Longjaw Blenny, Paraclinus tanygnathus

Longjaw Blenny, Paraclinus tanygnathus. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2021. Length: 3.1 cm (1.2 inches). Catch and photograph courtesy of Bart, The Netherlands  (worldangler.eu).

Longjaw Blenny, Paraclinus tanygnathus. Underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2023. Photographs and identifications courtesy of Ron Woheau, Zihuantanejo.

The Longjaw Blenny, Paraclinus tanygnathus, is a member of the Labrisomid Blenny or Labrisomidae Family, and is known in Mexico as trambollito adornado and blenia in Mexico. 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 Longjaw Blenny has an elongated body with a uniform depth throughout that tapers gradually at the rear into the tail. They are reddish brown with white blotches and flecks with a broad pale band behind the eyes, prominent white blotches on the pectoral fin base, and a black spot on the rear half of the dorsal fin. There anal fins are dark with clear blotches; their caudal fin is clear; and the pelvic fins are dark with white bars. