All fish / Blenniidae

Bicolor Blenny

Ecsenius bicolor

Also known as bicolour blenny, two-colour blenny, bicolor combtooth blenny, flame tail blenny, bicolor blenny, フタイロカエルウオ, 双色鳚, 双色异齿鳚

A slim combtooth blenny whose front half is usually dark brown to blue-black while the rear half turns bright orange or yellow, though it can switch colours with mood and breeding state. It perches on rocks and peeks out of holes, giving it a lot of character, and it helps graze nuisance algae in reef tanks.

Care at a glance

Care level

Easy

Temperament

Semi

Adult size

10 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

110 litres

Keep as

Keep singly, or as a mated pair in a large tank

Diet

Omnivore: grazes algae and film; offer marine flakes, nori, mysis and frozen brine shrimp

Swims

Bottom of the tank

Lifespan

3 to 5 years

Water

Marine (saltwater)

Wild range

Indo-West Pacific: Maldives and Indian Ocean to Micronesia, Great Barrier Reef and Phoenix Islands

Breeding

Males guard eggs laid by the female inside a hole or shell, and the larvae are planktonic. Spawning happens fairly often in captivity, but rearing the tiny larvae is difficult.

Good to know

Generally reef safe, though it may nip at clam mantles or coral polyps if underfed. It can be territorial towards other blennies and similar-shaped fish, so avoid keeping several in small tanks.