Striped Kelpfish, Gibbonsia metzi

Striped Kelpfish, Gibbonsia metzi. Fish caught from within a tidal pool in coastal waters of Santa Cruz, California, March 2021. Length: 13 cm (5.1 inches). Catch, photograph, and identification courtesy of Chris Moore, Peoria, Arizona.

Striped Kelpfish, Gibbonsia metzi. Fish caught from within San Francisco Bay, San Francisco, California, March 2020. Length: 16 cm (6.3 inches). Catch, photograph, and identification courtesy of Chris Moore, Peoria, Arizona.

Striped Kelpfish, Gibbonsia metzi. Fish caught from within a tidal pool in coastal waters of Santa Cruz, California, March 2021. Length: 16 cm (6.3 inches). Catch, photograph, and identification courtesy of Chris Moore, Peoria, Arizona.

Striped Kelpfish, Gibbonsia metzi. Fish caught from coastal waters off Half Moon Bay, California, September 2023. Length: 16 cm (6.3 inches). Catch, photograph and identification courtesy of Ben Cantrell, Peoria, Illinois.

Striped Kelpfish, Gibbonsia metzi. Fish caught from the surf at Pescadero, California, August 2019. Length: 18 cm (7.5 inches). Catch, photograph, and identification courtesy of Kenneth Tse, Toronto, Canada. Identification reconfirmed by H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, California.

The Striped Kelpfish, Gibbonsia metzi, is a member of the Kelp Blenny or Clinidae Family, that is known in Mexico as sargacero rayado. Globally, there are four species in the genus Gibbonsia, of which three are found in Mexican waters all three in the Pacific Ocean.

The Striped Kelpfish has an elongated and compressed body and a small tufted cirrus around each eye. They are brown, green and red in color and can be weakly striped or mottled in darker colors. The pectoral fins are banded. The juveniles have the ability to quickly change colors to match their backgrounds. The adult color changes are slower and more subtle. Their head is elongated and pointed with a short bluntly pointed snout, a small terminal mouth, and modest-sized eyes. Their anal fin has 2 spines and 24 to 27 rays; their caudal fin is rounded; their dorsal fin has a very long base and is elevated at both end with 34 to 37 spines and 7 to 10 rays; their pectoral fins is rounded with 11 to 13 rays; and, their pelvic fins have 1 spine and 3 rays. A key to identification is that their dorsal rays are uniformly spaced. They have 3 or 4 gill rakers on the upper arch and 7 or 8 gill rakers on the lower arch. They are covered with scales.

The Striped Kelpfish are found demersally in the intertidal zone within algae beds including tidal pools, and within seaweed and the kelp canopy mid-water at depths up to 9 m (30 feet). They reach a maximum of 24 cm (9.4 inches) in length with females being larger than males. They feed on algae, small crustaceans, mollusks, and polychaete worms. 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 with females depositing eggs in nests attached to short seaweed at the bottom; eggs are vigorously guarded by males until they hatch in 12 to 17 days. Larvae and juveniles are transparent and form schools. When they reach 6.0 cm (2.5 inches) they become solitary and move to deeper waters. They have life spans of up to eight years. The Striped 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 Striped Kelpfish is a resident of the Pacific and found from just south of Guerrero Negro (Punta Rompiente, Baja California Sur, northward along the central and northwest coasts of Baja.

The Striped Kelpfish is very similar to, but larger than, the Spotted Kelpfish, Gibbonsia elegans (found in deeper waters; maximum length 15.7 cm; 5 to 8 dorsal fin rays; 12 – 16 gill rakers; dorsal fin rays 1 to 4 set close together).

From a conservation perspective the Striped Kelpfish is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature, seldom seen by humans, and difficult to catch by hook and line.