The barnacle blenny, Acanthemblemaria spinosa, also known as the tube blenny or spinyhead blenny, is a member of theblenny family native to the Pacific ocean. It has a mottled black, white and red coloration over the entire body, which is rather elongated. As with most blennies, the head of this animal has small hair-like appendages over the eyes, which are large and red. It ranges in size from 0.75 inches (19 mm) to 1.5 inches (38 mm) in length.
A. spinosa prefers to inhabit the empty shells of barnacles, hence their name, but will also live in rock and coral crevices. They are opportunistic feeders, preferring to quickly dart out and retrieve food bits from the water column, as opposed to engaging in active foraging and hunting behavior. They eat small crustaceans and other plankton.
(From Wikipedia, May 31st, 2012)