordtails. These two fish are not compatible tank mates as swordtails are overly active and can become fin nippers. This could stress out your betta and lead to infection.

What Do They Eat?

Swordtail fish are omnivores and will gladly eat whatever they are given. They will love foraging for food on live plants and other decorations, but will readily accept an assortment of live, frozen, and freeze-dried foods, like bloodworms, brine shrimp, and mosquito larvae.

To maintain their color, a high-quality tropical fish flake food or pellet should be offered daily; quality flake food is slightly more preferred as they stay at the water’s surface longer. Swordtail fish may also be given algae pellets or flakes as well as blanched vegetables from time to time.

What Plants Do They Eat?

While foraging for food on live plants, swordtail fish have been known to accidentally–or purposely–eat some leaves.

Swordtails are great algae eaters and will help keep plants free from pests. However, they are so efficient that they might not be able to tell algae apart from a desired live plant. This behavior can be deterred by feeding more often or adding less desired plants that are meant to be eaten.

Setting Up Your Tank

Swordtails are very hardy fish and can live in a variety of aquarium setups. Like any fish, swordtail fish need to be kept in a fully cycled aquarium with stable water parameters. Swordtail fish can be slightly messier than other freshwater fish so it’s important that the mechanical and biological filtration systems are ready to handle the bioload.

Swordtail fish look especially great in a densely planted aquarium on a dark substrate. They will need an aquarium hood to prevent them from jumping out.

Tank Size

Swordtail fish are one of the more demanding beginner species when it comes to tank size. These fish are relatively big, active, and need to be kept in small groups. They can also create a lot of bioload for so few fish.

To help bolster the biological filtration system and to give your swordtail fish enough space to swim, a 20 gallon long tank is recommended. A long tank will give much more space for your fish to swim than a tall tank. Even bigger tanks will allow for a much larger selection of fish to choose from.

Filtration

To keep up with bioload, the filter should be rated for at least 2x the size of the aquarium. In regards to swordtail fish, it’s pretty difficult to give too much filtration.

If you remember, these fish live in areas of high flow in their natural habitat. Though most swordtails in the aquarium hobby have adapted to living in community tanks with minimal flow, swordtail fish can surely survive a tank set up with a high water current.

This water flow can be created with filters, powerheads, and wavemakers. Just remember that other community fish might not be able to handle such high water currents as well as your swordtail fish.

Water Parameters

Swordtail fish are very forgiving of incorrect water parameters, but that doesn’t mean that you shouldn’t strive to give them the best. Like any other fish, swordtails will succumb to sudden fluctuations in water parameters.

Swordtails can be kept in a cooler water temperature, though stability is key. A changing water temperature can quickly cause fish to go into shock, so a heater for temperature regulation is strongly recommended. It is also advised to keep swordtail fish in tropical water temperatures in order to have the most choices when it comes to possible tank mates.

Otherwise, swordtail fish need a neutral pH level with limited nitrates.

Breeding

Breeding swordtail fish is straightforward and usually a matter of when rather than if. Swordtails are livebearing fish which means that they will give birth to live young.

First, get a good mix of female and male swordtails. Some hobbyists choose to remove their mating pairs from the main tank display into a specific breeding tank, though this isn’t entirely necessary.

Once ready, males will chase after females and the two fish will mate. Over the next few weeks, the female will grow plumper in appearance until she’s ready to give birth. When she’s ready, she will birth anywhere from 50-200 live fry. Not to mention that females can give birth once every month or so!

The fry will be immediately independent and susceptible to being eaten by the parents and other fish; this usually isn’t a concern as the brood is so large and reproduction can happen so often.

To increase the chances of fry surviving, they should be placed in their own tank or given plenty of coverage in the form of live plants. Small foods, like baby brine shrimp, will need to be offered until they are ready to accept larger foods.

Final Thoughts

Swordtail fish are a popular addition to beginner hobbyist’s fish tanks. These swordtail fish are big, active, and easy to care for but do require some special attention when it comes to water flow and keeping males together.

Otherwise, these peaceful fish are fun and easy to breed, allowing hobbyists to make their own designer swordtail varieties along the way!

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📘 Want to learn more? This article is part of our complete Freshwater Fish Guide — your ultimate resource for freshwater species, care tips, tank setup, and more.

Blue freshwater fish are genuinely hard to find — and I say that as someone who’s been searching for them for 25+ years. True blue coloration in freshwater is rare compared to saltwater, so when I see a fish that genuinely delivers on it, I take notice. These are my top picks after years of keeping and observing them in my own tanks, ranked by how reliably they display that blue color in home aquarium conditions.

Blue is genuinely one of the harder colors to find in freshwater fish — it’s more common in saltwater, which is part of what makes a well-chosen blue freshwater species stand out in a tank. After 25 years in both freshwater and reef keeping, I’ve learned that “blue” can mean a lot of things depending on the fish, the lighting, and even the mood of the animal. Some blues are electric and vivid; others are subtle and iridescent. This list covers 15 of the best options across different tank sizes and care levels, so there’s something here whether you’re running a community tank or a species-only setup.

15 Best Blue Freshwater Fish Species

Choosing the right aquarium fish involves some careful thought. It’s really important to know how big they grow, how much space they need, and whether they will be happy in the kind of water you have.

To make choosing the perfect bluefish easier, I’ve included the following important stats for each species:

• Scientific Name
• Difficulty Level
• Adult Size
• Temperament
• Origin
• Minimum Tank Size
• Temperature
• Diet
• pH
• Difficulty to breed
• Planted tank suitability

Now you’re ready to meet some awesome bluefish! Check out our video above from our YouTube Channel. We go over more details in the blog post below. If you like our content, be sure to subscribe. We post new videos every week!

1. Betta fish/ Siamese fighting fish

• Scientific Name: Betta splendens
• Difficulty Level: Moderate
• Adult Size: 2.5 inches
• Minimum Tank Size: 5 gallons
• Temperature: 75-82°F
• pH: 6.5-7.5
• Temperament: Aggressive
• Origin: Southeast Asia
• Diet: Carnivore
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Betta fish are one of the best blue fish for fishkeepers who want to keep a nano aquarium. Of course, not all bettas are blue, so you’ll need to shop around for a specimen that suits your taste. These pretty fish come in a huge variety of different fin shapes, and can be found in solid blue, or combinations of colors that include everything from turquoise to deep blue!

It’s usually best to keep betta fish on their own. Male bettas are very aggressive fish and will fight and kill other male bettas. Female bettas are less aggressive than males but it can still be risky to keep more than one in the same aquarium.

You can keep a betta fish with tank mates in larger tanks. You just have to be careful about what you add as the betta can prey on small inverts and will be nipped by overactive fish.

2. Fancy Guppies

• Scientific Name: Poecilia reticulata
• Difficulty Level: Easy
• Adult Size: 1.5-2.5 inches
• Minimum Tank Size: 10 gallons
• Temperature: 64-82°F
• pH: 7-8.5
• Temperament: Peaceful
• Origin: Northeastern South America
• Diet: Omnivorous
• Difficulty to breed: Easy
• Planted tank suitability: Yes

Guppies are another hugely popular aquarium fish that come in a range of patterns and colors-including blue! These aquarium fish come in many different shades of blue, including sky and royal blue.

Guppies are peaceful community fish that get along great with other fish. The fancy guppy is a very hardy fish that is easy to care for and will thrive in just about any freshwater tank setup with hard water.

3. Blue Gourami

• Scientific Name: Trichopodus trichopterus
• Difficulty Level: Easy
• Adult Size: 5 inches
• Minimum Tank Size: 20 gallons
• Temperature: 75-86°F
• pH: 5.5-8.5
• Temperament: Semi-aggressive
• Origin: Southeast Asia
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The blue gourami is also known as the three spot gourami. This hardy and easy to care for species is great for fishkeepers who want medium-sized blue aquarium fish.

This gourami species comes in a few different breeds, and not all of them are blue. The best options are the wild 3 spotted form, or even better, the opaline form if you want a really great centerpiece fish.

4. German Blue Rams

• Scientific Name: Mikrogeophagus ramirezi
• Difficulty Level: Moderate/advanced
• Adult Size: 1.5 inches
• Minimum Tank Size: 15 gallons
• Temperature: 80-86°F
• pH: 4-7
• Temperament: Peaceful
• Origin: Venezuela, Colombia
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The German blue ram is one of my favorite blue fish species. If you’re looking for amazing color, the ‘electric blue’ breed will really impress you!

These gorgeous little cichlids are super peaceful fish and stay very small, unlike most other South American cichlids. Unfortunately, the German blue ram is not great for beginners because they need perfect water quality to stay healthy.

5. Blue Peacock Cichlid

• Scientific Name: Aulonocara nyassae
• Difficulty Level: Moderate
• Adult Size: 7 inches
• Minimum Tank Size: 55 gallons
• Temperature: 76-82°F
• pH: 7.8-8.6
• Temperament: Semi-aggressive
• Origin: Lake Malawi, Africa
• Diet: Carnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The blue peacock cichlid is an awesome blue fish from Lake Malawi in Africa. Like most other African cichlids, these fish need high pH water to thrive. These fish are classified as semi-aggressive and become pretty aggressive when breeding, a time when they are their most colorful!

It is best to keep the blue peacock cichlid fish in a group of 1 male and 3 or 4 females to prevent fighting. They are not your typical community fish, and the best tank mates for these fish are other peacock cichlids.

6. Blue Zebra Cichlid

• Scientific Name: Maylandia callainos/ Metriaclima callainos
• Difficulty Level: Moderate
• Adult Size: 6 inches
• Minimum Tank Size: 50 gallons
• Temperature: 76-82°F
• pH: 7.8-8.6
• Temperament: Semi-aggressive
• Origin: Lake Malawi, Africa
• Diet: Herbivore
• Difficulty to breed: Moderate
• Planted tank suitability: Possible

The cobalt blue zebra cichlid is an mbuna cichlid. These fish are known for being quite aggressive if not kept with the right tankmates. It is best to keep one male with 3 or 4 females to limit aggression.

These fish are not suitable for most community aquariums, but they can be amazing in mbuna aquariums with other species of African cichlids.

7. Electric Blue Johanni

• Scientific Name: Melanochromis johannii
• Difficulty Level: Moderate
• Adult Size: 4-5 inches
• Minimum Tank Size: 40 gallons
• Temperature: 73-81°F
• pH: 7.6-8.8
• Temperament: Semi-aggressive
• Origin: Lake Malawi, Africa
• Diet: Omnivore
• Difficulty to breed: Moderate
• Planted tank suitability: Possible

The electric blue johanni is a great little African cichlid with vibrant blue colors. It is only the males that are dark blue, however, and the females are a beautiful golden orange color. Some of the best tank mates for mbuna cichlids like electric blue johannis are other mbuna cichlids from lake Malawi.

8. Frontosa

• Scientific Name: Cyphotilapia frontosa
• Difficulty Level: Moderate
• Adult Size: 10-12 inches
• Minimum Tank Size: 75 gallons
• Temperature: 72-82°F
• pH: 8-9
• Temperament: Semi-aggressive
• Origin: Lake Tanganyika, Africa
• Diet: Carnivore
• Difficulty to breed: Moderate
• Planted tank suitability: Possible

The frontosa, or humphead cichlid, is a great species for fish keepers who want a large and dramatic display tank! These fish are not pure blue, but rather silvery blue with bold vertical black bars. Although you could keep a frontosa cichlid in a tank as small as 70 gallons, you’ll really want a 180-gallon tank or larger to keep them in a group.

9. Discus Fish

• Scientific Name: Symphysodon aequifasciata
• Difficulty Level: Moderate
• Adult Size: 8 inches
• Minimum Tank Size: 55 gallons
• Temperature: 79-86°F
• pH: 6.1-7.5
• Temperament: Peaceful
• Origin: Brazil
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Discus fish are one of the most beautiful (and peaceful) cichlids in the hobby. These colorful freshwater fish get their name for their round, disc-shaped bodies.

There are many varieties of discus available, including some amazing blue types like the cobalt, blue snakeskin, and blue diamond discus.

10. Cardinal Tetra

• Scientific Name: Paracheirodon axelrodi
• Difficulty Level: Moderate
• Adult Size: 1.5 inches
• Minimum Tank Size: 15 gallons
• Temperature: 73-81°F
• pH: 5.5-7.5
• Temperament: Peaceful
• Origin: Brazil and Venezuela
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Cardinal tetras are gorgeous fish that have vivid blue stripes that run the length of their bodies from their bright blue eyes almost to the start of their caudal fin. Cardinal tetras look very similar to our next species, the neon tetra, but have more contrast between red and blue.

These peaceful community fish get along great with other smaller fish. They are ideal for a community setup, especially if kept in schools of 8 or more.

11. Neon Tetra

• Scientific Name: Paracheirodon innesi
• Difficulty Level: Easy
• Adult Size: 1.25 inch
• Minimum Tank Size: 15 gallons
• Temperature: 70-77°F
• pH: 5-7
• Temperament: Peaceful
• Origin: Brazil, Colombia, Peru
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Neon tetras are amazing blue schooling fish with bright blue stripes along their sides. These colorful freshwater fish are similar to cardinal tetras but slightly smaller and do not have as much red color.

Neon tetras are very peaceful fish that get along great with other peaceful tank mates. Like other tetras, these fish should be kept in groups of 8 or more to see them school and behave confidently.

12. Blue Glofish

• Scientific Name: Various
• Difficulty Level: Easy-moderate
• Adult Size: 2 inches for danios and tetras, 6 inches for sharks
• Minimum Tank Size: 15 gallons for danios and tetras, 55 gallons for sharks
• Temperature: 70-75°F
• pH: 7-8
• Temperament: Peaceful/ semi-aggressive
• Origin: Tank bred
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Glofish are some of the most colorful freshwater fish in the aquarium hobby. These fish are genetically modified to show the most amazing vivid color. The cosmic blue tetras, (also available in the longfin variety), cosmic blue danios, and cosmic blue sharks are awesome blue fish for freshwater aquariums.

The tetras and danios are very peaceful schooling fish for an awesome freshwater community tank. They grow to just 2 inches or so in length and should be kept in schools of 6 or more. The cosmic blue sharks are larger fish that are classified as semi-aggressive.

13. Praecox Rainbowfish (Dwarf Neon Rainbowfish)

• Scientific Name: Melanotaenia praecox
• Difficulty Level: Easy
• Adult Size: 3 inches
• Minimum Tank Size: 15 gallons
• Temperature: 73-82°F
• pH: 6.8-7.5
• Temperament: Peaceful
• Origin: Indonesia
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The praecox rainbowfish is a beautiful blue fish with red fins and a red tail. This colorful fish is also known as the dwarf neon rainbowfish because it maxes out at just 3 inches or so and glows with color in the right lighting.

Praecox rainbowfish are active fish that do great in an aquarium community with other shoaling fish. They are great-looking fish to add as a school in medium to large-sized aquariums.

14. Electric Blue Crayfish

• Scientific Name: Procambarus alleni
• Difficulty Level: Easy
• Adult Size: 4-6 inches
• Minimum Tank Size: 30 gallons
• Temperature: 65-70°F
• pH: 6.5-7.5
• Temperament: Semi-aggressive
• Origin: Southeastern United States
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: No

If you’re looking for something a little different for your blue fish aquarium, look no further than the electric blue crayfish (video source)! These awesome critters are native to the United States and they thrive in fish tanks.

Electric blue crayfish are opportunistic feeders that do occasionally catch slow-moving fish. They also love to eat aquarium plants, so they are not ideal for planted tanks. Fast tankmates are recommended, thought not guaranteed that they will not eaten.

15. Freshwater Shrimp

• Scientific Name: Neocaridina davidi, Caridina cantonensis, Caridina serrata
• Difficulty Level: Easy/moderate
• Adult Size: 0.75-1.5 inches
• Minimum Tank Size: 5 gallons
• Temperature: 72-82°F
• pH: 7-8
• Temperament: Peaceful
• Origin: Southeast Asia
• Diet: Omnivorous
• Difficulty to breed: Easy
• Planted tank suitability: Yes

There are many amazing blue shrimps available in the aquarium hobby. Some great examples include the blue velvet shrimp/ blue dream shrimp (Neocaridina davidi), the blue bolt shrimp (Caridina cantonensis), and the aura blue shrimp (Caridina serrata).

Adult shrimp can be kept with some small community fish, but larger fish will probably see your shrimp as a tasty snack! the great thing about shrimp is that you can keep them in a tank of just 5 gallons or so, making them a perfect choice when you don’t have a lot of room.

Bonus for Freshwater Aquariums

Just in case you’re curious about even more blue fish for freshwater aquariums, here are a few more beautiful fish species to check out!

• Electric blue acara
• Electric blue hap cichlid
• Jewel cichlid
• Blue Jack Dempsey fish
• Green terror cichlids
• Powder blue gourami/ blue dwarf gourami
• Paradise fish

Aquarium Fish Care – The Basics

If you’re new to fish keeping, there are some very important things to know before bringing your new blue fish home. Different fish species have different care needs, but the following tips are a good starting point.

Tank Setup

Setting up a great tank is the first step, and this should always be done before you bring your fish home! In fact, you should set up your tank at least a few weeks before introducing any fish to get it fully cycled and ready.

Read on for a basic list of what you’ll need!

Essential equipment

The most important items you’ll need to set up a great freshwater aquarium for blue fish are:

• Fish tank with a hood/cover- Match the size of the tank to the minimum tank size of the fish you want to keep. Bigger is always better, so go a little larger if you can.
• Filter- A filter is extremely important for keeping your water clean and healthy. Choose a filter that is rated for your tank size or larger.
• Aquarium light- Good lighting will make your fish look really amazing. Set your lights on a timer so that they fire up and switch off at the same time every day. This will give your pets a natural day/night rhythm.
• Heater- Tropical fish need a heater to keep the water temperature stable in their preferred range. Choose a model that matches your tank size.
• Thermometer

These are the basic components of a tropical fish tank. While it is possible to set up a fish tank with just these components, you’ll also want to decorate your tank. Read on to learn more.

Decor

You can get creative or aim to make a really natural-looking environment for your fish. The choice is yours! Whatever you choose to decorate your tank with, however, always make sure it is fish-safe.

Pick up a selection of the following items to make a great home for your blue fish:

• Substrate (gravel/sand)
• Hardscape (Driftwood, lava rocks, etc.)
• Decorations and ornaments

Feeding your fish

Different species of fish have different diets, so make sure to research the needs of your blue fish before picking up some food. Read on to learn some popular aquarium fish food types and how to feed your fish!

Food types

Most popular aquarium fish can be fed a regular diet of prepared dried foods. These come in different shapes and sizes and are designed for different types of fish. Prepared foods can either float or sink.

Here are some common examples of prepared foods:

• Fish flakes
• Pellets
• Granules
• Wafers
• Frozen food

Apart from their regular daily food source, omnivorous and carnivorous fish will benefit hugely from the occasional meal of live or frozen food. These should not be provided every day, but rather as a supplement to improve color and condition. The best choices are:

• Frozen brine shrimp
• Bloodworms
• Blackworms

How much to feed your fish

Overfeeding is very bad for the health of your fish and can lead to poor water quality as uneaten food spoils in the water. Most aquarium fish can be fed once or twice a day when the lights are on. Provide only as much food as the fish can finish in a minute or two.

Maintenance

Keeping your fish tank looking amazing requires you to do some regular aquarium maintenance. You’ll need to clean your aquarium glass with an algae scraper when necessary, and you’ll also need to rinse out your filter if it becomes clogged.

The most important side of maintenance is to perform partial water changes once or twice a month. This will prevent the build-up of harmful chemicals in the water.

Testing

You’ll need a test kit to test your aquarium water quality and find out what your water parameters are. Liquid or strip test kits are really easy to use and very affordable. Use your test kit before adding any fish to your tank and then every week to monitor your water quality.

Choose a test kit that can measure the following parameters:

• pH
• Hardness
• Ammonia
• Nitrite
• Nitrate

Where to Buy

Most of the species on this list can be found at your local fish or pet store. If you can’t find what you’re looking for, you can always order from a trusted online retailer and have your new pets delivered to your home!

FAQS

Final Thoughts

There’s something about blue fish that really makes for a great display tank! With all the great species in this list, there’s a species to suit any aquarist. I hope you found some great ideas for your own tank, and remember, have fun!

Do you keep blue fish in your freshwater tank? Tell us about your favorite species in the comments below!

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📘 Want to learn more? This article is part of our complete Freshwater Fish Guide — your ultimate resource for freshwater species, care tips, tank setup, and more.

Brackish water is one of the most underappreciated setups in the hobby, and I’ve always thought it deserves more attention. The species you can keep in brackish — figure-eight puffers, archerfish, mudskippers — you simply can’t replicate in freshwater or saltwater. I’ve kept brackish tanks and the challenge of nailing that salinity range is part of what makes it interesting. This guide covers the 15 species I’d actually recommend for a brackish setup.

Brackish water is one of the most underserved niches in the freshwater hobby — and also one of the most commonly misrepresented at the fish store level. A lot of popular species get sold as “freshwater” when they’re actually brackish: green spotted puffers, archer fish, bumblebee gobies, figure-eight puffers, and more. These fish often survive short-term in freshwater but slowly decline over months without the salt content they need. A true brackish setup uses marine salt at a lower concentration than a reef tank (specific gravity around 1.005 to 1.015) and produces fish with noticeably better health and color. This guide covers 15 species that genuinely thrive in brackish, along with what setting up a proper brackish tank actually involves.

What Are They?

Brackish fish are native to environments where fresh and saltwater mix. These environments are common in coastal areas all over the world, particularly where rivers and streams meet the ocean.

This type of habitat is known as an estuary, although brackish coastal lakes also exist. The salinity of brackish water varies with the tides and other factors like river water levels. As a result, these brackish water fish species must either move with the water or be adaptable to these changeable conditions.

Brackish fish are technically known as euryhaline species¹, which means they can adapt to different salinities. They can often live in fully fresh or marine water for certain periods of time, but they are most comfortable in that in-between range for the long term.

Why Keep this type?

There are many reasons to keep a brackish aquarium. The most obvious is probably because there are some truly amazing-looking brackish fish species! In fact, many of the fish sold as freshwater fish are actually brackish. If you want to give these fish the best care, you’re going to need to go brackish.

Apart from the fish themselves, the brackish environment is a fascinating underwater world. A Brackish water environment is an exciting new challenge for anyone who has started out with a tropical freshwater tank.

15 Best Brackish Water Fish

Now that you know what a brackish aquarium fish is, it’s time to get to know some of the best types! All of these species are suitable for the home aquarium, but their care and space requirements differ very much. I have a video above from our official YouTube Channel for a visual. Our blog will go in more detail below. That’s why I’ve put together the following list of vital stats for each species:

• Scientific Name
• Difficulty Level
• Temperament
• Adult Size
• Minimum Tank Size
• Diet
• Origin
• Temperature
• Water salinity/specific gravity
• pH
• Difficulty to breed

Let’s get started!

1. Mollies

• Scientific Name: Poecilia latipinna, Poecilia sphenops
• Difficulty Level: Easy
• Temperament: Peaceful/semi-aggressive
• Adult Size: 5-7 inches
• Minimum Tank Size: 15 gallons
• Diet: Feed dried and live/frozen food, spirulina/vegetable matter
• Origin: USA, Mexico, Northern South America
• Temperature: 72-82°F
• Water salinity/specific gravity: 1.005-1.015
• pH: 7-8.5
• Difficulty to breed: Easy

Molly fish are highly adaptable fish that can be kept in anything from hard freshwater all the way to full marine conditions. In fact, these inexpensive livebearers thrive in brackish conditions!

There are a few different species and many different breeds available in the fish-keeping hobby. Check out my complete guide for more details on these awesome beginner brackish aquarium fish!

2. Guppy Fish

• Scientific Name: Poecilia reticulata
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 1.5-2.5 inches
• Minimum Tank Size: 10 gallons
• Diet: Feed dried and live/frozen foods, spirulina/vegetable matter
• Origin: Northern South America & Caribbean Islands
• Temperature: 63-82°F
• Water salinity/specific gravity: 1.001-1.010
• pH: 7-8.5
• Difficulty to breed: Easy

Guppies are the smaller, more colorful cousins to the molly fish. These popular livebearers are one of the most common species in the aquarium trade. They are available in an amazing variety of shapes and colors, and they’re really easy to breed in the home aquarium.

Guppy fish is usually thought of as freshwater fish species, but they can be kept in brackish water too. In fact, studies have shown that these amazing fish can even tolerate full marine conditions.

3. Endler’s Livebearers

• Scientific Name: Poecilia wingei
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 1-1.8 inches
• Minimum Tank Size: 10 gallons
• Diet: Feed dried and live/frozen foods, spirulina/vegetable matter
• Origin: Venezuela, South America
• Temperature: 75-86°F
• Water salinity/specific gravity: 1.001-1.025
• pH: 7-8.5
• Difficulty to breed: Easy

The Endler’s livebearer is another great nano brackish fish. These hardy fish thrive in brackish environments, even though they are usually kept in freshwater.

The males of these tiny fish are much smaller and more colorful than the females, so if you don’t want them to breed, males are the better choice. Endler’s livebearers should not be kept with large fish or aggressive tank mates.

4. Archer

• Scientific Name: Toxotes jaculatrix
• Difficulty Level: Moderate
• Temperament: Semi-aggressive
• Adult Size: 12 inches
• Minimum Tank Size: 125 gallons
• Diet: Feed dried & live/frozen foods
• Origin: Widespread in Southern Asia and Northern Australia
• Temperature: 77-86°F
• Water salinity/specific gravity: 1.005-1.010
• pH: 7-8
• Difficulty to breed: Advanced

Archerfish are brackish fish species with a fascinating hunting technique. In their natural habitat, these intelligent fish spit water at insects on leaves and tree branches above the water. This knocks the prey onto the water surface where the fish can get to it. Pretty neat!

They will also take regular flake food and do great in larger brackish water aquariums. These fish are generally very peaceful with other fish but can be a little nippy with other archerfish unless kept in groups of 4 or more.

5. Scat

• Scientific Name: Scatophagus argus
• Difficulty Level: Moderate
• Temperament: Semi-aggressive
• Adult Size: 15 inches
• Minimum Tank Size: gallons
• Diet: Dried foods, live/frozen foods, vegetable matter
• Origin: The Middle East to Australia
• Temperature: 68-82°F
• Water salinity/specific gravity: 1.005-1.025
• pH: 7.5-8.5
• Difficulty to breed: Advanced

Scats are large and beautiful brackish water aquarium fish. These spotted fish look amazing in schools in large aquariums. These curious fish make wonderful pets and are easy to feed and care for.

The secret is to keep them in groups of at least 4 fish, maintain excellent water quality in a large enough tank, and always make sure their water is in the preferred salinity range.

6. Mono

• Scientific Name: Monodactylus argenteus, M. sebae
• Difficulty Level: Advanced
• Temperament: Semi-aggressive
• Adult Size: 10 inches
• Minimum Tank Size: 125 gallons
• Diet: Dried foods, live/frozen foods, vegetable matter
• Origin: Widespread along African and Asian coasts
• Temperature: 75-82°F
• Water salinity/specific gravity: 1.005-1.025
• pH: 7.2-8.4
• Difficulty to breed: Advanced

These beautiful silvery fish are very fast and active so they require a large aquarium with plenty of swimming space. They make great tank mates for other brackish fish like scats, although they do equally well in full marine tanks. Mono fish can be skittish and are known to be fin nippers too, so they are best left to expert aquarists.

7. Green Spotted Puffer

• Scientific Name: Tetraodon nigroviridis
• Difficulty Level: Moderate
• Temperament: Semi-aggressive
• Adult Size: 6 inches
• Minimum Tank Size: 30 gallons
• Diet: Live/ frozen foods, and hard-shelled food sources like snails are essential
• Origin: India to Southeast Asia
• Temperature: 75-82°F
• Water salinity/specific gravity: 1.005
• pH: 7.5-8.5
• Difficulty to breed: Advanced

The green spotted puffer is an amazing brackish water aquarium fish for more experienced fish keepers. These active puffers can be kept with other fish in a community setup, but they should be the only pufferfish in the tank to avoid aggression.

Pufferfish have beak-like teeth that grow continuously. It is very important to feed these fish hard food like snails and shellfish to keep their teeth worn down.

8. Figure 8 puffer

• Scientific Name: Tetraodon biocellatus
• Difficulty Level: Moderate
• Temperament: Semi-aggressive
• Adult Size: 3 inches
• Minimum Tank Size: 20 gallons
• Diet: Live/ frozen foods, hard-shelled food sources like snails are essential
• Origin: Southeast Asia
• Temperature: 72-79°F
• Water salinity/specific gravity: 1.005
• pH: 6.5-7.5
• Difficulty to breed: Advanced

The figure 8 puffer fish is an awesome species that can be kept in both fresh and brackish water conditions. They get their name from the interesting markings on their backs. These little fish are generally peaceful but they are known to nip the fins of slow-moving tankmates

9. Bumblebee Goby

• Scientific Name: Brachygobius doriae
• Difficulty Level: Moderate
• Temperament: Semi-aggressive
• Adult Size: 1-1.5 inches
• Minimum Tank Size: 10 gallons
• Diet: Feed live food
• Origin: Borneo
• Temperature: 72-82°F
• Water salinity/specific gravity: 1.001-1.006
• pH: 7-8.5
• Difficulty to breed: Moderate

These nano fish are best for a small species only tank. They get their name from their bold black and yellow colors. This fish can be a bit of a picky eater and they generally prefer live food.

The bumblebee goby can be a little aggressive with other members of its own species so it is best to keep at least 6 together to prevent anyone from getting singled out. A brackish aquarium with plenty of hiding places is ideal for the bumblebee goby.

10. Dragon goby

• Scientific Name: Gobioides broussonnetii
• Difficulty Level: Moderate
• Temperament: Semi-aggressive
• Adult Size: 15-25 inches
• Minimum Tank Size: 125 gallons
• Diet: Feed algae wafers, live/frozen foods
• Origin: Widespread along the North, Central & South American coasts
• Temperature: 73-79°F
• Water salinity/specific gravity: 1.005-1.015
• pH: 7.5-9
• Difficulty to breed: Advanced

The dragon goby is a strange, eel-like fish. Dragon gobies are actually a whole lot more peaceful than they look or sound though.

They are not known to bother or eat smaller fish, although they can be semi-aggressive to other members of their own species. The Dragon goby can grow really long, so they should be kept in large tanks for good long-term care.

11. Orange Chromide

• Scientific Name: Etroplus maculatus
• Difficulty Level: Moderate
• Temperament: Peaceful
• Adult Size: 3 inches
• Minimum Tank Size: 20 gallons
• Diet: Feed, dried and live/frozen foods, spirulina/vegetable matter
• Origin: India & Sri Lanka
• Temperature: 68-82°F
• Water salinity/specific gravity: 1.002-1.010
• pH: 7-8.5
• Difficulty to breed: Moderate

Orange chromides (video source) can be kept in both fresh and brackish waters. This beautiful fish requires great quality water so regular aquarium maintenance is very important.

They are peaceful but will eat very small fish if they can catch them. Provide your orange chromides with a varied diet that includes both meaty foods and plant matter.

12. Kribensis

• Scientific Name: Pelvicachromis pulcher
• Difficulty Level: Easy
• Temperament: Semi-aggressive
• Adult Size: 3-4 inches
• Minimum Tank Size: 20 gallons
• Diet: Cichlid pellets, frozen/live foods
• Origin: Cameroon and Nigeria
• Temperature: 75-81°F
• Water salinity/specific gravity: 1.000-1.005
• pH: 5-7.5
• Difficulty to breed: Easy

Kribensis cichlids are usually kept in freshwater tanks but they can survive in slightly brackish water too. These fish have beautiful colors and bold horizontal stripes that can really brighten up your tank.

