15+ Types Of Blennies (That You Can Keep In Your Tank)

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Ask any saltwater hobbyist and you’ll find that one of their favorite fish belongs to the blenny family. Marine blennies are small yet full of personality and color that bring excitement to the lower portions of any reef tank. Not only are these fish the perfect size for any aquarium setup, but they are perfectly happy with almost any species of reef fish. They’re fun and easy to keep and might even clean up some nuisance algae along the way.

Here are some of the best and most popular types of blennies available for the saltwater aquarium and how to take care of them!

Takeaways

  • Blennies are some of the most popular marine aquarium fish due to their hardiness, personalities, and colors as well as their compatibility with tank mates and invertebrates.
  • Some popular choices include the Tail Spot, Lawnmower, Midas, and Stripped blennies
  • Some blennies have been known to pick at corals, so it’s important to choose the right species for your tank.
  • Other blennies are proficient algae eaters and can clear a tank of nuisance algae, like hair algae.
  • Blennies come in all shapes and sizes and are kept in pico, nano, or full reef setups.

Introduction

Blennies are some of the most popular fish available in the saltwater aquarium hobby. These fish usually stay under 5 inches long, have a peaceful demeanor, and are reef safe. This makes them perfect for pico, nano, and full sized setups. All species require at least 10 gallons.

These fish are enormously varied in coloration, with some being bright yellow and others being pitch black. They are easily recognizable by their slender bodies and short faces with whisker-like appendages. These marine aquarium fish groups are even more identifiable by their unique behavior, including using their pectoral fins to perch on rocks and glide between crevices. These fish are full of personality as they hop from one rock to the next, watching as the world turns around them.

It’s also something to note that many blennies do not actually have a swim bladder. These blennies exhibit a rock skipper type of behavior, which means rockwork important to have as pat of the tank.

Some species of blenny excel at eating algae and can be used to control growth as long as dietary needs are met in the long term. On the other hand, there are more carnivorous species that require additional protein on top of a plant based diet. Regardless, these fish are hardy and adaptive and will readily accept most live, frozen, and freeze-dried foods.

Types Of Blennies

With so many different types of blenny available in the aquarium trade, there is a species that’s right for everyone! Just keep in mind that most blennies do not get along with each other or with similar-looking fish, so it’s generally best to keep one blenny per tank unless the system is especially large.

1. Lawnmower

  • Scientific Name: Salarias fasciatus
  • Adult Size: 4-5 inches
  • Origin: Indo Pacific
  • Tank Size: 30 gallons

The lawnmower blenny isn’t the most colorful marine aquarium fish species, but these nano-sized bottom-dwellers are easy to keep in a community tank setup.

Also known as for it’s more common name the algae blenny or sailfin blenny, lawnmower blennies are a popular addition to aquariums struggling with algae problems. While eager herbivores, the aptly named lawnmower blenny can be picky about what kind of algae they eat. This can be frustrating to hobbyists looking to eradicate a hair algae problem and their blenny completely ignores it. It should be said that these preferences are largely based on an individual scale.

The lawnmower blenny originates from the Indo-Pacific and can be found around reef ecosystems. They are often found alone but may form pairs in the wild. In the aquarium setting, they are generally aggressive towards their own species but are completely safe with other reef species.

2. Tail Spot

Tailspot-Blenny
  • Scientific Name: Ecsenius stigmatura
  • Size: 2-3 inches
  • Origin: Western Pacific Ocean
  • Tank Size: 10 gallons

The tail spot blenny is one of the most popular species for the nano aquarium under 40 gallons. These fish stay relatively small and have a beautiful orange-brown coloration that other species can’t offer. The tail spot blenny is obviously named after its small black and white-outlined spot at the base of its tail fin.

In the aquarium, tail spot blennies offer a burst of personality, which makes them easy to pair with other community saltwater species. However, these fish may become shy if kept with overly active or aggressive fish.

These fish are labeled as herbivores but rely on small crustaceans and invertebrates for some protein as well. They are not generally considered algae eaters but may pick at some film algae and other tufts of longer algae that may be present.

Tail spot blennies originate from the Western Pacific Ocean, along the coasts of the Philippines and Indonesia. There, they are found in sheltered reefs, sometimes in small groups.

3. Bicolor

Bicolor-Blenny
  • Scientific Name: Ecsenius bicolor
  • Size: 4 inches
  • Origin: Indo-Pacific
  • Tank Size: 30 gallons

Similar to the tail spot blenny in personality and color, the bicolor blenny is another popular choice of blenny for reef tanks. These fish are half grey and half orange, which makes them camouflage among the rocks when facing forward and provide a splash of color once they turn away.

