Author: Mark Valderrama

Table of Contents

• What Most Care Guides Get Wrong About 15 Best Brackish Water Fish (And Common Mislabeling Explained)
• What Are They?
• 15 Best Brackish Water Fish
• Tank Setup
• How To Take Care
• Where To Buy
• FAQS
• Is the 15 Best Brackish Water Fish (And Common Mislabeling Explained) Right for You?
• How the 15 Best Brackish Water Fish (And Common Mislabeling Explained) Compares to Similar Species
• Final Thoughts

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 Most Care Guides Get Wrong About 15 Best Brackish Water Fish (And Common Mislabeling Explained)

The most common mistake I see with 15 best brackish water fish (and common mislabeling explained)s is keeping too few. Guides will say “minimum 6” and leave it at that. In reality, these fish behave completely differently in a proper group of 8 to 10 or more. Keeping just 3 or 4 often leads to stress, hiding, and fin nipping that wouldn’t happen in a larger school. Another thing most guides miss is how much lighting and decor affect this species. 15 Best Brackish Water Fish (And Common Mislabeling Explained)s look washed out under bright white LEDs on a light substrate. Dim the lights, add some tannins, use a dark background, and you’ll see colors you didn’t know they had. I’ve also noticed that many care sheets recommend overly broad water parameters. Yes, 15 best brackish water fish (and common mislabeling explained)s are adaptable.

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

Is the 15 Best Brackish Water Fish (And Common Mislabeling Explained) Right for You?

Before you add a 15 best brackish water fish (and common mislabeling explained) to your tank, it’s worth asking whether this species actually fits your setup and your goals. Here’s a quick breakdown to help you decide.

This species is a good fit if:

• You have a large enough tank to manage territories. Cramped conditions amplify aggression.
• You’re comfortable managing aggression through stocking ratios, line of sight breaks, and tank layout.
• You can commit to regular water changes. These fish produce more waste than many smaller species.
• You’re not planning a peaceful community tank. 15 Best Brackish Water Fish (And Common Mislabeling Explained)s need tank mates that can hold their own.
• You enjoy watching active, interactive fish. Cichlids have personality that smaller species simply don’t match.
• You have backup plans. Sometimes a particular fish just doesn’t work out, and you need a way to rehome it.
• You’re feeding a varied, high-quality diet. Color and health depend on nutrition.

If most of those points line up with your setup, the 15 best brackish water fish (and common mislabeling explained) is worth serious consideration. If several don’t, it’s better to choose a species that matches your tank now rather than trying to make it work.

How the 15 Best Brackish Water Fish (And Common Mislabeling Explained) Compares to Similar Species

Choosing between similar species can be tricky. Here’s how the 15 best brackish water fish (and common mislabeling explained) stacks up against some common alternatives.

The 15 best brackish water fish (and common mislabeling explained) occupies a specific niche in the aquarium hobby, and direct comparisons really depend on what you’re looking for. In my experience, the most common question people ask is whether they should choose the 15 best brackish water fish (and common mislabeling explained) or something similar that’s more widely available. The answer usually comes down to three things: tank size, water parameters, and what other fish you’re keeping. If your setup matches what the 15 best brackish water fish (and common mislabeling explained) needs, it’s hard to beat. If not, there are usually alternatives worth exploring.

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 breed constantly, eat their young, and will overpopulate any tank without predation or sex separation. The appeal is obvious. The population explosion that follows is the part nobody warns you about.

If you keep males and females together, you are breeding livebearers. There is no opt-out.

If you keep males and females together, you are breeding livebearers. There is no opt-out.

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 is 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 is 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 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 is 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 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 is 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 is 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 is 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 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 is kept on either a sand or gravel substrate. These fish do not 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 is 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, is pushed around by an overly strong water current, though. A power filter 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 is 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 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 is 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 is kept with most livebearers. They are the ideal tank mate in regards to temperament, space requirements, and color, and is 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 is 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 with caution, with them being more successful with Endler’s livebearers due to their speed.