These beautiful West African cichlids are very peaceful except when breeding. It is best to keep a single pair with other fish in a community tank.

13. Golden Wonder Killifish

• Scientific Name: Aplocheilus lineatus
• Difficulty Level: Easy
• Temperament: Semi-aggressive
• Adult Size: 4 inches
• Minimum Tank Size: 20 gallons
• Diet: Feed dried, frozen/live foods
• Origin: India & Sri Lanka
• Temperature: 72-77°F
• Water salinity/specific gravity: 1.000-1.005
• pH: 6-7.5
• Difficulty to breed: Moderate

The golden wonder killifish (video source), or striped panchax, is another great species that can be kept in either fresh or slightly brackish water. These predatory fish will eat smaller fish, so they should only be kept with similarly sized fish. These hardy and adaptable killifish spend most of their time at the top of the tank.

14. Banded Banjo Catfish

• Scientific Name: Platystacus cotylephorus
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 12 inches
• Minimum Tank Size: 30 gallons
• Diet: Sinking dried foods, live/frozen food
• Origin: Widespread in Central & South America
• Temperature: 72-77 °F
• Water salinity/specific gravity: 1.003-1.010
• pH: 6-8.2
• Difficulty to breed: Advanced

The banded banjo catfish (video source) is nocturnal fish with a very unusual body shape. These fish aren’t the most active or exciting to watch, but they still make a great oddball specimen for a brackish tank. They make great community fish but should not be kept with very small fish that could be swallowed whole.

15. Colombian shark catfish

• Scientific Name: Ariopsis seemanni
• Difficulty Level: Advanced
• Temperament: Peaceful
• Adult Size: 12-14 inches
• Minimum Tank Size: 225 gallons
• Diet: Meaty foods, can be picky eaters
• Origin: Coastal regions of eastern Central and South America
• Temperature: 72-78 °F
• Water salinity/specific gravity: 1.015-1.025
• pH: 6.8-8.5
• Difficulty to breed: Advanced

The Colombian shark catfish is not an aggressive fish but it will swallow any smaller fish that it can catch. These are large fish so they should not be purchased unless you have plenty of room.

One important thing to note is that their fins have venomous spines that can cause serious pain and swelling. This means you should be very careful about handling these fish.

Tank Setup

Setting up a great brackish aquarium is not that different from setting up a regular tropical fish tank. Let’s take a look at how to set up a brackish water aquarium.

Substrate & Decorations

You have a few choices when it comes to the substrate for brackish tanks.

Aragonite is an excellent option because it releases calcium carbonate into the water which helps to maintain stable and healthy high pH levels. This substrate looks great and is easy to clean. Aragonite is available in various colors and textures from fine sand to larger particles.

Crushed coral is another great option for a brackish tank but is a little more difficult to maintain because of the larger grain size. You can still get the benefits of this material by putting some into your filter media compartment.

When it comes to decorations, you can use any aquarium safe ornaments that are suitable for saltwater. Rocks are a great choice but small amounts of driftwood can be used too. Avoid large amounts of driftwood, however, since they can leach tannins and lower the water pH to some degree.

Planted Tanks

It will be surprising for some aquarists to hear that you can in fact grow live plants in a brackish water aquarium. The water’s specific gravity or salinity levels certainly do play a role in what kind of plants can be grown, however.

On the higher salinity end, few common aquarium plants will be able to survive. There are options, however, including the various mangrove species, seagrasses, and algae.

Fortunately, many well-known aquarium plants are adaptable to low salinity levels. The following species can be grown in slightly brackish water:

• Marimo moss balls
• Java fern
• Microsword

Lighting & Filtration

Unless you are growing live plants, bright lighting is not required for a brackish tank. The timing of your lighting is important, however. Maintain a regular day/night schedule for your fish by setting your lighting on a timer. 6 to 8 hours per day is recommended.

You can use a regular hang-on back or internal power filter in your brackish water aquarium, but canister filters are preferred because they hold so much more filtration media.

How To Take Care

Apart from their specific salinity needs, brackish fish have much the same needs as any other species. Read on to learn more about caring for fish in brackish aquariums.

Aquarium Maintenance

Performing regular aquarium maintenance is just as important for a healthy brackish aquarium as it is for any other type of fish tank.

Weekly or twice monthly partial water changes and gravel vacuuming will help keep nitrate levels within a safe range for your fish.

Salinity Levels

The main difference between a freshwater tank and a brackish fish tank is the salinity level. Pure freshwater is 1.000 while marine water has a salinity of 1.025. Brackish water aquariums are typically maintained between about 1.005 and 1.012. You can measure salinity with a refractometer and adjust it with calibration solution.

Preparing

Brackish water is prepared by mixing marine salt with fresh water or mixing marine water with fresh water. Not just any salt will do of course! You’ll need to use good quality marine salt for this. Regular aquarium salt does not contain all the mineral elements that occur in natural brackish water.

It is best to use RO water because you will be starting from a ‘level playing field’. If you are using tap water, make sure to mix in a water conditioner to neutralize any harmful chemicals.

Always mix up the water before adding it to your aquarium. Mix up your water in a separate bucket so you can siphon out the old water into one bucket, and add the new water right after.

Testing

Apart from a regular water test kit that all fishkeepers should have, there’s one extra piece of equipment you will need. Since you will be mixing salt into your water, you’ll need a device to help you measure and monitor the salinity in your tank.

You can opt for an inexpensive hydrometer if you’re happy with ‘ballpark’ readings. This is usually perfectly fine for brackish tanks because the animals tend to be quite adaptable.

For more accurate readings, spend a little more and pick up a decent refractometer. Whichever instrument you choose, make sure to test your salinity (and other parameters) after each water change.

Where To Buy

Brackish water species are not as easily available as freshwater species, but you can still find them at your local fish store from time to time. Common species like sailfin mollies and guppies can be found just about anywhere, but I would recommend trusted online retailers for the more exotic species.

FAQS

Final Thoughts

Setting up a brackish tank can be a great next step for aquarists looking to expand their collection. The range of different fish that this side of the hobby opens up is really exciting. This is a fascinating side of the hobby that all fish keepers should try out!

Do you keep brackish fish? Tell us about your favorite species in the comments below!

Livebearers were some of the first fish I kept, and after 25+ years in the hobby they’re still fish I recommend constantly. Guppies, platies, mollies, swordtails — they’re forgiving, colorful, and actively breed in captivity, which makes them fascinating to watch. This guide covers the 5 main groups, what makes each one unique, and what beginners actually need to know before getting started.

Livebearers — guppies, platies, mollies, swordtails — are the backbone of the beginner freshwater hobby, and for good reason. They’re hardy, colorful, and active. They also breed constantly, which is either a feature or a problem depending on how you set up your tank. I always tell people: if you keep males and females together, plan for fry. It’s not optional. Either keep one sex, get a tank large enough that fry can hide and survive, or be ready to manage the population. Beyond that, livebearers are about as forgiving a fish group as you’ll find. Here are the 5 main types worth knowing.

What Are Livebearers?

Livebearers are often overlooked in the aquarium hobby (see video above from our YouTube Channel). Their cheap fish that are easy to keep and more experienced hobbyists see them as not being worth their time; these hobbyists have advanced onto harder and more challenging species, so there’s no reason to keep something so easy.

In our opinion, livebearers are some of the prettiest and most active fish available in the hobby and belong in every community tank setup! However, there is just one problem. There is a reason they’re known as livebearers.

There are over 300 different species of fish that are categorized as livebearers. In the aquarium hobby, the most known livebearers belong to the Poeciliidae family, including guppies, platies, mollies, and swordtails. These fish have their eggs internally fertilized and then give birth to live, free-swimming fry. This is in contrast to most other fish that lay eggs which then get fertilized.

What Is The Best Fish?

That being said, which livebearer is the best out of all of them? Well, that depends.

As we’ll see, these are some of the easiest fish to keep in the aquarium industry and one isn’t necessarily better than the next. However, each one brings a unique experience to the tank that another can’t.

For example, mollies can be adapted to live in brackish or saltwater conditions instead of freshwater, bringing a new challenge to an otherwise easy species. Many hobbyists also find it interesting to add these mundane fish to more elaborate setups with uncommon tank mates, like piranhas with common guppies.

The best livebearer fish for your aquarium setup will be the ones that match water parameters and compatibility levels.

Male Vs Female Differences

When choosing livebearers for your freshwater aquarium, it’s important to know the difference between males and females. This is for a few reasons.

1. Harassment. Livebearers do not need much time between broods. Within a few weeks after birth, they’re able to safely reproduce again. This can lead to some problems with males being overly excited with females. If the ratio between male and female livebearers is low, then the females can be stressed out due to males chasing them to mate.
2. Overpopulation. The biggest problem with having more than one livebearer in the aquarium is that they’ll quickly reproduce. In order to prevent this, some hobbyists stick to keeping only one sex in the aquarium.

In order to prevent harassment and overpopulation, it’s important to know the difference between male and female livebearers. In general, male livebearers are smaller and more colorful but the difference isn’t so clear with every species.

Here are the differences between the 5 main types of livebearers. Video below is also for visual reference from Albert’s Guppy Adventure:

• Guppy fish. Female guppies are plain in color, with a yellowish-brown body. The tail fin may have some coloration or patterning and the dorsal fin is short. Male guppies have colorful bodies and fins but are smaller than females. The dorsal fin is elongated.
• Endler’s livebearers. Female Endler’s are also plain in color, with a silver or tan body. The fins are usually transparent. Male Endler’s livebearers have coloring and patterning across their body and are smaller than the females.
• Platies. Platies are the most difficult fish to correctly sex on this list. Female platies have a fan shaped anal fin while male platies have a pointed anal fin. Females are also larger on average.
• Mollies. Mollies are identified in the same way as platies; females also have a modified anal fin while males have a pointed anal fin.
• Swordtails. These fish are one of the easiest to tell apart! Male swordtails have a special elongated bottom tail fin ray and a streamline body. Females lack this feature and are much rounder in appearance.

When shopping for livebearers, try to keep one male for every three females. Ask the associate to pick out male and female fish or ask them to catch specific fish to keep this ratio balanced.

5 Main Types

Out of the many various species of livebearer, five seem to be the most popular. These include:

1. Guppy Fish
2. Endler’s Livebearers
3. Platies
4. Mollies
5. Swordtails

1. Guppy

• Scientific Name: Poecilia reticulata
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 2 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: South America and parts of the Caribbean
• Temperature: 64-82°F
• pH: 5.5-8.0
• Difficulty to breed: Easy
• Planted tank suitability: Common

Guppy fish can be found everywhere and in every color. Though they originate from South America and the Caribbean, it is nearly impossible to find wild-caught individuals.

