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Related FAQs: Algae-Eating Blennies 1, Algae-Eating Blennies 2, & Marine Algae Eaters, Marine Algae Eaters 2, & Algae Eating Blenny (AEB) Identification, AEB Behavior, AEB Compatibility, AEB Selection, AEB Systems, AEB Feeding, AEB Disease, AEB Reproduction, & Ecsenius Blennies, True Blennies, Saber-Tooth Blennies, Blenny Identification, Blenny Behavior, Blenny Compatibility, Blenny Selection, Blenny Systems, Blenny Feeding, Blenny Disease, Blenny Reproduction, Blennioids & their Relatives,

Related Articles: Scavengers/Clean-up Crews for Marine Aquariums, by Bob Fenner, Some Fishes Are Good For More Than Just Looking At, by James Fatherree, Combtooth Blennies, Blennioids and their Relatives, Sabretooth Blennies, Family Blenniidae/Tribe Nemophini, Algae Control, Triplefin Blennioids,

/The Conscientious Marine Aquarist

Algae-Eating Blennies of the Genera Salarias and Atrosalarias

by Bob Fenner

Ah, yes

There are several (from the Middle English word meaning "many") species of blennies that principally consume algae... A cursory view of the ones that have been listed as members of the genus Salarias on fishbase.org will show a grand number of 159... but for our purposes here, we'll discuss the two genera, three species of comb-tooth blennies (family Blenniidae) that are specifically sold as "Lawnmower or algae blennies" largely in the trade.

    Mostly employed as erstwhile nuisance algal cleaner-uppers, the genera Atrosalarias and Salarias blennies are well-deserving of their prodigious green-eating capacity, and can make good tankmate fish additions, given a few caveats. One, that they are placed in well-established settings (with sufficient edible algal growth), of adequate volume (most die from starvation... indirectly from being placed in too small quarters... Thirdly, that they not be housed with overly-aggressive nor habitat-sharing organisms (they're feisty to put it mildly, and don't like sharing the bottom algal patch they call home).

Species on Parade:

Genus Atrosalarias: Monotypic (one species).

Atrosalarias fuscus (Ruppell 1838), the Brown, (Black, yellow as juveniles...) Sail/Highfin Blenny... Coral Blenny (though it can be yellow, very dark...). A popular reef aquarium fish for its prodigious filamentous algae feeding. Western Indian Ocean; Red Sea to Pakistan. To about four inches in length. Two aquarium images or juveniles and one adult in Raja Ampat, Indo. http://fishbase.org/Summary/speciesSummary.php?ID=17462&genusname=Atrosalarias&speciesname=fuscus+fuscus
Verticals (Full/Cover Page Sizes Available
Bigger PIX: The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.

Salarias, Lawnmower Blennies. Much-loved by aquarists as algae groomers. Seven nominal species, two of which show up in the trade/hobby regularly.

Salarias ceramensis Bleeker 1852, the Seram Blenny. Western Central Pacific, Indonesia, Philippines and PNG and northern Australia. To six inches in length. This one in an aquarium.

Salarias fasciatus (Bloch 1786), the Jeweled Blenny to science, super-popular Lawnmower Blenny to aquarists. Indo-Pacific; Africa and Red Sea to Micronesia. To five inches in length. Aquarium and Australian waters images.

Verticals (Full/Cover Page Sizes Available
Bigger PIX: The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.


    As with most territorial fish species, these blennies are best purchased small, and placed near last to provide your best chance at establishing a livable pecking order. How small is small? Two inches for Atrosalarias, two and a half to three maximum for Salarias spp.

    Take care to not purchase a "too-thin" specimen that has been on hand and starved for too long, but on the other hand, don't be too anxious to acquire a just arrived individual either. Ones that are going to "die mysteriously" do so most often in the first few days of arrival.

    Torn fins are not indicative of a doomed specimen, as these blenniids are rapid healers. Cloudy eyes, missing scales, sores on the body would disqualify a purchase however. Do watch/observe carefully for active, inquisitive behavior, hallmarks of a winning specimen.