The bicolor blenny is slightly larger than the tail spot blenny and needs a larger tank of 30 gallons or more. It should also be said that these fish have been known to nip at corals, especially if not provided with an adequate diet. Though this may be the result of mistaken identity of algae or messy eating of other food, some blennies might just have an appetite for corals. In general, though, these fish are perfectly reef-safe.

Bicolor blennies originate from reef systems throughout the Indo-Pacific. They form distinct mating pairs in their natural habitat but can become aggressive towards similar-looking fish in the home aquarium.

4. Midas

Midas-Blenny
  • Scientific Name: Ecsenius midas
  • Size: 4-6 inches
  • Origin: Indo-Pacific
  • Tank Size: 30 gallons

Another fan favorite, the Midas blenny is named after its bright gold appearance. These are one of the most boldly colored blenny species available. They also have a slight eel-like appearance, especially when they swim.

Unlike the previous blenny species on this list, Midas blennies are omnivores that need a healthy balance between available algae and supplemented protein-based foods. These marine fish are also one of the larger aquarium blennies available, growing to be 6 inches long. While relatively long fish, Mids blennies claim a rock territory and tend to stick with it. They can become aggressive towards other fish that might try to invade their territory, especially in smaller tanks.

The Midas blenny originates from a variety of reef ecosystems throughout the Indo-Pacific. Interestingly, these fish can be found living alongside other similar-looking species and may even change appearance when moving through the water column.

5. Striped

Stripped-Blenny
  • Scientific Name: Meiacanthus grammistes
  • Size: 5 inches
  • Origin: Western Pacific Ocean
  • Tank Size: 30 gallons

Also known as the striped fang blenny, striped blennies are venomous blennies that can be safely kept in the home aquarium.

These are very interesting fish that are generally harmless unless provoked. Striped fang blennies have fangs along with venom glands that are used to attack predators. This venom causes the predator to relax and release the fish. This unique venom is currently being studied for medical value.

Otherwise, the striped blenny is a colorful fish with black and white alternating stripes and a faint yellow head. They live throughout the Western Pacific Ocean in schools, though they are mostly kept solitary in the aquarium setting.

6. Orange Spotted

Orange-Spot-Blenny
  • Scientific Name: Blenniella chrysospilos
  • Size: 5 inches
  • Origin: Indo-Pacific
  • Tank Size: 30 gallons

Also known as the red spotted blenny fish, the orange spotted blenny is named after its white and orange-red mottled color. While this might seem like a high-end blenny due to its bright coloration, orange spotted blennies are widely available and affordable. They’re also very hardy and adapt well to full reef setups (image source).

While a herbivorous species, the orange spotted blenny has been seen picking at some corals from time to time. Like other blennies, this may be an accident or on purpose, and appetite will vary from one fish to the next.

Orange spotted blennies originate from the Indo-Pacific and feed on coral reefs covered with microalgae. Most often, these fish will claim a hole in their rockwork as their territory and live peacefully with other fish as long as they stay out of their space.

7. Scooter

Scooter-Blenny
  • Scientific Name: Synchiropus ocellatus
  • Size: 3-5 inches
  • Origin: Pacific Ocean
  • Tank Size: 30 gallons

Though these fish are commonly known as scooter blennies, they are actually not true blennies and belong to the Callionymidae family instead. These fish are often seen alongside the red scooter blenny (Synchiropus stellatus) and green mandarin (Synchiropus splendidus).

In recent years, marine hobbyists have fought to inform novice aquarists about the true care requirements these fish need. Unfortunately, scooter blennies and mandarins are often showcased alongside easy and hardy fish, which makes hobbyists believe that they are also easy to keep. They are also relatively inexpensive, which makes them more appealing.

The truth is that scooter blennies are very difficult to keep for even the most experienced marine aquarist. These fish require a near-constant supply of copepods and other small invertebrates that they can pick at. In fact, they are named scooter blennies because of the stop-and-go motion they display while hunting for food along the substrate and rockwork.

To successfully keep a scooter blenny in the saltwater aquarium, the tank must be fully mature and copepods must be farmed. Otherwise, these fish will slowly starve to death.

8. Starry

Starry-Blenny
  • Scientific Name: Salarias ramosus
  • Size: 5-6 inches
  • Origin: Western Central Pacific Ocean
  • Tank Size: 30 gallons

The starry blenny, also known as the snowflake blenny, is a beautiful species of blenny that is easy to find and easy to keep. These fish have a reddish-brown base color that is spotted with tiny white dots that earn them their name.

These fish are very similar in behavior to the lawnmower blenny and will hop from one rock to the next searching for food. They are mainly herbivorous and get a good amount of their nutrition from the algal films that are already growing in the tank. However, starry blennies will readily accept other common live and frozen foods.

