Bicolour Blenny

Overview

The Bicolour Blenny (Ecsenius bicolor), also known as the Two-coloured Blenny, is a pint-sized fish with an outsized personality. Its body is split between a blue-to-dull-brown front and a warm orange rear, and you'll usually spot it perched on the rockwork, peering out of a crevice with those big, expressive eyes before hopping to its next lookout.

Hardy, peaceful and reef-safe, it's a brilliant beginner fish that also happens to earn its keep — grazing film and hair algae off the rocks as it goes. Watching it dart between hidey-holes and claim a favourite perch never gets old.

It's widespread across the Indo-Pacific and undemanding to keep, asking for little more than a mature tank with plenty of rock and a varied, algae-based diet. For colour, character and a bit of natural algae control in one small package, it's hard to beat.

Compatibility

Toward the general community the Bicolour Blenny is peaceful and easygoing, mixing well with most calm reef fish — clownfish, cardinals, tangs and the like. It's a confident little character rather than a shrinking violet, but it doesn't go looking for trouble with unrelated species.

The caveat, as with most Ecsenius, is lookalikes and turf. It can get nippy toward other blennies, small gobies and dartfish, especially in tight quarters where they compete for perches and grazing space. As a rule, keep just one blenny of this type per tank unless the system is large, and give any similar-shaped tankmates their own territory. Avoid aggressive or much larger fish that might bully it.

Health & quarantine

The Bicolour Blenny is hardy and forgiving, one of the easier marine fish to keep, which is a big part of its appeal for newer reefers. A quiet quarantine period and a slow acclimation are still worthwhile to confirm it's feeding before it joins the display, and it settles fastest in a mature, established tank with natural algae growth to graze. Stable water quality and a varied diet are really all it asks for. As with all blennies, fit a secure lid — they're capable jumpers, particularly while settling in.