In general, there are two types of guppy: fancy guppies and feeder guppies. However, these freshwater fish aren’t different at all and are actually the same species. The only difference is that some fish are prettier and deemed as more desirable as others that might not be as big or colorful; the undesirable species get left to be fed to other fish.

Fancy guppies are usually the first fish anyone ever has. They’re colorful, small, inexpensive, and can survive most beginner mistakes. They need a minimal freshwater setup and can even survive ambient room temperatures. As a livebearer, they will quickly reproduce and overpopulate an aquarium if left unmonitored.

They should not be confused with mosquito fish, Gambusia affinis. Their lifespan can be anywhere from 2-5 years.

2. Endler’s

• Scientific Name: Poecilia wingei
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 1 inch
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Venezuela
• Temperature: 64-82°F
• pH: 5.5-8.0
• Difficulty to breed: Easy
• Planted tank suitability: Common

Endler’s livebearers are very closely related to guppies and share many of the same behaviors and care requirements, though slightly smaller and streamline in appearance. In some ways, Endler’s are more desirable than guppies and have been selectively bred to bring out the best colors and patterns.

Endler’s are nearly extinct in the wild due to run-off and habitat destruction. They have been found living together with common guppies, though they are likely to hybridize and create fertile offspring in the aquarium setting. This can be a desirable mix for some fish keepers but can also ruin a rare wild lineage of Endler’s.

3. Platies

• Scientific Name: Xiphophorus maculatus
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 2 inches
• Minimum Tank Size: 20 gallons
• Diet: Omnivorous
• Origin: Central America
• Temperature: 64-77°F
• pH: 7.0-8.2
• Difficulty to breed: Easy
• Planted tank suitability: Common

Platies are a larger type of livebearer that can bring immense amounts of color and activity to the aquarium. Some varieties of platy include wagtail, salt and pepper, tuxedo, and rainbow; there is even a dwarf platy variation that is bright red for smaller nano tanks.

These fish prefer to stay towards to the top of the tank, but will venture to lower portions unlike guppies or Endler’s. It is recommended to have a larger tank for these fish as they can produce significant amounts of waste in a short period of time and like to be active.

4. Mollies

• Scientific Name: Poecilia sp.
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 5 inches
• Minimum Tank Size: 30 gallons
• Diet: Omnivorous
• Origin: South America and Central America
• Temperature: 68-82°F
• pH: 7.0-8.0
• Difficulty to breed: Easy
• Planted tank suitability: Common

There are a few different species of molly available: common mollies (Poecilia sphenops), balloon mollies (Poecilia latipinna), and sailfin mollies (Poecilia latipinna). Balloon mollies have an inflated stomach and noticeably shorter body while sailfin mollies have very extended dorsal fin rays. They come in a variety of colors, including white, yellow, black, red, and dalmatian patterning.

In the wild, mollies live in brackish water conditions where rivers meet the ocean. Because so many of these fish have been bred within the aquarium hobby, most of the ones sold in stores have lived in freshwater conditions their entire lives.

However, with some patience, these fish can be acclimated to saltier conditions. In fact, some fish keepers use mollies as a way to treat pest algae in their saltwater setups. This makes them a very interesting addition to the traditional reef stocking list!

5. Swordtails

• Scientific Name: Xiphophorus helleri
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 4 inches
• Minimum Tank Size: 20 gallons
• Diet: Omnivorous
• Origin: Central America
• Temperature: 64-82°F
• pH: 7.0-8.3
• Difficulty to breed: Easy
• Planted tank suitability: Common

Swordtails are probably the least popular species on this list, but that’s only because of their size. These are big fish that need to be kept in schools and many hobbyists aren’t willing to allot that real estate to a beginner fish. Still, these fish come in a bunch of vibrant colors and can bring a ton of activity to the middle and lower portions of the tank.

There are a few variations of swordtail, including lyretail and hi fin, though they are typically limited to red coloration.

Tank Setup

Livebearing fish do not need much to make them happy. The biggest problem hobbyists run into is overpopulation as the minimum recommended tank size is only 10 gallons. These nano fish tanks are good for a starting group of these fish, but will quickly become too small once the fish start to reproduce.

A 10 gallon tank is recommended for hobbyists who are able to control the populations of their fish. Otherwise, a bigger setup will be needed in the longrun.

Substrate & Decorations

Livebearers can be kept on either a sand or gravel substrate. These fish do not typically go towards the bottom of the aquarium, saving their fins and bodies from any potential injuries.

Elaborate decorations are also not needed as they will stay out in the open as long as conditions are met. On the contrary, some fish may hide when there are too few decorations available. If you find that your fish are hiding, check aquarium water parameters and add additional hiding spots.

Live plants are the best decorations you can add to your aquarium fish tank. Not only do they provide shade and coverage for your fish, but livebearing fish will also love to pick at any algae that’s growing on the leaves and stems. Not to mention the additional nutrient export and oxygenation that live plants provide!

Lighting & Filtration

Livebearers do not require any special lighting. However, since some of these fish like to stay towards the surface of the water, it’s important to keep in mind that some lighting can be too strong. To help make your top swimmers more comfortable, try adding floating plants.

In general, it’s recommended to provide fish with a filter that is rated for 2x the water volume of the tank. For livebearers, it’s better to have too much filtration as these fish quickly produce waste. Some of these tiny fish, like Endler’s, can be pushed around by an overly strong water current, though. A power filter tends to serve them well in fish only tanks while canister filters are good to invest in for heavily planted aquariums.

Heating

Livebearers are extremely hardy and will survive swings in water temperature. They can withstand cooler temperatures more than regular tropical fish and bounce back from fluctuations in water conditions. However, no fish can acclimate if temperatures change too rapidly.

Even though most livebearer fish prefer ambient room temperature, they will stress out if temperature fluctuate too often. We always recommended using an aquarium heater, even for coldwater species, to help keep warm temperatures stable rather than to raise temperature.

How To Care

Once the aquarium is mature, there is little to no additional care needed for livebearers. As mentioned before, the biggest upkeep will be keeping populations under control. This can be done by stocking either only female or male livebearers or by giving away or rehoming fry as needed.

Otherwise, aquarium maintenance is easy and straightforward.

Aquarium Maintenance

Like any fish tank, livebearers need regular water changes to help keep parameters in check. This usually means about a 20-25% water change every week or every other week. The substrate should also be siphoned during this time to remove uneaten food and other waste.

Behavior & Feeding

Livebearers are not picky and will eat anything that they can fit into their mouths. For some fish, like Endler’s, this might mean breaking up fish flakes and pellets for easier eating.

These fish are naturally omnivores and will accept both meat- and plant-based foods; this includes mosquito larvae and bloodworms as well as algae wafers and blanched vegetables.

For protein, livebearers can be given a high-quality fish flake or pellet. Floating foods may be easier for some livebearers to eat as they don’t like to go all the way down to the bottom of the tank.

Tank Mates

Most species of community fish can be kept with most livebearers. They are the ideal tank mate in regards to temperament, space requirements, and color, and can be used to accent other larger fish.

Some of these compatible species include:

• Tetras
• Danios
• Rasboras
• Gouramis
• Corydoras
• Angelfish – only with large livebearers like Swordtails and Mollies. Not Guppies.

It should also be noted that most livebearing fish can be kept with large invertebrates, like shrimp and crayfish. While this pairing isn’t always guaranteed to work, both the fish and the invertebrate tend to stay out of reach from one another.

In regards to Betta Fish, most livebearers are compatible with female bettas. Male bettas are considered with caution, with them being more successful with Endler’s livebearers due to their speed.

Tank Mates To Avoid

Livebearers are small fish. They can easily be eaten or harassed by other larger fish. Some hobbyists use this to their advantage to feed other fish and either buy or cultivate feeder guppies.

In general, you want to avoid keeping livebearers with fish that could easily swallow them. Some of these tank mates include:

• Cichlids
• Oscars
• Discus

Breeding

Each livebearer will be different, but the breeding process is pretty much the same for all of these aquarium fish.

First, make sure you have a group of males and females. This should be relatively easy as there is usually a big difference in appearance between male and female livebearers. When both fish are ready to spawn, they will intensify in color. Females will become noticeably rounder while males will become more persistent and aggressive.

The tank should be well-planted to ensure that newborn fry can hide and survive or else they will be eaten by their parents and other livebearers. A pregnant female will develop a dark spot near her anal fin called a gravid spot. She will be pregnant for about 4-6 weeks until she’s ready to birth up to 100 young.

These live young can be removed from the aquarium to ensure survival and to prevent inbreeding. They can be fed small foods, such as baby brine shrimp until they’re ready to accept bigger foods and rejoin the rest of the fish.

By picking and choosing which males and females you want to mate with, you can control selective breeding to get new colors and patterns.

Final Thoughts

Having easy fish doesn’t necessarily mean that you don’t know what you’re doing with your aquarium! Livebearing species are a great choice for any hobbyist at any skill level. They’re colorful, inexpensive, and incredibly active fish that can fill up an empty tank or accent other featured fish.

As long as population growth is kept in control, livebearers will enjoy grouping with themselves and foraging on algae in community tanks.

Danios are one of those fish groups I’ve always had a soft spot for — they’re fast, hardy, and the group contains a lot more variety than most hobbyists realize. Most people know zebra danios, but there are 9 species worth keeping and each has its own personality and requirements. After 25+ years in the hobby, here are my honest notes on the whole group.

Danios are one of those fish groups that punch above their weight. The common zebra danio is practically bulletproof — it tolerates a wide temperature range, adapts to most water conditions, and its active schooling behavior makes it a useful dither fish for shy or nervous tankmates. But the group goes well beyond zebras: pearl danios, giant danios, leopard danios, and the stunning celestial pearl danio all have their own appeal. After 25 years in the hobby, I still think danios are underrated by intermediate hobbyists who’ve moved past the beginner stage. Here are 9 types worth knowing.

What Are Danio Fish?

Danio fish are some of the most important fish in the aquarium hobby as well as in the scientific world. The most popular species of danio to come across is the common danio (Danio rerio), also known as zebrafish. However, the genus of Danio contains almost 30 different species with 9 of them making their way into the homes of freshwater enthusiasts!

Danio fish are considered to be some of the easiest fish to keep in the home aquarium. Their hardiness and quick reproduction rates have also made them the perfect candidate for use as a model organism for gene sequencing. Specifically, Danio rerio has been used to study drug development, regenerative properties, and other bioengineering practices.

Some of these studies have been taken advantage of by the aquarium industry, creating fluorescent varieties of danio called GloFish. These fish have been genetically prioritized to express neon colors of red, green, yellow, and more. Once these genes are expressed, they will continue to be passed onto later generations of danio, meaning that there is no cruel practice involved. Sadly though, there are many breeders that dye their fish for brighter and more appealing colorations.