Tank Mates To Avoid

Red Devil Cichlid Amphilophus labiatus” class=”wp-image-545169″/>

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 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 is removed from the aquarium to ensure survival and to prevent inbreeding. They is 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

Glowlight Danio Near Gravel” class=”wp-image-557066″/>

• 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

Giant Danio Fish in Aquarium” class=”wp-image-557080″/>

• 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.

Fancy guppies from pet stores are genetically fragile. Decades of inbreeding for color have produced fish that die from diseases wild guppies shrug off. The gap between a well-bred guppy and a mass-produced one is the difference between a fish that thrives for years and one that dies in weeks.

Where you buy your guppies matters more than how you keep them.

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 is 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 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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This fancy guppy fish breed is named after another popular fish. Like their larger namesake, koi guppies 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 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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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 is 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 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 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 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 is 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 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.

Freshwater eels escape from tanks. Every single species. They find gaps you did not know existed and end up on the floor.

Eels treat every crack in your lid as an exit. Seal them all.

Freshwater eels are one of those categories where the label is misleading. Most of what gets sold as a “freshwater eel” is actually a spiny eel from the family Mastacembelidae (fire eels, tire track eels, peacock eels), which aren’t true eels at all. That’s not a knock on them; they’re fascinating fish with real personality. But it’s worth knowing what you’re actually buying. A few things apply across the whole group: they’re escape artists that need a tightly sealed lid, they’re mostly carnivores, and many get significantly larger than people expect. After 25 years in the hobby, these are the 11 types I’d point someone toward if they want to add an eel-like fish to their tank.

What are Freshwater Eels?

The freshwater eels are nocturnal eels, meaning they prey at night with their rather weak eyesight but an incredible sense of smell. Freshwater eels are catadromous, living their entire lives in freshwater and migrating downstream to spawn in the ocean.

True freshwater eels belong to the family Anguillidae and the genus Anguilla. Around 15 to 20 freshwater species of eels fall into the Anguilla genus, including the very popular American eels, Moray eels, Spaghetti eels, and European eels. Unlike other types of eels, Anguillidae freshwater eels have scales on their body and they are a crucial source of food in some parts of the world, especially in Europe where they’re bred on farms at large scales.

Very few species of freshwater aquarium eels acquire the aquarium hobby. Among them, the most popular is from the genus Mastacembelidae, classified as spiny eels, such as the tire track eel and fire eel.

Some Fun Facts About Freshwater Eels

Here are some fun and bizarre facts about freshwater aquarium eels.

An Eel is just elongated versions of fish

It would surprise you, but many years ago, people confused eels with snakes, because of their uncanny resemblance. However, according to their anatomy, they are just an elongated version of fish.

However, eels differ from fish in a number of ways, including the absence of pelvic fins and lack of pectoral fins in some eels. Also, the dorsal fins and anal of eels are merged with the tail, forming a single strip running along with most of the eels’ length.

Ardent Swimmers

Freshwater eel species are bottom. They prefer holes, the bottom layer of your tank, and other hidden places to bury themselves in the substrate. They love to dig deeper in the dirt and plants to take full advantage to surprise their prey with occasional attacks.

Below 41°, Eels Go Torpor

During extreme winters, when the temperature reaches below 41°F or 5°C, freshwater eel species dip themselves in the mud and enter into a stage, similar to hibernation, known as torpor.

Diverse

According to research, there are approximately 800 species of eel. 110 genera, 19 families, and four suborders that we term eels.

Favorite Treat

Some cultures such as Japanese, Korean, and Chinese feast on eels. Interesting enough?

That’s Not All.

These cultures identify eels as a popular cuisine and it costs way more expensive. In Hong Kong, only a kilogram of eels would cost you around 1000 HKD. That’s because eels are known to boost stamina and energy levels, especially some species of eel, including European eels, jellied eels, longfin eels, etc.

They Could Easily Kill You

Have you ever wondered why eel is always served cooked?

That’s because the blood of eel is highly poisonous and it will kill you. The blood of eels contains a toxic protein that can cramp your body muscles, including the heart, leading to sudden death.

They Can Swim Backward

The body of the eel is attenuate shaped, starting with a long, slimy body that ends with a powerful tail. Therefore, their body shape allows freshwater eels to wiggle and swim backward after their prey.