The starry blenny is native to the Western Central Pacific Ocean. They are found in groups in protected reefs and estuaries but do best as one of the only bottom-dwellers in an aquarium setup.

9. Smith’s

  • Scientific Name: Meiacanthus smithii
  • Size: 3 inches
  • Origin: Indo-West Pacific
  • Tank Size: 10 gallons

The life of the party, the Smith’s blenny (video source), also known as the disco blenny, is a small fish that can fit in many reef tank setups. These fish are yellowish-silver with a black stripe that runs along their dorsal fin. Like others in the Meiacanthus taxonomic group, the Smith’s blenny has venomous fangs that it can use to escape predators.

Smith’s blennies do well in a minimum tank size of 10 gallons as long as there is plenty of live rock for them to hide. Otherwise, they will need at least 30 gallons or more.

10. Harptail

  • Scientific Name: Meiacanthus mossambicus
  • Size: 3-4 inches
  • Origin: Western Indian Ocean
  • Tank Size: 30 gallons

Harptails, also known as the Mozambique fangblenny (video from the Basement Reef), are venomous blennies originating from the eastern coast of Africa. They are found on small coral reefs that feature more live rock than coral. These fish use their venom to bite the mouths of other fish if ingested. The predator will then hopefully release the blenny, unharmed.

Not much is known about the natural behavior of harptail blennies, but they are a good tank mate choice for reef aquariums with minimal invertebrates. While these fish mainly stay in tiny nooks in the rockwork, they will move through the tank looking to eat small crustaceans and other micro food. Harptail blennies are omnivores, but they are more likely to accept brine shrimp and mysis shrimp than blanched vegetables.

11. Canary

  • Scientific Name: Meiacanthus oualanensis
  • Size: 5 inches
  • Origin: Western Central Pacific Ocean
  • Tank Size: 30 gallons

The blenny with the brightest color, the canary blenny is a beautiful deep orangey-yellow. Another Meiacanthus spp., the canary blenny has venomous fangs that it can use to escape the mouths of predators. It should be noted that canary blennies can become aggressive fish if kept with other similar-looking species, like the Midas blenny.

Canary blennies (video source) originate from the Western Central Pacific Ocean, specifically around the coasts of Fiji. They are omnivores and will appreciate a balanced diet of plant- and meat-based foods. High-quality food, like vitamin-enriched brine shrimp, will help increase your blenny’s already vibrant colors.

12. Blackline

  • Scientific Name: Meiacanthus nigrolineatus
  • Size: 3 inches
  • Origin: Western Indian Ocean
  • Tank Size: 10 gallons

The backline goby is named after its dark, black line that cuts across the dorsal of the fish. The front of the head is greyish-blue and the tail is pale yellow. This is a smaller species of blenny and can comfortably be kept in a 10 gallon size tank as long as there are plenty of hiding spots. Blackline blennies are reliably reef-safe and are unlikely to pick at present invertebrates.

These fish are native to the Western Indian Ocean, namely in the Red Sea and the Gulf of Aden. They are a type of fang blenny and are capable of delivering a venomous bite.

13. Black Sailfin

Brown coral blenny (Atrosalarias fuscus)
  • Scientific Name: Atrosalarias fuscus
  • Size: 4-5 inches
  • Origin: Indo-Pacific
  • Tank Size: 30 gallons

The black sailfin blenny moves in the crevices of an aquarium nearly undetected. These fish are very dark brown and sometimes black. They may have some dark red or yellow highlights.

These fish are most aquarist’s favorite specimens as they can easily tackle a green hair algae problem. However, like most blennies that eat algae, appetite will vary from one individual to the next; while one black sailfin might clear a tank of hair algae, one might leave it untouched in another. That being said, these fish still require a mainly herbivorous diet, supplemented with spirulina and blanched vegetables.

The black sailfin is native to sheltered reefs and estuarine ecosystems throughout the Indo-Pacific Ocean.

14. Two Spot

  • Scientific Name: Ecsenius bimaculatus
  • Size: 1-2 inches
  • Origin: Western Pacific Ocean
  • Tank Size: 10 gallons

The tail spot blenny, also known as the twin spot blenny, is a perfect fish for a nano or pico aquarium. These fish only grow to be a couple of inches big and stick to one spot in the tank, meaning that hobbyists have had luck keeping them in aquariums as small as 5 gallons. Bigger tanks may allow multiple two spots as these fish are generally peaceful to one another. However, they will easily be outcompeted and intimidated by more active and aggressive species.

The two spot blenny is specific to parts of the Philippines and northeast Borneo. They are often found alone on shallow reefs and especially find shelter among marine sponges.