Captive Habitat:

    Expanding on the above environmental conditions, the size, maturity of a given system intended for these fishes is paramount in determining your successfully keeping them. Even starting with the smaller Atrosalarias fuscus or a very small specimen, a minimum of an undercrowded sixty gallons with this or more pounds of matured live rock is suggested. As you will find, these species claim an easy equivalent of bottom space as their own as this... With a hundred gallons per for a full size (five inch or so) Salarias fasciatus, being about right.


    These are by nature territorial fishes, that will drive out other animals, including of their own kind, from their algal patch area... how to put this.... with extreme prejudice. Algae eating tangs like Ctenochaetus, many Zebrasoma, small Rabbitfishes/Spinefoots... sessile invertebrates that make their living rasping the bottom, may have a tough go at living in the same small space as these blennies. If you would like to try mixing them, do place the blenny last.

    Other blennies/oids and families of fishes are generally ignored, or just chased for the halibut by algae blennies, as long as their not filamentous algae eaters.


    These fishes are algae eaters par excellence, but not all algae. The vast majority of their diet in the wild is made up of filamentous green algae species... a bit of red (Rhodohphyte) and brown (Phaeophyte)... they don't eat all types (e.g. not "bubble", Family Valoniaceae), species, and almost entirely ignore Cyanophytes, aka Blue Green Algae... that despite its common name occurs in all colors, and shapes... blue, black, green, red... almost always slimy to the touch. Most types of prepared, meaty foods are ignored, or if taken, with not enough enthusiasm to support these fishes.

    Often, with aging of a captive system, there will be a shift in the make-up of micro- and macro-life that predominates... and a valuable lesson for observant aquarists in the loss of fodder for such grazers as these blennies. The very best gauge of such incurring change is a thinning of said fishes... first in the gut area, but spreading to the upper flank musculature. Such changes can occur quickly, in days, and supplemented foods must be made available to prevent loss. Of most use are prepared foods in the form of sinking wafers and pellets that are largely algae-based. Various of these have been shown to be accepted with gusto.

    Alternatively, cultured macro-algae, dried people-intended algae like Nori, Kombu... can be tried, and with familiarity are generally accepted as well. For true "die-hards" hoping to entrain natural behavior, "algae rocks" can be cultured elsewhere (as in a lighted sump) and rotated into the main system periodically.

Diseases/Prevention & Cure:

    Algae blennies are the epitome of industriousness... only taking time to rest during daylight hours between surveying their domain and nipping at loose bits of filamentous algae. One that is too sedentary is trouble, and a wake-up call to check your water quality and/or gear.

    These blenniids are subject to the usual reef fish scourges, and amenable to the usual treatments, though they shy on the narrow margin in actual treatment regimens and chemical concentrations. Hence you should take care to know the actual gallonage of the water being treated, and use test kits... often and regularly if/when dosing them.

    Most transferable ailments can be excluded by a two week quarantine period prior to placing them in your main system, with a suggested Methylene Blue and pH-adjusted freshwater dip enroute.


    Thus my pertinent notes re the aquarium use of these two genera's members... Comical, tough and only-to-a-degree (compared with the Blennies of the genus Ophioblennius: ten described species,  which can be territorial terrors.

Ophioblennius atlanticus (Valenciennes 1836), the Atlantic The Red-Lipped Blenny. Tropical Eastern and Western Atlantic. To more than seven inches in the wild. Aquarium images.

Ophioblennius steindachneri Jordan & Evermann 1898, the Largebanded Blenny. Tropical Eastern Pacific. To a bit over seven inches in length. At right off of Cabo San Lucas, Mexico's Baja. Below, a juvenile and adults in the Galapagos.

Atrosalarias and Salarias blennies can be put to good use in established marine systems of good size, with filamentous green algae in abundance (or supplementary feeding) and a dearth of tankmates with similar feeding strategy.

Bibliography/Further Reading:

Your book is available in the Kindle Store! – 09/10/13
Oh yes; a new e-book on marine algae and their control in aquariums; can be borrowed for free w/ Kindle, for Prime members. Enjoy. B
Congratulations, your book "Marine Aquarium Algae Control" is live in the Kindle Store and has been enrolled in KDP Select. It is available* for readers to purchase here.


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

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.

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

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

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