No One Knows How They Reproduce

Humans for hundreds of years have tried to figure out how eels “do it”. Want to learn more? Check out this article!

11 Best Freshwater Varieties to keep as Pets

Now that freshwater aquarium eels have got all your attention, it’s time to dig a little more about the top 12 types of eels you can keep as pets. We have a video below from our YouTube Channel. If you like our content, be sure to subscribe as we post new videos every week! We will go into more detail in the blog post below.

Let’s revamp your aquarium with my top recommendations.

1. Freshwater Moray

• Scientific Name: Muraenidae
• Difficulty Level: Moderate
• Temperament: Shy and semi-aggressive fish
• Adult Size: 6. 150 inches in length (7.6. 400 cm)
• Minimum Tank Size: at least 15-30 gallon tank
• Diet: Carnivore, Prefer live food, such as brine shrimp, earthworms
• Origin: Tropical and Temperate Waters
• Temperature: 24. 28°C / 75. 82°F
• pH: 7.0 to 9.0
• Difficulty to breed: Almost impossible in a tank
• Planted tank suitability: Possible

If I would have to name one risky freshwater aquarium eel, it has to be the freshwater moray eel (video source). Not because they are a difficult or aggressive fish, but due to their finicky nature. Moray eels are easily stressed if not provided with the right environment. Therefore, if you’re a busy fishkeeper or a novice, I suggest you look out for other options.

Habitat and Water Conditions

The origin of freshwater moray eels stems from the saltwater of tropical and subtropical regions, where there are coral reefs in abundance. Freshwater morays are secretive in nature and prefer hiding in the rocks.

Most of moray eels live in saltwater environments. However, some are found in brackish water and certain species of eel are found in freshwaters. That being said, Moray eels is quite sensitive to freshwaters. Therefore, extensive experience is required to keep them as pets.

Appearance

Your first impression of Moray eels would be a scary one. With their snake-like appearance and a long, slender body with the absence of pectoral fins, patterned bodies, and sharp teeth, the first look of Moray eels is no good.

However, it’s still a popular choice of aquarium fish among many enthusiastic aquarists because of their behavior.

Behavior

Hobbyists adore freshwater moray eels for their peculiar behaviors such as team hunting, adaptability, snake-like swimming capability, and sneaky nature that provide an outstanding spectacle in your aquarium.

I understand it is overwhelming to keep a moray eel in your home aquarium considering their size and extra demanding nature, but they are an absolute treat for your display tanks once their basic needs are met.

2. Fire

• Scientific Name: Mastacembelus erythrotaenia
• Difficulty Level: Moderate
• Temperament: Semi-aggressive fish
• Adult Size: 20 inches (60.8 cm)
• Minimum Tank Size: at least 80 gallons
• Diet: Carnivore
• Origin: Southeast Asia
• Temperature: 75-82° F
• pH: 6.8-7.2
• Difficulty to breed: Difficult
• Planted tank suitability: Possible with floating plants

Although not true eels, fire eels make a beautiful freshwater aquarium fish that you cannot resist. With over 20 inches in length, the fire eel is a distinctive yet huge breed that requires maximum space in your aquariums.

Origin

The fire eel is native to South Asia. They are found in the lowland rivers of Vietnam, Thailand, Myanmar, and Sumatra.

Appearance

The fire eels range from dark gray to dull black in color with striking red and yellow horizontal stripes, extending from the head to the tail. The markings on the eel are like that of fire flames painted on a hot rod. Hence, the name.

Adult Size

In the wild, the size of fire eels is much bigger than in captivity. And so, you can expect a fire eel to reach a length of around 3 feet or longer. However, in captivity, they can get about 20 inches long, making them the largest species of spiny eels in the aquarium world.

Due to their big size, they need a bigger space with at least a 55-gallon tank size and water temperature should be around 76°F with a neutral pH.

Behavior

Fire eels are shy and prefer to stay aloof most of the time. They are also bottom dwellers, burrowing in the sand. To cater to this behavior, I suggest using sand as a substrate in your aquarium so that they don’t harm their slender bodies.

