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Related FAQs: Blennioids, True/Combtooth Blennies, Algae-eating Blennies, Saber-Tooth Blennies, Tube Blennies/Chaenopsidae,

Related Articles: True/Combtooth Blennies, Algae Eating Blennies, Saber-Tooth Blennies, Labrisomids, Convict "Blennies", FW to Brackish BlennioidsTube Blennies/Chaenopsidae,

Pico, Nano, Mini-Reefs; Small Marine Aquariums: Design, Set-Up, Stocking & Maintenance

Subtitle: Successfully Keeping Under 40 Gallon Saltwater Systems

Blennies, Blennioids
for Small Marine Aquariums


By Bob Fenner


            Likely the first group of fishes that comes to mind when thinking small system stocking are gobies and blennies These mostly small fishes are delightful in their behavior, generally hardy, mostly easygoing in terms of compatibility and there are many species available on a punctuated basis.

            The few downsides to keeping these fishes is their sedentary life style spending most of the time resting on the bottom, often out of sight. Some species are compatible with most all other fishes, invertebrates, but others are very territorial; and sexes, numbers can be important. Here Ill cover the blenny and blenny-like fishes that are most often encountered. Don't let this scant coverage steer you from trying other species you may well encounter; as new, even scientifically undescribed ones pop up all the time in the trade.  

            As with too many groups of organisms, there are a few blenny like (related blennioid, and just blenny-appearing) groups of fishes lumped as blennies. For our purposes, practical husbandry, we can and will ignore particulars of popular categorization and again, list those that occur to hobbyists as such.


The Best Blenny Choices:


Blennies and their relatives are a large and disparate group of principally small, sedentary fishes with long continuous dorsal and anal fins and stumpy pelvic fins (rather than the suction-cup like one's of gobies).

            The name "blenny" is about as ambiguous as "bass" or "eel". All told there are six families of 127 genera and 732 species of "true" Blennioids (a suborder of the largest order of fishes, Perciformes). They are united for a variety of technical internal structural similarities that we won't get into (See Nelson).

What you can sort of see from their outsides is that Blennioids have pelvic fins with usually one embedded spine and 2-4 simple soft rays; and that these fins are inserted in front of the pectoral fin bases. 

Look at a "typical" blenny; they have longer than deep pectorals, generally a long and continuous dorsal fin (unlike the separated ones of the gobies whom they share the bottom with), and various "hair", "whisker", "eyebrow" processes called cirri that add to their comical appearance. Yes, these fishes are characters.


Triplefin Blennies, Family Tripterygiidae:

            You have to look real close, but these fishes are distinguished by having three-partitioned dorsal. The 20 some genera, 200 some species of Triplefins can be further distinguished from similar gobies by the position of scales, more pointed snouts and how they perch... on their narrow ventral fins rather than a "goby disc". Some species live principally in borrowed holes/tunnels in rock, formed by other organisms. Some notable species:

Enneapterygius mirabilis Fricke 1994, Miracle Triplefin. 2.7 cm. SW Pacific. S. Sulawesi pix.

Helcogramma maldivensis Fricke & Randall 1992, the Maldive Triplefin. Western Indian Ocean: endemic to the Maldives.


Helcogramma striata Hansen 1986, the Tropical Striped Triplefin. Western Pacific; Southern Japan, Philippines to Australia, Solomon Islands. To about an inch and three quarters length. Found commonly on corals and sponges. This one off of Palau Redang, Malaysia.


Tube, Pike, or Flag Blennies, Family Chaenopsidae ("Key-Nop-Sah-Dee"):

            These blennies have elongated scale less bodies that are compressed somewhat side to side, and have no lateral lines; are otherwise modified for living in tube-like tunnels. There are nine genera with at least eighty species, Atlantic and Pacific. Acanthemblemaria, Chaenopsis, Coralliocetus, Hemiemblemaria, Emblemaria & Protemblemaria species are sold, mainly to reef keepers.

