El sleepy fish is identified as a small blenny of elongated and slightly compressed body. The head has a very inclined profile from the eyes, located in the upper part, to the mouth, in the lower part.
Above the eyes it has a pair of simple tentacles, longer than the diameter of the eyes and the less branched nasal tentacles. The mouth has two canine teeth and a single row of small teeth in each jaw. The dorsal fin shows the front half noticeably higher than the rest, between both areas there is an evident one in males in heat.
El base color is typically beige or greenish-yellowish if the fish is on a bottom covered with algae, with six darker transverse bands, which can be divided and extended to the dorsal fin. These bands are surrounded by lines of a blue color, darker in males than in females.
If the fish is in the middle of the mussels, the body has a silver-gray color and the transverse bands are almost black. On the sides of the head, behind the eyes, it has a blue spot edged with red, especially visible in males.
Their habitat is frequently less than a meter deep, which generally it is found on rocky blocks, with tussock vegetation and moderately shakes. The sleeper is very active, feeding on small invertebrates and algae.
El sleeper fish breeds in early summer, and during this time the males show a true tenacity, follow and make the court, ostentatiously raising the dorsal fin, moving the head from one side to the other and even hitting any female that passes by in order to convince her to to accompany you to the nest.
During the breeding season the males become very territorial and fights between them are frequent.