Lawnmower Blenny (Salarias Fasciatus)

Also Known As: Jeweled Rockskipper, Algae Blenny

Compatibility and Behavior
The Lawnmower Blenny (Salarias fasciatus) is one of the hobby's favorite algae-control workhorses, and the "lawnmower" nickname is well earned, since this is a fish that spends its day scraping film and filamentous algae off rock and glass with comb-like teeth built for exactly that job. It's a good-looking grazer, too: a mottled body in brown, olive, tan, and cream broken by darker vertical bands and scattered with tiny glittering blue-white spots that give it a jeweled look, topped by a wide, blunt head and high-set, speckled-ringed eyes. Males show elongated rays along the front of the anal fin. It's fully reef safe, no threat to corals or inverts, and it may pick a little algae right off coral bases without harming the tissue. Temperament is peaceful toward most tankmates, but it can get territorial with other blennies or similarly shaped fish it sees as competition, so it's best kept as the only blenny in the tank unless the system is fairly large. Otherwise it pairs happily with clownfish, gobies, wrasses, dottybacks, and other easygoing reef fish.

Aquarium Requirements
The single most important requirement here is often overlooked: this fish eats algae, so it needs a tank that actually grows some. A well-established system of at least 30 to 40 gallons that's had several months to develop a healthy film of algae and biofilm across the rock and glass is what keeps a Lawnmower fed, where a brand-new setup with bare rock can leave one slowly starving. Give it plenty of rockwork with caves, ledges, and overhangs for grazing surface and secure perches to rest on between feeding runs. A tight-fitting lid is a sensible precaution, since it can jump when startled, especially during acclimation. And if the natural algae runs thin, supplement with nori, spirulina, or algae wafers a few times a week so it doesn't thin out or go off its food.

Specifications
Approximate Size: Sm/Md: 1.5–2.25", Lg: 2.5–3"
Diet: Herbivore; filamentous algae, diatoms, biofilm, and detritus, supplemented with nori, spirulina, and algae wafers
Origin: Indo-Pacific
Care Level: Easy to moderate
Reef Safe: Yes
Temperament: Peaceful
Minimum Tank Size: 30 gallons
Special Considerations: Depends on natural algae and biofilm to graze, so it needs a well-established tank rather than a barren new setup, and should be supplemented with nori or algae wafers if growth runs thin; can jump, so a tight-fitting lid is recommended