15. Linear

  • Scientific Name: Ecsenius lineatus
  • Size: 3-4 inches
  • Origin: Indo-West Pacific
  • Tank Size: 30 gallons

The linear blenny is identified by the white line that cuts through the segmented brown patches on its dorsal portion; the underside of the fish is nearly pure white, which is an unusual color to see on a bottom-dweller.

This species is peaceful and reef-safe like other fish in its own taxonomic group. Some care should be given when placing these fish with corals though as they have been known to nip at small polyp stony (SPS) corals and immature colonies of large polyp stony (LPS) corals.

The linear blenny can be found throughout much of the Indo-West Pacific in distinct pairs. They live in coral-rich shallow waters but may venture to greater depths in varying regions.

16.Molly Miller

  • Scientific Name: Sartella cristata
  • Size: 4 inches
  • Origin: Carbbean Ocean
  • Tank Size: 30 gallons

The Molly Miller Blenny (video source) also known as the Combtooth blenny, is a fish with a thick appearance than the others on this list. Their head has two hair like appendages and they have larger eyes. It’s also one of the few fish that are reported to eat Aiptasia as well as cyanobacteria. It’s one of the lesser known blennies that offer a lot of utility to their owners.

Blenny Vs Goby

It’s often common to mistaken both of these species if you are new to the hobby, but there are several signs to know that differentiate them. As described by Jeff Kurtz from TFH Magazine:

Gobies typically have two distinct dorsal fins while blennies (with exceptions, of course) have one long continuous dorsal fin. The aforementioned cirri can also be a distinguishing characteristic, as they are not present on gobies.

The pelvic fins of many gobies are fused together. In some species, the fins are fused to the extent that they form a suction disc, which helps secure the fish to its rocky purchase on the reef. However, one could argue that fused pelvic fins are not necessarily easy to spot while looking over a specimen that is resting on the bottom of a tank at your local aquarium store.

TFH Magazine

FAQs

What is the best blenny for a reef tank?

The best blenny will be the one that fits your tank best. In general, algae blennies, starry blennies, Midas blennies, and tail spot blennies seem to be the most commonly kept.

There are a few things to consider before choosing a blenny for your tank though, like if the species is known for eating coral and invertebrates, and if they rely on natural-growing algae for a big chunk of their diet.

What is the best blenny for eating algae?

Lawnmower blennies are some of the best algae-eating fish available. That being said, some individuals can be picky eaters and might not even touch the algae growing in your tank.

Another good alternative would be the starry blenny.

Can you have 2 blennies in a tank?

In general, it’s recommended to only keep one bottom-dwelling species of fish per aquarium, including blennies. Most species of blenny are aggressive towards similar-looking fish in terms of shape and color.

It is possible to keep a bonded pair of blennies together though, and some hobbyists do keep multiple females or males of the same species together if the tank is big enough.

What marine fish is similar to the blenny?

Goby fish are sometimes mistaken as blennies, like the scooter goby. These fish belong to the Gobiidae family and feature the same blunt heads and elongated bodies that blennies do.

What is the most peaceful blenny?

Most species of blenny found within the aquarium hobby are peaceful and reef-safe. In fact, some blennies are so peaceful that they get overwhelmed by more active fish, like the two spot blenny.

As long as you only keep one blenny species in the lower level of the water column, then these fish should get along with the majority of tank mates.

What type of fish are blennies?

Blennies are bottom-dwelling fish that belong to the Blenniiformes order. Nearly 900 different species of blenny have been described, though many aquarium blennies originate from the Meiacanthus and Ecsenius genera.

Only certain members of this family are considered to be true blennies:

  • Blenniidae
  • Chaenopsidae
  • Clinidae
  • Dactyloscopidae
  • Labrisomidae
  • Tripterygiidae

What do blenny fish do?

Many species of blenny are bottom dwelling fish that originate from shallow water ecosystems, often with rich coral life and diversity. These fish swim from one rock to the next, perching and waiting until they find algae to graze on or small invertebrates.

It is also not uncommon to find a blenny digging a crevice out from between a rock and the substrate as a home base.

What does a blenny fish eat?

Some blennies are only herbivores, while others have a meat-dependent omnivorous diet. What your blenny eats will depend entirely on the specific type of blenny. If keeping a mainly herbivorous species, then the aquarium should be mature with algae. Supplemental plant based foods may also need to be given.

Final Thoughts

Saltwater blennies are a staple of the marine hobby. These saltwater fish bring life and color to the bottom of the aquarium, get along with most tank mates, and can be safely kept with a variety of corals and invertebrates. That being said, some species of blenny have been known to pick at corals, but there are plenty of species that offer algae eating services as well.

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