Acanthemblemaria spinosa Metzelaar 1919, the Spinyhead Blenny. Tropical West Atlantic. To 2.8 long. Here in a hole in Key Largo.

Lucayablennius zingaro (Bohlke 1957), the Arrow Blenny. 3.8 cm. Western Central Atlantic: Bahamas and Caribbean, including the Antilles. Here at Grand Turk.


True, or Comb-Tooth Blennies, Family Blenniidae:

            This is the principal family of blennies, having typical scale-less bodies with large blunt heads that bear their namesake comb-like teeth. There are some six tribes, fifty three genera with about three hundred fifty species of true blennies. Atrosalarias,  Ecsenius, Meiacanthus, Petroscirtes, Ophioblennius, Cirripectes, Parablennius, Istiblennius, Salarias are the genera whose members are most often offered to the hobby. Mainly Ecsenius spp. are available, useful; the common algae eating blennies of the genera Atrosalarias and Salarias get too big and rambunctious for small systems. Likewise, unless they're the only fish in the system, members of the genera Cirripectes and Ophioblennius are too territorial to safely place as anything other than solo presentations.

The Genus Ecsenius:

            The genus Ecsenius deserves special attention in the family Blenniidae; with forty seven species these are delightful, small (to four inches) fishes that do superbly well in peaceful fish, invertebrate and reef systems. Ultramarine ran an article by me on this genus (Dec. 08, Jan. 09). A collage of my pix of members of the genus is below.

Petroscirtes: 23 valid species, 31 nominal.

Petroscirtes mitratus Ruppell 1830, the Floral Blenny. Indo-Pacific; Red Sea, eastern Africa to Micronesia. To two and three quarters inch total length. This one in a typical setting hanging off a mooring line with algae about it. 


Saber-Tooth Blennies, Family Blenniidae, Tribe Nemophini: 

These fishes are marine (excepting Meiacanthus anema which ventures into brackish and freshwater), found in the Indian and Pacific Oceans. They are notable for having all their fin rays unbranched and are long in appearance, some almost eel-like. Five genera (Aspidontus, Meiacanthus, Petroscirtes, Plagiotremus, Xiphasia) with about fifty species. 

The Sabertooth Blenniids of the genera Aspidontus and Plagiotremus should be avoided at all costs (unless you want to keep one to a tank by itself or with non-fishes). These vampires have a pair of enlarged canine teeth in their lower jaw for ripping scales and bits of flesh from other fishes. Some do this by stealth, hiding in a hole in the reef and darting out for a fast-attack chomp. Others are sophisticated underwater con-artists, closely mimicking benign, even beneficent fishes.

An opposite benefit is conferred by the Forktail Blenny Meiacanthus oualanensis on the Canary Blenny (one of many with the same common name), otherwise better called the golden mimic blenny Plagiotremus laudandus flavus. As you know, very few fishes tangle with the blennies of the genus Meiacanthus due to their venom-gland bearing enlarged canines. The canary/golden mimic blenny, bold phony that it is, swaggers about in upper waters without fear.

The genus Meiacanthus: these beautiful, delicate-appearing blennies possess strong predator deterrents; enlarged canine teeth with associated venom glands. Unlike most Blennioids Meiacanthus have a fully functional swim bladder and "strut their stuff" above the bottom with impunity.

Despite their fangs, the genus makes good general aquarium and reef tank additions, being left and leaving other fishes alone. Though the genus' venomous bite does not rival a stone or lionfish sting it is painful to humans. I would avoid hand-feeding them.

The Yellow, Forktail, Vampire or Canary Blenny Meiacanthus ovaluanensis should definitely be mentioned. It is a standard blenny offering. Two of my other favorites in the genus are the longitudinally striped M. grammistes and M. atrodorsalis, though there are plenty more. There are twenty two described species in this genus.

Meiacanthus atrodorsalis (Gunther 1877), the Yellowtail Fangblenny. Western Pacific; W. Australia to Micronesia, Samoa. To 11 cm. Off Queensland, Australia and N. Sulawesi, Indonesia. 

