All fish / Blenniidae

Lawnmower Blenny

Salarias fasciatus

Also known as jewelled blenny, jeweled rockskipper, algae blenny, sailfin blenny, rock blenny, banded blenny, lawn mower blenny, lawnmower blennie, ヤエヤマギンポ, ikan blenny, 花斑跳岩鳚, 花斑蛇鳚

This is a mottled brown, green and white blenny with a long dorsal fin, small branched head cirri and big, expressive eyes. It spends its day perched on rocks scraping off algae, so people keep it for its character and to help control nuisance hair algae.

Care at a glance

Care level

Easy

Temperament

Semi

Adult size

12 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

115 litres

Keep as

Keep singly unless the tank is very large

Diet

Herbivore: grazes film and hair algae, plus nori, spirulina-based foods and algae wafers

Swims

Bottom of the tank

Lifespan

4 to 8 years

Water

Marine (saltwater)

Wild range

Indo-West Pacific, from the Red Sea and East Africa to Samoa, north to Japan and south to Australia

Breeding

It lays eggs in caves or crevices, and the male guards them until they hatch. Spawning sometimes happens in aquariums, but the tiny planktonic larvae are hard to rear, so captive breeding is rare.

Good to know

It needs a mature tank with plenty of algae and may starve if it will not accept prepared foods. It is often aggressive towards other blennies and similar-looking fish, and some individuals nip at clam mantles or coral.