Since they are a very active fish, Blennies make a good addition to a lively aquarium!
Blennies are long, blunt headed fish. The male blennies are usually larger and more colorful than the females. The male may also change colors before and after spawning periods.
Blennies like to perch in the rocks and will enjoy an aquarium with plenty of rockwork or live rock. They like to swim from 'hiding place' to hiding place in search of their natural food which consists of both algae and small fishes. Some blennies have been known to be somewhat territorial, so care should be taken if you put them in with fish less than twice their size.
For more Information on keeping marine fish see:Guide to a Happy, Healthy Marine Aquarium