Meiacanthus bundoon Smith-Vaniz 1976, the Bundoon Blenny. Pacific Ocean: Fiji and Tonga. To 8 cm. This one at House of Fins in CT.

Meiacanthus grammistes (Valenciennes 1836), the Striped Poison Fang Blenny. West Pacific; Indo-China to Micronesia. To a little over in four inches maximum length. One in Bunaken/Indonesia, the other in captivity.

Meiacanthus nigrolineatus Smith-Vaniz 1969, the Blackline Fangblenny. Western Indian Ocean; Red Sea and the Gulf of Aden. To 9.5 cm. This one off of Na'ama Bay, Sharm.



Meiacanthus ovalauensis (Gunther 1877), the Yellow Forktail or Canary Blenny. Western Pacific, Fiji Islands. To about four inches in length. A beautiful import from the South Seas. Feeds on plankton.

Petroscirtes: Ten described species.

Petroscirtes breviceps (Valenciennes 1836), the Shorthead Sabretooth Blenny or Striped Poison-Fang Blenny Mimic. A mimic of Meiacanthus grammistes (see above) (most easily told apart by Petroscirtes underslung mouth). Indo-West Pacific; East Africa to the Micronesians. To 11 cm. Can and will bite if handled. N. Sulawesi pic. 


Petroscirtes mitratus Ruppell 1830, the Floral or High Fin Blenny. Indo-Pacific; Red Sea to Samoa. To a little fewer than three inches in length. This two inch one photographed in the Maldives. 

Family Labrisomidae:

Labrisomid Blennies; some of these are livebearing (Xenomedea & east pacific species of Starksia). Several Labrisomids live in close conjunction with sea anemones and have protection from their stings. Sixteen genera with about a hundred species; Atlantic and Pacific, mostly tropical. Genera I've seen offered in the trade are Labrisomids, Starksia, Neoclinus, Exerpes, Paraclinus, Dialommus, the worm-like Stathmonotus, and Xenomedea.

Malacoctenus bohlkei Springer 1959, the Diamond Blenny. Tropical West Atlantic; Bahamas to Belize. One off of South Bimini by RMF, another in Grand Turks by Di. To about two and a half inches in length. Easily approached underwater, once observed!

Malacoctenus triangulatus Springer 1959, the Saddled Blenny. Western Atlantic; Bahamas to Brazil, St. Paul's Rocks. To three inches in length. One happily perched on a leather yellow coral in captivity, another in the Turks.



Picking out the right species that are clean, not-too-badly beaten by catching and transport is absolutely critical with these fishes. Blennies are tough, tough, tough, given that they are tropical species (for warm water systems), haven't been "thermally challenged", or thwacked by careless handling:

Caution: Re Cold Water Species: Many of the blennies sold in the trade are temperate, even cold-water organisms that won't sustain the rapid move to tropical aquariums. Don't be fooled; cool/cold water marines will generally live for a few days to weeks before dying "anomalously". You need to consult two or more reference works to determine which species you're looking at and its needs.

By all means DO keep the cool/cold water blennies if you have a chilled tank/cool water reef system; they are great for such systems. I prefer some of the Blennius and Parablennius.

Collecting & Shipping Damage: Is difficult to assess with such small and secretive fishes, but necessary. Blennies are scaleless or have small embedded scales; they are otherwise protected from physical injury by their copiously slimy bodies (another common name for the blennies is slimefishes). If they are roughly handled or scrubbed clean of mucus by physical insult or water quality causes they can perish quickly. Look closely at their undersides and fin origins for evidence of reddening. Closely observe all the specimens offered; when one breaks down, very often the rest will as well.

Alertness: Being target food organisms, the Blennioids are aware of all in their environment. Specimens offered for sale should be looking around, and conscious of your presence. Don't buy dazed blennies.

Feeding: The last thing blennies do before dying is not breathing, it's eating. For their size, these groups are huge gluttons. Should a prospective buy refuse food, something is very wrong.


