Crevice Kelpfish, Gibbonsia montereyensis

Crevice Kelpfish, Gibbonsia montereyensis. Fish caught from the coastal waters off San Francisco, California, December 2012. Length: 15 cm (5.9 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

The Crevice Kelpfish, Gibbonsia montereyensis, is a member of the Kelp Blenny or Clinidae Family, that is also known as the Spotted Kelpfish and in Mexico as sargacero de Monterey. Globally, there are four species in the genus Gibbonsia, of which three are found in Mexican waters, all three in the Pacific Ocean.

The Crevice Kelpfish has an elongated and compressed body and a small tufted cirrus around each eye. They vary in color with various shades of brown, green, or lavender with dark and silver bars. Some fish are spotted, others are striped. Their fins are weakly pigmented at the base. Their sides have 12 bars that extend into the dorsal fin. Their caudal fin base has a thin dark line. Most fish have a large dark ocellus spot high on the body behind the pectoral fins. Some have bars radiating from the eyes. Their head is elongated and pointed with a short bluntly pointed snout, a small terminal mouth, and small eyes. Their anal fin has 2 spines and 23 to 28 rays; their caudal fin is rounded; their dorsal fin has 34 to 36 spines and 5 to 8 rays; their pectoral fins have 11 to 13 rays; and, their pelvic fins have one spine and 3 rays. A key to identification is that their dorsal rays are widely spaced at the rear of the fin. They have 3 to 5 gill rakers on the upper arch and 7 to 9 gill rakers on the lower arch. They are covered with scales except on the caudal base, a key to the identification.

Crevice Kelpfish are found demersally in the intertidal zone in rocky areas with algae on exposed coasts to depths up to 49 m (162 feet). They reach a maximum of 18.4 cm (7.2 inches) in length. They feed on algae, small crustaceans, mollusks, and polychaete worms. They rely on their cryptic colorations blending into their surroundings for defense. They are considered to be an important component of the food chain preyed upon by a large variety of forage fish, sea birds and marine mammals. Reproduction is oviparous. They have life spans of 3 years. The Crevice Kelpfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

In Mexican waters, the Crevice Kelpfish is a resident of the Pacific and found from just south of Guerrero Negro, northward along the central and northwest coasts of Baja.

The Crevice Kelpfish is very similar to the Spotted Kelpfish, Gibbonsia elegans (scales on their caudal fin base).

From a conservation perspective the Crevice Kelpfish is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature, caught on occasion by pier fishermen but are difficult to catch by hook and line and seldom retained.