Top 9 Types of Danios Best Suited For Aquariums

In the freshwater aquarium hobby, danios are seen as beginner fish. They don’t require a lot of room to thrive and can bring a ton of activity to the top portions of the tank. Though common zebra danios are the most popular fish species available, there are actually 8 other varieties that can bring new life to a tropical setup.

We have a video just for you from our Aquarium Store Depot YouTube Channel. We go into more detail in our blow post below. If you enjoy our content, please subscribe as we post new videos each week! Let’s start with the first on the list!

1. Celestial Pearl Danio

• Scientific Name: Danio margaritatus
• Difficulty Level: Moderate
• Temperament: Peaceful
• Adult Fish Size: 1 inch
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Burma
• Temperature: 65-80°F
• pH: 6.5-7.5
• Difficulty to breed: Moderate
• Planted tank suitability: Common

Sometimes wrongly referred to as galaxy rasboras, celestial pearl danios belong to the Danio genus along with the other fish species on this list. These fish are a recent addition to the aquarium hobby, almost causing them to become endangered shortly after their discovery in 2006. Their spotted trout-like appearance has made them a favorite, yet expensive, staple to the planted aquarium.

Celestial pearl danios come from very specific ecosystems at high altitudes in Hopong, Burma. They can be found in large groups, which needs to be replicated in the aquarium setting by keeping at least 6 members at all times; ideally, these fish should be kept in large groups starting with 20 individuals.

Celestial pearl danios can be slightly more challenging to keep as they are not very hardy fish and succumb to imperfect or irregular water conditions. They also do better in cooler water temperatures, making them incompatible with other species.

2. Zebra Danios

• Scientific Name: Danio rerio
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Fish Size: 3 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Pakistan, India, Bangladesh, Nepal, and Myanmar
• Temperature: 64-75°F
• pH: 6.5-7.5
• Difficulty to breed: Easy
• Planted tank suitability: Common

Zebra danios are arguably the most popular and available fish on this list. These are incredibly active fish that earn their name from the horizontal black and yellowish-silver stripes that run from their heads to their tails.

In the wild, the Zebra danio fish are found in a wide range of ecosystems from stagnant waters to fast-moving mountain streams. Most of these environments have cooler water temperatures than typical tropical fish, which will need to be replicated in the aquarium.

The zebra danio is a schooling fish and will need to be kept in groups of at least 6 or more. Due to their activity and tendency to stay towards the top of the tank, schools can quickly become overwhelming for other fish as well as for other danios. Because of this, it’s recommended to keep smaller schools with other species that stay toward the bottom of the aquarium.

3. Gold Longfin Danio

• Scientific Name: Danio rerio
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 3 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: India
• Temperature: 64-75°F
• pH: 6.5-7.5
• Difficulty to breed: Easy
• Planted tank suitability: Common

The gold longfin danio (video source) is a more colorful variation of the common Danio rerio. These types of danios naturally occur in the Ganges region in Eastern India, though the aquarium hobby has enhanced their coloration and finnage.

The gold longfin danio is named after its bright yellow body with white stripes. Compared to other species, they also have noticeably longer fins. In terms of care requirements, they have the same needs as regular Danio rerio fish.

4. Gold Ring Burmese Danio

• Scientific Name: Danio tinwini
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 2 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Myanmar
• Temperature: 64-75°F
• pH: 6.5-7.5
• Difficulty to breed: Easy
• Planted tank suitability: Common

Though similar in name to the gold longfin danio, the gold ring Burmese danio (video source) is a species all of its own. Instead, these unique fish are named after the leopard-like black spots that cover their pale yellow body. They are especially identifiable by their opaque white abdomen.

https://youtu.be/gT0X7RLFCpc

Gold ring danios have the same behaviors and care requirements as zebra danios, but are slightly smaller. Though an inch difference might not seem like a lot, these fish are that much more susceptible to bullying and strong water currents. Still, the best tank mates for gold ring danios will be other types of danio and slow-moving fish species.

5. Glowlight Danio

• Scientific Name: Celestichthys choprae
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 1.5 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Myanmar
• Temperature: 64-75°F
• pH: 6.5-7.5
• Difficulty to breed: Easy
• Planted tank suitability: Common

Not to be confused with GloFish danios, glowlight danios are very unique fish. They’re not even true danios and belong to the Celestichthys genus instead!

These fish are extremely colorful with a yellow-based body with vertical blue stripes and a pink stripe leading to their tail. They are also much smaller than the other types of danios on this list, but one of the more expensive varieties.

Glowlight danios are very tight schoolers and will thrive in large groups. They are more likely to venture to lower portions of the other tank than other species, so it’s important to keep their activity levels in mind when stocking.

6. Pearl Danio

• Scientific Name: Brachydanio albolineatus
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 2 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Myanmar, Sumatra
• Temperature: 73-77°F
• pH: 6.5-7.5
• Difficulty to breed: Easy
• Planted tank suitability: Common

The pearl danio, also known as the blue danio or turquoise danio, is a plain iridescent fish. While they may not be the most colorful species on this list, their simplicity catches the eye in a well-planted aquarium.

Pearl danios have the same care requirements and behaviors as other danios and will do best when kept in small groups. It is important to note that pearl danios need a slightly higher water temperatures than other types of danios that can tolerate cold climates.

7. Leopard Danio

• Scientific Name: Danio frankei
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 3 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: India
• Temperature: 64-75°F
• pH: 6.5-7.5
• Difficulty to breed: Easy
• Planted tank suitability: Common

The leopard danio is very close in appearance to the gold ring Burmese danio, though they’re not related. Leopard danios have slightly more streamlined bodies and much smaller bluish-black spots on a light yellow body. Some of these spots transfer onto the fins.

Unlike other danios, the leopard danio fish occurs in slow-moving or stagnant waters. However, they appreciate some water flow in the aquarium setting. Like the others, they appreciate being in small groups in vegetative setups.

8. Giant Danio

• Scientific Name: Danio aequipinnatus
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 4 inches
• Minimum Tank Size: 30 gallons
• Diet: Omnivorous
• Origin: India, Nepal
• Temperature: 72-75°F
• pH: 6.0-7.0
• Difficulty to breed: Easy
• Planted tank suitability: Common

Though called giants, giant danios are only about an inch bigger than other species of this fish. However, this potential size is enough to make their minimum tank size a little bigger than the others to allow for growing room and space to swim. They also prefer slightly warmer water temperatures and a lower pH.

These aquarium fish are plain in color, but beautiful upon a closer look. They have pale bodies with highlights of light blue. Paired with their activity level, they can create contrast against a planted background in a large group.

9. GloFish Danio

• Scientific Name: Danio rerio
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: 2.5 inches
• Minimum Tank Size: 10 gallons
• Diet: Omnivorous
• Origin: Captive-bred
• Temperature: 64-75°F
• pH: 6.5-7.5
• Difficulty to breed: Not permissible
• Planted tank suitability: Common

GloFish are highly fluorescent types of danio. This trait has been inherited through the generations and patented by the GloFish company, making it illegal to breed them. However, they are widely available in most aquarium stores and can make a fun and unique addition to a blacklight freshwater setup.

It is important to purchase only GloFish (certified danio fish as others could be cruelly dyed with artificial colors. GloFish danio colors include Starfire Red®, Electric Green®, Sunburst Orange®, Cosmic Blue®, and Galactic Purple®.

Danio Tank Setup

The best thing about danios is that they will thrive in most tank setups, anything from a simple 10 gallon tank with colorful decorations to a 100 gallon system with the rarest freshwater plants. As long as water parameters stay stable and in their preferred range, these fish will thrive.

Substrate & Decorations

Danio fish can be kept on gravel or sand. They do not regularly venture towards the bottom of the tank, which nearly eliminates the threat of long fins getting tugged or bodies getting scratched. If you find that your fish is laying towards the bottom of the aquarium, check water parameters immediately as this could be a sign that something is wrong.

Otherwise, danios do not need an elaborate setup. They will do well in a barebones aquarium with simple decorations. If you really want to treat your fish though, provide easy floating plants that they can pick at for food and hide in at the surface of the water.

A fully planted setup will make these simple and peaceful fish shine even more.

Lighting & Filtration

Lighting will largely depend on the types of plants being kept in the aquarium. Danios do not need any specific lighting, though GloFish will glow best under a blacklight; don’t be tricked into buying a special aquarium blacklight as any one will work.

An important thing to remember is that these fish stay towards the top of the aquarium. If using a high-intensity light for red and foreground plants, make sure to provide your fish with some coverage that they can escape to if the light becomes too much.

Though danios aren’t the messiest fish, they can start to create large amounts of waste when kept in big groups. It is always recommended to have a filter that is rated for at least twice the size of the aquarium, with bigger being better. In most cases, you can’t overdo good filtration for danios as they’ll appreciate the extra water flow. A simple power filter should do the trick for a danio tank.

Heating

Danio fish are considered a coldwater species. They can tolerate significantly colder water temperatures than typical tropical fish. However, most of these fish have been bred in the aquarium industry and have acclimated to average water conditions.

When buying your danio, it is best to ask what temperature they are being kept at and match those parameters.

Do Danios Need A Heater?

Being a coldwater fish, danios do not necessarily need a heater. If ambient room temperature constantly stays in the same range as the preferred one of your danio, then you don’t need a heater.

However, a heater is always recommended for any tank setup. This is because temperatures can easily fluctuate throughout the day enough to cause stress on your fish. For that reason, danios should always have a heater to keep temperatures constant rather than to raise the temperature.

How To Care For Danio Fish

Danio care is simple and straightfoward. Once the tank is cycled and the fish are safely acclimated, there’s little to worry about going wrong. The biggest concern will be keeping these active aquarium fish fed and choosing the right tank mates.

Aquarium Maintenance

Danio aquarium maintenance is no different from any other fish though the frequency will depend on the parameters of your system. This usually means a 20-25% water change every time nitrates creep over 50 ppm. For most hobbyists, this is every week or every other week depending on the bioload and size of the aquarium.

Along with water changes, the substrate should be vaccuumed regularly to keep detritus from building up.

Danio Behavior & Feeding

No matter which species of danio you choose, your danio fish will be the most active in the whole aquarium. These fish love to swim towards the surface of the water, searching for food and following the rest of the school. Most species of danio are very tight schoolers and will form groups that change direction all at once.

If you find that your danios are not schooling, try adding more plants or more danios. It is possible that your fish are trying to hide due to lack of coverage or safety in numbers. To help your fish be more active, make sure to feed regularly. More activity means a higher metabolism that needs to be kept up with.

In the wild, danios are mainly insectovores; this is part of the reason they stay right under the surface of the water to catch any bugs that might land. In the aquarium setting, they have adapted to an omnivorous diet and will accept most frozen, freeze-dried, and live foods. They will especially enjoy bloodworms and mosquito larvae.

