Tail-scaled Goby, Gobiosoma Species B

Tail-scaled Goby, Gobiosoma Species B. Fish caught from coastal waters off Puerto Peñasco, Sonora, May 2026. Length: 2.1 cm (0.8 inches). Catch, photograph and identification courtesy of Vince Golder, Santa Cruz, California.

The Tail-scaled Goby, Gobiosoma Species B, is a member of the Goby or Gobiidae Family, and known in Mexico as gobio cola escamosa. Globally, there are nineteen species in the genus Gobiosoma, eleven of which are found in Mexican waters, six in the Atlantic and five in the Pacific Ocean.

The Tail-scaled Goby has an elongated robust body with a large, rounded head that has an oblique mouth and very steep snout profile. Their eyes are set close together and the chin has two barbels. They have a tan background with their head heavily covered with dark blotches and a series of broken bars extending to the caudal fin. They have a small spot on the top rear corner of the gill cover.  The pectoral fins have spots at the top and the bottom. The anal, caudal pectoral fins are dusky. Their anal fin has 9 to 11 rays and their first dorsal fin has seven spines, their second dorsal fin has 1 spine and 11 to 13 rays; their pectoral fins have 18 to 21 rays; and, their pelvic fins are fused to the disc. The body is covered with large rough scales with the exception of the head which is scaleless.

The Tail-scaled Goby is a demersal species found in coastal lagoons and tidal at depths up to 10 m (33 feet). They reach a maximum of 2.1 cm (0.8 inches). Reproduction is oviparous. The Tail-scaled Goby is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, diet, growth, habitat, longevity, movement patterns, and reproduction.

The Tail-scaled Goby is a resident of Mexican waters of the Pacific but is limited to with west coast of the Baja Peninsula from Guerrero Negro, Baja California south to Magdalena Bay, Baja California Sur, in the northern third of the Sea of Cortez and along the coast of the mainland south to Mazatlán.

The Tail-scaled Goby can be confused with the Secret Goby, Chrolepis semisquamata (wide dark bar at the base of the caudal fin) and the Sonora Goby, Gobiosoma chiquita (lack barring on the side).

From a conservation perspective the Tail-scaled Goby has not been formally evaluated. They are very small in stature and of limited interest to most.