Also, like most freshwater aquarium eels, these eels are nocturnal, meaning they are the most active during nighttime. However, you can train your interesting pets to come out during the day to feed and hunt.

A fire eel likes to feed and swim around during the night. If you keep the room and tank dimly lit, your pet fire eel might come out more often during the day.

As far as the plants are concerned, these types of eels are messy and voracious eaters. Therefore rooted plants are not suitable for their tank. Hence, keep floating plants to keep them happy.

Tankmates

Fire eel is a particularly peaceful fish that remain content in its provided space. However, eels, by nature are predatory creatures, and so your fire eel is dangerous to other smaller freshwater fish. The best tank mates for your eels are:

1. Angelfish
2. Medium-to-large Barbs
3. Green terror
4. Oscar fish

Nutrition

Fire eels, in their natural habitat munch on live food that is accessible to them. Be it small crabs, brine shrimp, insects, snails, or worms. In captivity, things are no different. These eels enjoy live food, including bloodworms, small fish, mussels, live shrimp, and tubifex.

3. Peacock Eel

• Scientific Name: Macrognathus siamensis
• Difficulty Level: Moderate
• Temperament: Peaceful
• Adult Size: 11.8 inches (29.97 cm)
• Minimum Tank Size: at least 35 gallons
• Diet: Carnivore
• Origin:Southeast Asia
• Temperature: 73.0 to 82.0° F
• pH: 6.0-8.0
• Difficulty to breed: difficult to breed
• Planted tank suitability: Possible with floating plants

If you’re low on space, peacock eels are just for you!

Many fish stores stock peacock eels because of their increasing demand. However, if you don’t happen to find one, fret not. A peacock eel goes by many names, including striped peacock eel, Siamese spiny eel, and spot-finned spiny eels.

Origin

The peacock eels originate from slow-flowing, stagnant bodies of water in Southeast Asia, mainly in India, Sri Lanka, Thailand, Sumatra, and Malaysia. However, they are commonly found in the Mekong, Chao Phraya, and Maeklong river basins. Their native environment allows them to enjoy plant and animal life in abundance. Hence, peacock eels are quite manageable, if their basic needs are met.

Appearance

Like other eel species, the peacock eels possess an elongated body with a dark brown back and light brown flanks. As compared to the entire body, the stomach of this spiny eel is much lighter. From the snout to the caudal fin, peacock eels showcase a fine yellow line that looks adds to their grace. The dorsal and caudal fins of the peacock eels feature five eyespots.

Depending on the nature of their environment, they can grow around 15 centimeters (6 inches) in captivity. However, in their natural habitat, peacock eels can grow up t0 12 inches in length (30 cm long).

Tank Setup

These small eel-like fish should be housed in an aquarium of around 21 inches in length and a 20-gallon tank. But when they grow bigger, shift them to a bigger aquarium with a capacity of around 40 gallons or more.

Peacock eels are brackish freshwater aquarium eels that prefer some salt in their aquarium. Therefore, I recommend adding one teaspoon of aquarium salt per gallon of water to the fish tank.

Behavior

Peacock eels are like your introverted friends that take some time before getting all comfy. Therefore, at first, your eel-like fish might feel distant and aloof, but over time, when their environment is well-suited, they will become very friendly.

The native environment of peacock eels is densely populated with plants. Therefore, an aquarium with plenty of plants, PVC pipes, and hidden or sheltered spots created by rocks and woods is recommended to keep this eel-like fish happy.

Food

Peacock eels are highly selective and moody when it comes to food. There are days when this small fish would take anything and days when nothing pleases it. However, these fish species are nocturnal and forage for food at night. Their favorite diet includes worms, larvae, live brine shrimp, blood worms, and mosquito larvae.

Tankmates

Peacock eels are calm creatures that mind their own business, provided the tank mates are not smaller fish that is mistaken for food.

The compatible tank mates for peacock eels are:

1. Hatchetfish
2. Rainbowfish
3. Larger Rasboras
4. Swordtail Fish

4. Starry Night

• Scientific Name: Mastacembelus frenatus
• Difficulty Level: Moderate
• Temperament: Semi-aggressive fish
• Adult Size: at least 15 inches in length
• Minimum Tank Size: at least 60 gallons
• Diet: Carnivore, feeds on insects, small fish, and crustaceans in the wild. Will accept frozen foods
• Origin: Wild Central Africa
• Temperature: 76-82° F
• pH:  6.8 . 7.8
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

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If you’re looking for a small, hardy fish, the African starry night eel is your go-to pet for home aquariums.