The staple of their diet should be a high-quality fish flake food or pellet; flakes will stay on the surface while pellets will sink out of reach of your fish. To meet their vegetation needs, you may provide algae flakes and pellets or offer blanched vegetables from time to time. A good staple food to buy is Xtreme Aquatic Foods Nano.

Danio Tank mates

Most danios are plain in color. While they can bring a lot of activity to the tank, they’re not usually the centerpiece of the system. Instead, their simple colors can be used to accent other aquarium fish.

Some of the best danio tank mates will prefer cooler temperatures and stay away from the upper portions of the tank. Some ideal species would be:

• White cloud mountain minnows
• Corydoras
• Tetras
• Gouramis
• Angelfish

Danios can also safely be kept with most invertebrates and can even be paired with dwarf crayfish as they both stay at the extreme ends of the tank.

How Many Danios Should Be Kept Together?

No matter which species of danio you choose, you will need to keep them in a school. Danios are schooling fish and should never be kept by themselves.

Ideally, at least 6 danios should be kept together at all times. From there, tank size will determine the maximum number possible.

Tank Mates To Avoid

There aren’t many tank mates you should avoid in a danio tank. The biggest concern will be having your fish eaten by something that has a bigger mouth.

In general, this includes:

• Cichlids
• Oscars
• Discus
• Aggressive barbs

Danio Breeding

Danios are some of the easiest freshwater fish to breed and are a perfect challenge for beginners. As long as water parameters are stable, diet is high-quality, and a male and female are available, then these fish will spawn in your freshwater aquarium without any additional effort.

Danios are egg scatterers and will not take care of their young. Once the eggs have been fertilized, they are likely to be eaten by other fish. To increase the odds of eggs surviving, remove the eggs or install an eggcrate that blocks the other fish from getting to them.

The eggs will hatch after a day or two and the fry will be free-swimming. At this point, the fry can also be removed for greater chances of success. Feed small foods, like baby brine shrimp, regularly until they’re able to accept a larger variety.

Final Thoughts

Danio fish are shrugged off as an easy beginner fish that doesn’t add much to the aquarium. Most hobbyists forget that there are many different types of danio available that don’t need any extra care! It’s just a matter of picking out which one you like best.

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📘 Want to learn more? This article is part of our complete Freshwater Fish Guide — your ultimate resource for freshwater species, care tips, tank setup, and more.

Guppies were one of my first fish, and decades later I still think the variety in this group is genuinely remarkable. Most hobbyists pick guppies based on color without realizing how different the tail shapes and patterns can be. After keeping many varieties over the years, I put together this visual guide to the 21 most recognizable guppy types — with notes on what makes each one stand out.

Guppies get written off as beginner fish, and while that’s fair — they’re genuinely forgiving — the variety within the species is something most hobbyists underestimate. Fancy guppies have been selectively bred for decades into dozens of distinct tail shapes and color patterns: delta tails, veil tails, sword tails, mosaic patterns, cobra patterns, and more. Serious guppy breeders treat this like a competitive show hobby, and the results are impressive. Even if you’re not getting into breeding, knowing the different types helps you pick what you actually want instead of grabbing whatever the store happens to have. Here are 21 guppy varieties worth knowing.

What Is a Guppy Fish?

Guppies are small fresh and brackish water fish from the Poeciliidae family. There are many popular aquarium fish in this group, including mollies, plays, and swordtails. They are livebearers, which means they do not lay eggs but rather give birth to live free-swimming fry.

Here is a YouTube from my YouTube channel to get you started. I’ll go into more in detail in this post. If you like videos like this, please make sure to like and subscribe!

Read on to learn all about guppies, their care, and the different types that you can keep and breed!

What Makes Them Such Great Pets?

Guppies are probably the best beginners fish in the hobby, but that doesn’t mean they aren’t excellent for experienced fishkeepers too.

Guppies are:

• Very affordable
• Highly attractive
• Easy to care for
• Easy to breed
• Active and fascinating to watch

Guppies seem to have it all!

In Their Natural Habitat

Guppies are adaptable to a variety of natural habitats in their native distribution. They prefer slow-moving or still waters and are most at home in pools of streams and rivers or ponds and swamps. These fish are mostly found in freshwater although they have been recorded in brackish water too.

Guppy fish have also established populations all over the world after being released into the wild to control mosquito larvae. They also populate local waterways when they are released from fish tanks or escape from ponds. Who knows, there could even be some wild guppies near your home!

The History Of Guppy Keeping

The guppy was first sent to Europe from the Caribbean island of Trinidad. The name of the man responsible for introducing this fish to the hobby was Robert John Lechmere Guppy, and the year was 1866. The fish was officially named Giradinus guppyi¹.

He was not the first European to discover the fish, however, that honor goes to a German man named Julius Gollmer who found these fish in the wild many years before. Guppies have been kept for over 150 years, and they are just as popular as ever!

The International Guppy Associations

Fancy guppies are bred and kept all over the world. International associations have been created to bring hobbyists together and attempt to standardize the hobby. The International Fancy Guppy Association (IGFA) is one of the best examples.

IGFA was founded in 1965 and has developed show standards for the various breeds of fancy guppy. They are also a great resource for keepers who would like to learn more about the fascinating world of guppy breeding.

The IKGH is another very important international association that was formed in 1981. They have been active in the guppy breeding hobby ever since, holding regular shows and competitions all over the world.

3 Types by Species

There are many wild guppy fish species, but the three most commonly kept types are listed below.

1. Micropoecilia picta

• Common name: Scarlet livebearer, swamp guppy, painted guppy
• Adult size: 1.2 inches
• Origin: South America, Caribbean
• Temperament: Peaceful
• Water type: Fresh/brackish
• Minimum tank size: 15 gallons

The scarlet livebearer is a brackish water species that is found in the Caribbean and Countries like Brazil and Guyana. They are also known as swamp guppies or painted guppies.

They have red or orange overall color but are also boldly marked with various other colors. Females swamp guppies are larger than males. They are a hard water species and they are at home in slightly brackish water.

2. Poecilia wingei

• Common name: Endler’s livebearer, Endler’s guppy
• Size: 1-1.8 inches
• Origin: Venezuela
• Temperament: Peaceful
• Water type: Fresh/brackish
• Minimum tank size: 10 gallons

Endler’s livebearer is an awesome nano guppy species from Venezuela in South America. Endler guppies reach a maximum size of about 1.8 inches. The males are much smaller and more colorful than the females.

3. Poecilia reticulata

• Common name: Common guppy, fancy guppy
• Size: 1.5-2.5 inches
• Origin: South America, Caribbean
• Temperament: Peaceful
• Water type: Fresh/brackish
• Minimum tank size: 10 gallons

The common guppy is one of the most popular aquarium fish on the planet. These fish are available in a huge variety of breeds known as fancy guppies.

They are native to the northeastern parts of South America and the Caribbean islands. They grow to about 2.5 inches in length, with females growing larger than males.

21 Types by Variety

Now that you know a little more about guppies and their history, it’s time to learn about some of the amazing fancy guppy varieties out there in the hobby. I’ll provide a brief explanation of the most important features of each type.

Before we get started, here are a few important terms to know:

• Dorsal fin: The fin on the back of a fish. The shape and length of this fin are important for identifying many of the fancy guppy breeds.
• Pectoral fin: The pectoral fin is located on the side of a fish’s body, just behind its head. There is a pectoral fin on either side of the body.
• Caudal fin: Caudal fin is the technical name for a fish’s tailfin. Tail shape and tail patterns vary pretty extensively between the different guppy types.

Now that we’re all up to speed on the fancy fishy words, let’s jump right in and meet some fancy guppies!

1. Fantail

The fantail guppy is a very common breed that is easy to find. The males have large, beautiful caudal fins that are about as long as the fish’s body! The standard for the breed is a long, triangular tail with straight edges.

The dorsal fin is also a distinctive feature of this breed. It should sweep back to about the first third of the tail.

2. Delta Tail

The delta tail guppy (video source) is also known as the triangle tail guppy. They are very similar to the fantail guppies but the outer edge of their tail is slightly convex (rounded outwards). Delta tail guppies come in all sorts of different colors and patterns.

3. Lyretail

Lyretail guppies have very interesting tail shapes. In case you were wondering, a lyre is an ancient U-shaped musical instrument, and that’s where these fish get their name.

This tail shape is similar to the double swordtail, but the extensions curve outwards slightly, instead of being straight and parallel.

4. Roundtail

Round tail guppies (video source) have a circular tail fin with a diameter about half the length of their body. Their dorsal fin is pretty long and has a rounded end. The round tail guppy breed is available in a huge range of different colors and patterns, so there’s a round tail to suit any fishkeeper’s eye!

5. Half-moon Tail

https://youtu.be/Ub1VsZY-0Q0

The half-moon tail guppy (video source) is similar to the round tail but has a larger, fuller caudal fin. The tail is semicircular, starting at 90 degrees (right angles) to the fish’s body.

The tail is not quite as long as the body but can be even taller than the fish is long! The dorsal fin on halfmoon tail guppies is also large and overlaps the tail a little.

6. Spear Tail

The spear tail guppy is another interesting fancy guppy breed. These fish have rounded tails that form a point in the middle, just like a spear tip.

The dorsal fin shape of this breed is also a great feature. It starts at nearly 90 degrees to the body and sweeps back to about a third of the length of the tail fin.

7. Pin Tail

The pintail or needle tail guppy (video source) has a small circular tail shape with a sharp point extending from the middle. It is very similar to the spear tail guppy in this respect, but the pointed caudal fin is even more prominent in this breed. The dorsal fin is also quite long and sharply pointed, creating a bold and dramatic-looking fancy guppy.

8. Tuxedo

Tuxedo guppies (video source) are very elegant little fish, just as their name suggests! This popular breed was first developed in Germany.

The tail half of their body is black or another solid color. The tail and dorsal fin will also be a different color to the dark half of the body, but without any spots or patterning.

9. Sword Tail

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There are a few different varieties of the swordtail fancy guppy breed. The swordtail breed of the fancy guppy should not be confused with the swordtail fish (Xiphophorus hellerii) which grows much larger.

Double swordtail guppies have both the top and bottom of their tail fins elongated to form a sword shape. They can also be found in top or bottom swordtail forms where only one end of the tail is pointed. The middle section of the tail should not be colored, and this really makes the ‘swords’ stand out.

10. Cobra

Cobra guppies come in a variety of colors, but it is their markings that set them apart. These amazing fancy guppies have a combination of reticulated markings and often have darker vertical bars too. The markings on their tails are often bolder than those on their bodies.

11. Lace

Lace guppies have incredibly intricate markings on their body and fins. They are similar to cobra guppies but lack the vertical bars on their body. Lace guppies are available in various colors, including red, gold, black, and many others.

