Flapscale Blenny, Paraclinus sini

Flapscale Blenny, Paraclinus sini, Male. Fish caught from coastal tidal pools on Los Conchas Beach, Puerto Peñasco, Sonora, April 2021. Length: 6.0 cm (2.4 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona.

Flapscale Blenny, Paraclinus sini, Male. Fish caught from coastal tidal pools on Los Conchas Beach, Puerto Peñasco, Sonora, April 2021. Length: 6.2 cm (2.5 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona.

The Flapscale Blenny, Paraclinus sini, is a member of the Labrisomid Blenny or Labrisomidae Family, and is known in Mexico as trambollito frondoso in Mexico. The scales have membranous flap-like projections on the posterior margins of the scales giving rise to their common name. Globally, there are twenty-three species in the genus Paraclinus, of which thirteen are found in Mexican waters, five in the Atlantic and eight in the Pacific Ocean.

The Flapscale Blenny has an elongated body with a uniform depth throughout that tapers gradually at the rear into the tail. They are heavily mottled in reddish brown or greenish brown with white blotches and flecks. They have white spots on the jaws, a white bar under the eye, and oblique white bar behind the eye, and some have diffuse dark bars on the sides. The have one or two small ocellated spots on the posterior half of the dorsal fin. Their head has a bluntly pointed snout with cirri present on the nostrils, above the eyes and on the nape. Their mouth is large and opens at the front. The anal fin has 2 spines and 16 to 20 rays; their dorsal fin had 28 to 30 spines with the first three being elevated with a deep notch before the fourth spine, no dorsal fin rays; their pectoral fins have 12 to 14 rays; and their pelvic fins have 1 spine and 3 rays.

The Flapscale Blenny is a shallow water demersal species that are found within rocky shores and tidal pools that have an abundance of algae at depths up to 15 m (50 feet). They reach a maximum of 6.0 cm (2.4 inches) in length. They feed on invertebrates. Reproduction is oviparous with females depositing eggs in protected areas. The Flapscale Blenny 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.

The Flapscale Blenny is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Guerrero Negro southward along the west coast of the Baja, along the entire east coast of the Baja and along the west coast of mainland Mexico south to the central Gulf.

The Flapscale Blenny can be confused with Longjaw Blenny, Paraclinus tanygnathus (clear caudal fin), the Pink Blenny, Paraclinus beebei (white barred anal fin), the Mexican Blenny, Paraclinus mexicanus (anal and dorsal fins with thick dark bars), and the Topgallant Blenny, Paraclinus altivelis (pink and orange head and body; anal fin with a row of dark blotches).

From a conservation perspective the Flapscale Blenny is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature, seldom seen by humans and of limited interest to most.