Origin

These freshwater aquarium eels are found in Central Africa, ranging from the Congo River basin to various Rift lakes in the surrounding regions, including the flowing rivers of Tanzania.

Behavior

Unlike other freshwater aquarium eels, the starry night eel is hardy and extroverted in nature, making a graceful appearance in your tanks every now and then. However, like most spiny eel species, starry nights are slow eaters. Thus, always ensure the amount of food they get is sufficient to meet their needs. In the wild, they like to munch on small fish, plant matter, and aquatic invertebrates. However, in captivity, starry night eels readily accept meaty food such as frozen krill, nightcrawlers, and frozen bloodworms.

Appearance

The starry night eels are small to medium-sized fish that grow up to 15 inches in length and possess a variable color pattern. The most common color of starry night eels is brown with a variable blotched pattern.

Tank Setup

These freshwater aquarium eels thrive in water temperatures of around 73°F to 80°F, a pH of 7.8 to 8.4, and a hardness of 7 to 30°H.

The tank capacity should be at least 30 gallons or larger to accommodate a juvenile starry night eel happily. A larger tank around 55 to 75 gallons is optimum for these eels like fish. Furthermore, the tank should be well-planted with high-quality sand substrate, and lots of hiding places. For example driftwood, rock caves, and PVC pipes.

The tank should be dimly lit and the water flow should be sluggish to motivate these bottom dwellers to venture out of their caves. Most importantly, a tight-fitting lid should be installed to avoid accidents.

Tankmates

Starry night eels make a very peaceful community, so they get along with other fish really well. However, the size of the fish should be taken into consideration. For starry night eels, larger fish make great tank mates.

1. Rainbowfish
2. Peaceful cichlids
3. Large peaceful catfish

5. Tire Track

• Scientific Name: Mastacembelus armatus
• Difficulty Level: Moderate
• Temperament: Semi-aggressive fish
• Adult Size: at least 30 inches in length
• Minimum Tank Size: at least 125 gallons
• Diet: Carnivore, Predator, feeds on insects, fish, and crustaceans in the wild. Will accept frozen foods but is finicky at first.
• Origin: Wild Thailand
• Temperature: 76-82° F
• pH:  7.0 . 8.2
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

Before getting your hands on the tire track eel, beware; these eel-like fish can get ginormous. (up to 30 inches in length)

Origin

The tire track eel are a popular species of eel that are found in river systems throughout most South Asian regions, such as Java and Sumatra in Indonesia. They originate from shallow, slow-moving waters, including rivers, South Asian swamp, and flooded forests.

Appearance

These freshwater aquarium eels are close cousins of Zig zag eels that are also from Asia. They are quite identical because of their distinct, irregular dark black markings. Therefore, the common name of tire track eel is derived from its distinctive color pattern on either side of the eel that resembles the tire.

Behavior

These eel-like fish are semi-aggressive but very personable and intelligent that recognize their owners well. They feed on live food, such as earthworms and frozen foods. Since they double in size in a short time period, it is recommended to keep them with large tank mates.

6. Yellow Tail Spiny

• Scientific Name: Macrognathus pancalus
• Difficulty Level: Moderate
• Temperament: Semi-aggressive fish
• Adult Size: at least 7.1 inches in length, 18 cm
• Minimum Tank Size: at least 125 gallons
• Diet: Carnivore, Predator, feeds on insects, fish, and crustaceans in the wild. Will accept frozen foods but is finicky at first
• Origin: Bangladesh, India, Nepal, and Pakistan
• Temperature: 73-81° F
• pH: 7.0-8.5
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

If you want to keep tankmates with your eels, your search ends at yellowtail spiny eel. Only the smallest creatures can fit in the mouths of yellowtail eel, such as ornamental freshwater shrimp. Therefore, they make great community tank fish.