12. Mosaic Tail

Mosaic tail guppies have amazing markings on their tails and dorsal fins. The markings are similar to those of the lace guppy, only much bolder. The tail coloration of this breed becomes darker and more intense from the start of the fin to the back.

13. Albino

Albino guppies lack pigment, which makes them pinkish-white overall. This makes for a tropical fish that really stands out in the aquarium.

Their eyes are also a pinkish color, which differentiates them from other white guppies. Albino guppies can have some color though, they often show some red, yellow, or blue markings on their bodies and fins.

14. Japanese Blue

Japanese blue guppies (video source) have a metallic dark blue to sky blue color on the tail half of their bodies. The head is often golden or reddish in this breed. The Japanese blue swordtail guppy is a particularly popular tail shape form of this breed.

15. Green

Green guppies are one of the best color schemes if you ask me. They are considered relatively rare, but available in many different patterns and tail shape types.

16. Yellow

Yellow (video source) is a very cheerful color, and a bunch of sunshine-colored guppies can make for a great display. Yellow guppies are available in various breeds including yellow tuxedos, and yellow cobra guppies.

17. Half Black Green

The half-black green guppy has a black back half of its body and a green front. There are many different half-black color combinations, but green is one of the rarest forms.

18. Koi

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A post shared by Pecinta Guppy Indonesia (@koi__guppy)

This fancy guppy fish breed is named after another popular fish. Like their larger namesake, koi guppies usually have a combination of white, red, and black colors.

19. Panda

The panda guppy (video source) is mostly black/blue and white in color. The tail half of the fish tends to be dark while the front half is a silvery color. These fish have dark pectoral fins and dark eyes too.

20. Dragon

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A post shared by Abqary’s Guppy (@abqarysguppy)

Dragon guppies have one of the most dramatic color schemes of all the breeds. These fish are known for their fiery red fins with a half-black guppy body.

21. Dumbo Ear

Dumbo ear guppies (video source) have huge pectoral fins that look almost like the ears of an elephant! Even though their name sounds kind of goofy, these fish take finnage to the extreme and they are incredibly graceful and beautiful to watch.

Other Notable Types

Just in case you’re interested in even more types of guppies, here’s a list of some other popular types that you can look for!

Color types

• Half black purple guppy
• Half black blue guppy
• Half black yellow guppy
• Half black pastel guppy
• Blue guppy
• Red guppy
• black guppy
• Neon blue guppy
• Purple guppy
• Bronze guppy
• Glass guppies

Tail types

• Flag tail guppy
• Fire tail guppy
• Leopard tail guppy
• Grass tail guppy

Keeping and Caring

After looking at all the amazing types of guppies in this article, you might have already chosen a favorite and be thinking of adding them to your collection. Read this section to learn the basics of caring for these fantastic fish!

Tank Setup

Guppies can be kept in a tank as small as 10 gallons. Such a small tank would only be appropriate for a small group of male fish, however.

The last thing you want is for these fish to start breeding and overpopulating a small tank, so I would suggest going up to a 20-gallon or larger if you plan on keeping a mixed group.

Filtration

Adequate filtration is really important for keeping tropical fish healthy, and guppies are no exception. There are many makes and models available, and any type that is rated for your aquarium size or larger will do.

You don’t need the most expensive filter to maintain healthy guppies, but I would recommend running a slightly oversized model. An even better choice is to run two filters. Not only will this provide you with a safety net should one fail, but it will also allow for the increased bioload once your fish begin breeding. A power filter is the best combo of filtration capacity and budget when it comes to guppies.

Heating

Guppies are hardy fish that are comfortable in temperatures down to the lower 70s (Fahrenheit). Pregnant female guppies have been reported to be more susceptible to ich at lower temperatures, however, so maintaining breeding fish at 78-80°F is advised. Using an aquarium heater will make this much easier!

Lighting

Guppies do not have any special lighting needs. Standard fluorescent or LED lighting will suit them just fine. You will only need to look into high-quality lighting if you wish to grow a lot of live plants.

Provide your guppies with a regular light period of 6 to 8 hours a day. Using a timer will make keeping regular timing much easier.

Live Plants

Guppies thrive in planted aquariums and the cover that plants create provides a great place for guppy fry to hang out. Plants are also very useful for increasing oxygen levels and taking up nitrates from the water column.

Although guppies will nip at decaying plant material and eat microorganisms from your plants, they generally do not damage live plants. Guppies prefer hard, alkaline water, so your choice of plants is slightly more limited.

Here are a few easy plants that you can grow in your aquarium:

• Water wisteria
• Java moss
• Java fern
• Amazon frogbit

Decor

Guppies are not fussy when it comes to ornaments and decorations. They are confident and active little fish that do not hide out too much. Choose your decorations based on the style or theme of the aquarium you are putting together, and don’t be afraid to use your creativity!

Remember though, only use aquarium-safe decorations and make sure you wash them carefully before adding them to the tank.

How To Care

Guppies are very easy fish to care for, but there are still some important things you should know before bringing them home. Read on for more information.

Tank Maintenance

Perform a partial water change at least every second week in your guppy tank to keep nitrate levels down. If your tank is heavily stocked, or you’re feeding the tank frequently because you have a lot of fry, you might want to increase this to once or even twice a week. Remember to use a water conditioner if you are using tap water in your aquarium.

The only way to know whether you’re doing enough tank maintenance is to measure your water parameters regularly. Pick up a liquid or strip test kit for this purpose.

Be very careful when performing water changes if you have a lot of fry in the aquarium. I suggest carefully inspecting the water you take out of the tank just in case any fry get sucked up!

Apart from regular water changes, all you really need to do is clean your glass with an algae scraper when necessary and follow the recommended maintenance schedule for your filter.

Important Water Parameters

• Water temperature: 72-80°F
• pH: 7-8
• Hardness: 143 – 536 ppm
• Nitrate: Less than 20 ppm
• Nitrite: 0 ppm
• Ammonia: 0 ppm

Feeding

Guppies are naturally omnivorous and the modern domestic guppy is not fussy about diet at all. A high-quality flake food is a perfect everyday food source for these fish.

For a more balanced diet, I recommend supplementing their diet with an unprocessed food source like bloodworms, daphnia, or brine shrimp. These are available frozen so they are very easy to use. A small amount of these once or twice a week will improve your fish’s health and condition.

Tankmates

One of the best things about guppies is their peaceful nature. They are confident little fish that are always active and visible in the aquarium. They get along great with many other tropical freshwater fish.

The most important factor to consider when picking guppy tankmates is their water parameter compatibility. Guppies thrive in hard, alkaline water, so their tank mates should be comfortable in the same environment.

Let’s take a look at some good guppy tank mates, and some species to avoid.

Good Tankmates

• Mollies
• Swordtails
• Platys
• Dwarf neon rainbowfish
• Least killifish
• Corydoras catfish

Tankmates to Avoid

• Tiger barbs
• Serpae tetras
• Fish that need soft acidic water
• Large cichlids

Health and Disease

Guppies are generally hardy fish, so they are not especially prone to any problems. As a rule, the best way to prevent health issues is to minimize stress. Let’s take a look at some of the best ways to prevent guppy illness:

• Perform regular aquarium maintenance for great water quality
• Avoid overfeeding your fish
• Avoid overstocking your aquarium
• Maintain appropriate water parameters
• Avoid aggressive tank mates

Unfortunately, poor health and disease can happen even when you’re doing everything right. Here are some of the most common guppy health issues to look out for:

• Ich (white spot disease)
• Columnaris (Saddleback/ cotton wool disease)
• Hexamita (Hole in the head)
• Camallanus worm

Breeding

Breeding guppies is extremely easy, so this is a great species to get started with if you’ve never bred tropical fish before. Guppies are livebearers, which means that female guppies give birth to live baby fry. Each female guppy can give birth every month, which means you’re guppy population can grow very quickly!

Female guppies can breed after just 2- 3 months, although it is better to let them grow a little older before they start breeding. Such a short generation time makes guppies an amazing species for breeding projects.

Sexing

Sexing guppies is very easy because adults are sexually dimorphic. This means there are clear physical differences between the sexes that are easy to spot. Let’s take a closer look at some of these guppy sex differences:

• Body size

Overall size is probably the most obvious difference between male and female guppies. Adult females are significantly larger than males.

• Body shape

Female guppies have a much more rounded body shape than males, especially when they are pregnant. Males have a very slender build.

• Finnage

Male guppies have much larger fins in comparison with their body size. Their fins are usually much more heavily patterned and colored too.

The anal fin of male guppies is modified into a structure known as the gonopodium. It is narrow and elongated in comparison to the triangular anal fin of the female.

• Color

Male guppies are much more boldly marked and colorful than females in general.

Pregnant female guppies do have a unique marking that easily identifies them from males, however. Look out for a dark triangular marking on the belly, just in front of the anal fin. This marking is known as the gravid spot and will confirm that the fish is a pregnant female.

• Behavior

Female guppies spend most of their time foraging while males spend a lot of time swimming around the females, trying to get their attention.

Caring for fry

Guppy fry are easy to care for. The fact that they are born live means that you don’t have to worry about egg predation from the other fish in the tank. Unfortunately, adult guppies have no problem eating guppy fry, so it is best to separate them to increase the survival rate of the babies.

Catching all the tiny fry to move them to a separate tank is not going to be easy. Moving a pregnant female over to your fry tank is a much better option! You can go ahead and move the mother fish back into the main tank once she has given birth.

Another great option, which is less stressful on the pregnant female is to add a breeder box to your tank. If you’re not too worried about some of the babies being snacked on, simply growing some floating plants in the tank will provide them with a place to hide out until they are big enough to swim out in the open. I’ve found that water wisteria works great for this, but Java moss will work just as well or even better.

Guppy fry are tiny but hardy little fish. They can be fed the same flake food as the adults, but you’re going to want to crush it up for them. You can use a pepper grinder for this or simply crush the flakes in the palm of your hand.

Preventing Breeding

While breeding guppies may be a fun and fascinating hobby, it is important to have a plan for the fry! The only reliable way to prevent guppies from breeding is to keep only male or only female fish.

Mature females are often already pregnant when you bring them home, so males are a safer bet. When buying female guppies for a breeding project, look for females without very swollen bellies and obvious gravid spots.

Where to Buy

Most local pet stores will sell mutt guppies, and sometimes also a selection of different breeds. For specific breeds, you may need to order online or contact local clubs and breeders.

FAQS

Final Thoughts

I think guppies deserve more appreciation than they get. These fish are the complete package, for all experience levels. The fact that new breeds are still being developed makes this fish even more exciting!

Do you keep guppies? Tell us about your favorite guppy types in the comments below! To learn more about guppy lifespan, check out this article here.

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📘 Want to learn more? This article is part of our complete Freshwater Fish Guide — your ultimate resource for freshwater species, care tips, tank setup, and more.