Lawnmower Blenny

The Lawnmower Blenny (Salarias fasciatus) is a constant grazer that spends the day rasping algae and biofilm from live rock, helping keep hard surfaces cleaner. Its mottled olive-to-brown body, pale spotting, and small head cirri give it a camouflaged “rock-percher” look common to combtooth blennies.

What You’ll Observe:

• Short hops between rock ledges, followed by long “perch and watch” pauses
• Repeated grazing passes over the same favorite rocks and tank glass edges
• A regular “home perch” it returns to after feeding rounds
• A rounded belly by late day when grazing conditions are strong
• Occasional face-to-face posturing if a similar-shaped fish works the same area

To do well, provide a mature reef with plenty of established live rock surface for natural grazing and multiple perches. Supplement by placing plain dried seaweed on a clip or rubber-banding it to a small rock, and mix in algae-forward frozen or pellet options so it learns multiple feeding stations. With steady grazing opportunities, it becomes a reliable, day-active presence in the lower rockwork.

Will it definitely eat long hair algae?
Many focus first on film algae and microalgae on rock and glass; some individuals also work on longer strands, but grazing preferences can vary fish to fish.

How can I get it to accept prepared foods more consistently?
Offer food in the same place each day (like nori on a clip or a small rock), and keep portions small so it can investigate without competition from faster swimmers.

Why does it “sit” on a rock for long periods?
Perching is normal blenny behavior—many spend long stretches watching from a ledge, then make quick grazing laps before returning to a favorite spot.

Can it be kept with other blennies?
In larger, rock-rich systems it’s often workable, but most hobbyists have the smoothest results when the tank has clearly separated perches and the other blenny isn’t a similar-looking algae grazer.

Is it normal for corals or clams to close when it grazes nearby?
Some will graze across any hard surface they land on; if a coral stays retracted, providing a dedicated grazing/feeding area (nori on a rock away from the coral) usually redirects attention.

We work with trusted suppliers who keep our specimens healthy and well-fed before shipping.