Blennies (blennioidei) are, for the most part, aquacultured, small eel-like fish with interesting large eyes and mouth. Their heads are blunted and some possess decorative whiskers. They normally mull around the sea floors, burrowing in the sand, but will also creep around crevices in reefs where it will pick at live crustaceans. All aquariums should house a blenny to help maintain a healthy system.