Many blennies are prodigious diggers that appreciate a bottom with mixed size rubble and gravel. You should know that such blenny species will not ever be satisfied with having dug under any and everything. They literally dig until they die; arrange your decor accordingly. Rock, coral et al. that can be toppled, will be.

About jumping: With their big heads and elongate bodies you might think these fishes incapable of launching themselves out of your tank. Think again, they are notorious jumpers. Keep your tank covered.

Territorial Behavior:

There are blenny species that are easy going with their own kind and others, and some that are very quarrelsome. When, where in doubt keep them one species and specimen to a small tank.

Predator/Prey Relations:

Yes! Blennies are for the most part food items for predatory fishes and invertebrates. They need more than just to be kept apart from large mouths to feel safe; provide plenty of cover, nooks and crannies.


This may sound a little strange, but blennies should be "Boris Karloff'ed". Like a mad scientist, you ought to pour off their shipping water, and "mixed" system water a few times to dilute the slime and other chemicals they produce in transit. Finally, lift the specimen and place it in the system and toss the mixed (and now diluted) shipping and system water. Blennies produce and release chemicals that affect their and other fish behavior and this procedure will help you dilute their effect.

Turn the system lights down or off for the first few days on placing new shy fishes like the blennies.


Almost all blennies produce large demersal (bottom) eggs that they place in a sheltered hole. And talk about women's liberation, the male alone tends and defends the eggs after spawning.

Males tend to be larger than females; sometimes they are also differently colored, mostly during spawning.


Most of the blennies are carnivores that can be coaxed to join their omnivorous brethren in consuming small invertebrates (brine shrimp, Mysids, worms...) and algae, flakes, even pellets in captivity. Note that their food must be small enough to just swallow; blennies do not chew.



Are you looking for small, intelligent to the point of being charming "bottom" fishes? Look no further, but do investigate the species you have in mind or tank. Blennies and smaller blenny-like fishes are indeed interesting, hardy and long-lived, as long as you have yours in the right temperature regime.


Bibliography/Further Reading:

Baensch, Hans A. & Helmut Debelius. 1994. Marine Atlas, v. 1. MERGUS, Germany.

Brown, Gregory W. The Combtooth blennies, from the kelp forests to the world's coral reefs. Discover Diving 3,4/92.

Burgess, Warren E., Herbert R. Axelrod & Ray E. Hunziker. 1990.

Atlas of Aquarium Fishes, v. 1. Marines. T.F.H. Publ. NJ.

Dakin, Nick. 1992. The Book of the Marine Aquarium. Tetra Press.

Fenner, Robert, 08-09. Blennies of the genus Ecsenius. Ultramarine Magazine 12/08-1/09.

Howe, Jeffrey C. 1995. Original descriptions; Cirripectes alleni, Ecsenius randalli. FAMA 10 & 11/95.

Hunt, Philip. 1993. The midas touch. TFH 2/93.

Hunt, Philip. 1995. The vampire canary (Meiacanthus). TFH 5/95.

Kahl, Burkhard. 1972. Blennies of the Mediterranean. Aquarium Digest International 1:2(72).

Nelson, Joseph S. 1994. Fishes of the World, 3d ed. John Wiley & Sons, NY.

Parker, Nancy J. 1976. Piscatorial clowns. Marine Aquarist 7(4):76.

Pyle, Richard L. & A. Privitera. 1990. The midas blenny Ecsenius midas Starck.

Robertson, Graham C. 1975. North Sea blennies. Marine Aquarist 6(1):75.

Thresher, R.E. 1984. Reproduction in Reef Fishes. T.F.H. Publ., NJ.

Triplefins Bibliography

Burgess, Warren E. 1996. New Triplefins from Taiwan. TFH 4/96.

Howe, Jeffrey C. 1994. Original Descriptions: Enneanectes reticulatus. FAMA 4/94.

Pholidichthys Bibliography

Chlupaty, Peter. Undated. P. leucotaenia- the white-striped eel goby. Aquarium Digest International #34.

Wirtz, Peter. 1991. Goby or blenny. TFH 10/91.

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