Bicolor Blenny – Ecsenius bicolor

The Bicolor Blenny (Ecsenius bicolor) has highly variable coloration, and may not have the typical appearance at the time of purchase. The front half of the Bicolor Blenny is usually dark purple-grey, and the rear is orange-yellow. During spawning, the male turns reddish with white bars and the female turns light brown and yellow-orange. After spawning the male becomes dark blue with light patches on each side of the body. The Bicolor Blenny is shy around larger fish and needs plenty of hiding places, but is otherwise peaceful towards other fish. Some individuals may become territorial.

Many different species and varieties of blennies enter the aquarium trade regularly. Some of the more commonly encountered genuses are Atrosalarias (the Sailfin Blennies), Blenniella (Rockskipper or Combtooth Blennies), Ecsenius (often small and flat-faced), Meiacanthus (the notorious fangtooth blennies), and Salarias (the popular algae-eating Lawnmower Blennies). Many blennies may eat some algae growing in the aquarium like the nuisance hair algae, or ornamental macroalgae like Caulerpa. Blennies will also accept many other types of food like pellets, frozen formulas, brine shrimp and others.

Blennies can be kept with most other community tankmates like damsels, clownfish and angels but they may become territorial with time and will defend against trespassers. Blennies typically do not tolerate others of the same species except in very large aquariums with enough territory to accommodate their need for space. They are safe for reef aquariums and will not harm most invertebrates, with the possible exception of small crustaceans like Sexy Shrimp. They spend most of the time on or around the bottom, or perching in the rockwork of the aquarium.