Originating from the heavily vegetated canals, ponds, and sluggish streams of rivers, these freshwater aquarium eels bring peace and tranquility to your tanks.

They grow only six to seven inches in length and feed on live food, such as worms, frozen, and freeze-dried food. They are very shy at first, but once they get a hold of the environment, they get comfortable and personable with their owners and tankmates.

The tank of these eel-like fish should have sand substrate so they can dig and bury themselves in the hiding places. Hence, adding secretive places such as rocky caves, PVC pipes, and driftwood is highly recommended.

7. Half Banded Spiny

• Scientific Name: Macrognathus circumcinctus
• Difficulty Level: Moderately difficult
• Temperament: Semi-aggressive fish
• Adult Size: at least 7.9 inches (19.99 cm)
• Minimum Tank Size: at least 35 gallons
• Diet: Carnivore
• Origin: Asia, Mekong and Chao Phraya basins, southeastern Thailand, Malay Peninsula, Sumatra, and Indonesia
• Temperature: 75.0 to 82.0° F
• pH:  6.0 . 7.0
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

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Half-banded spiny eels (video source) are found in Asia, particularly in Mekong, Chao Phraya, Thailand, Malay, Sumatra, and Indonesia. Other common names of these species are Belted spiny eels or Large eels.

Like most eels, their bodies are elongated with a pointed snout and the dorsal and anal fins extend back to the very small caudal fin. Half-banded spiny eel grows around 8 inches and can fit in a medium-sized aquarium with a lifespan of over 5-10 years. In some rare cases, half-banded eels live up to 15 years and longer, if taken care of.

8. Senegalus

• Scientific Name: Polypterus senegalus
• Difficulty Level: Moderate
• Temperament: Semi-aggressive fish
• Adult Size: at least 20 inches in length
• Minimum Tank Size: at least 90 gallons
• Diet: Carnivore
• Origin: African countries, including the major Nile River system; these countries include Egypt, Kenya, Nigeria, and Senegal
• Temperature: 75-82° F
• pH:  6.2 – 7.8
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

The Polypterus eels (video source), commonly called Reed fish, Dinasaur eels, Bichir, or swamp eels originate from heavily vegetated water systems in Africa and India. They are very common in the native lands that they are mostly found in ditches.

The Polypterus senegalus eels have jagged dorsal fins, protruding nostrils, and pointed teeth, it’s no wonder why they’re called the swamp dragon.

The most interesting trait of Polypterus eels is their ability to stay out of water for some time because of their primitive lungs and swim bladder.

Therefore, if you want your share of prehistoric dinosaur that is both hardy and interesting, the Polypterus eels would make great pets for you.

9. Bichir

• Scientific Name: Polypteridae
• Difficulty Level: Moderate
• Temperament: Calm
• Adult Size: at least 9.8 inches in length
• Minimum Tank Size: at least 50 gallons
• Diet: Carnivore
• Origin: Freshwater basins in Africa and India
• Temperature: 75.2-78.8 °F
• pH:  6.5 – 8.0
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

Bichirs are not true eels, instead, they are a family of freshwater ray-finned fishes that resemble eels so much. Bichirs are popular, fancy aquarium fishes inhabiting our planet for a very long time. They are found in the freshwater basins of Africa and India, where the water is muddy and silted bottom. Bichirs have a poor sense of sight but they can navigate freely in brackish waters due to their excellent sense of smell.

The maximum length of Bichirs in the wild is around 39 inches. However, in captivity, they are much smaller fish, measuring around 9.8 inches.

The body of Bichirs is covered with flexible scales that look like diamonds. The skin is very strong, protecting the fish from predators. Also, if the skin remains moist, Bichirs can stay out of water for quite some time.

Bichirs are hardy fish with leg like appendages that doesn’t demand any attention and care. They can even live in dirty water. Therefore, the only difficulty while keeping them in home aquariums is their ability to prey. To cater to this, always place them with tank mates larger than Bichirs, and you’re good to go.

10. African Ropefish (Erpetoichthys Calabaricus)

• Scientific Name: Erpetoichthys calabaricus
• Difficulty Level: Easy
• Temperament: Peaceful
• Adult Size: at least 15 inches in length
• Minimum Tank Size: at least 45 gallons
• Diet: Carnivore
• Origin: Western Africa, Congo, Angola, Nigeria, Cameroon, Equatorial Guinea, Benin.
• Temperature: 76-82° F
• pH:  7.0 . 7.6
• Difficulty to breed: Difficult
• Planted tank suitability: Possible

African Ropefish (video from Fluval Aquatics) is a stunning eel-like fish found in Western Africa and collected in the Democratic Republic of Congo, Angola, Nigeria, Cameroon, Equatorial Guinea, and Benin.

It lives in shallow, densely vegetated waters. Therefore, it is recommended to set up an aquarium with aquatic plants and a soft substrate with pieces of driftwood to form hiding places for your African ropefish.

African ropefish are not territorial. Therefore, a peaceful community fish that gets along with fish larger than their size, including Synodontis species, larger characins, and cichlids such as Severum, Angelfish, some Tilapia species, etc.

11. Snowflake (Indian Mud Moray Eel)

• Scientific Name: Echidna nebulosa
• Difficulty Level: Easy
• Temperament: Semi-Aggressive fish
• Adult Size: at least 23.6 inches in length
• Minimum Tank Size: at least 30 gallons
• Diet: Carnivore
• Origin: Coastal Indo-west-Pacific: Andaman Islands, Bangladesh, Hawaii, India, Indonesia, Malaysia, Philippines, Singapore, and Sri Lanka.
• Temperature: 75-82° F
• pH:  7.5 – 8.5
• Difficulty to breed: Difficult
• Planted tank suitability: Possible with caution

The freshwater snowflake eel is often confused with Echidna Nebulosa (Fully marine eel, colloquially known as Snowflake Moray).

Snowflakes eels (image source from webwetmedia) are found across coastal regions of the Indo-West-Pacific, starting from India to the Philippines, and then to Indonesia.

These nocturnal predators are found in muddy brackish estuaries and marine waters, only migrating into freshwater to spawn. Unfortunately, because this species is sometimes found in freshwater during the breeding season, it has been marketed erroneously in the trade for many years as the “Freshwater Moray Eel”, when actually it requires brackish or full marine conditions long-term, as it’s visits to freshwaters are only very temporary.

This large bottom-dweller requires a spacious aquarium with a soft sand substrate in which it can forage about for food and wallow. There should be a multitude of hiding places amongst rocky caves, pvc tubes, and salt-tolerant plants. Filtration should be efficient with areas of moderate water movement, and some quieter resting areas out of the current. Frequent partial water changes are essential to keep nitrate to a minimum.

Be sure to use a quality marine salt for water changes, and monitor salinity carefully with a hydrometer. Indian Mud Moray Eels are highly predatory, feeding on fish (even fairly large ones) in the wild. However, they may be kept in groups of their own kind in spacious aquaria, if all specimens are of roughly the same size, are added simultaneously, and are provided with at least one shelter each. We do not recommend housing with other fish species, as the eels will strike at them and most will soon be eaten.

Although their eyesight is rather poor, Indian Mud Moray eels have a keen sense of smell and can detect movement vibrations very well, quickly lunging at any potential prey. This includes the hands, so much care should be taken when carrying out maintenance on the aquarium – they are capable of giving a nasty bite! As with other moray eels, these fish have needle-like teeth and possess a second set of teeth in the throat, known as the pharyngeal jaws which assist in capturing and swallowing prey.

Although this species is not highly venomous, it does have a mildly toxic mucus coating to the mouth which can cause skin irritation if bitten. Ensure that the tank has tight fitting covers as these fish are accomplished escape artists, which can lead to their deaths. Kept under ideal conditions, the Indian Mud Moray Eel has been known to live in excess of 30 years; they will not survive for long in pure freshwater.

FAQs

Final Thoughts

Freshwater aquarium eels are beautiful creatures to adorn your home aquariums. Coming from freshwater rivers of South Asian regions, they are mostly peaceful and get along pretty well with tankmates of their own sizes. However, due to their finicky nature, freshwater aquarium eels might not be a great fit for novice fish keepers.

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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.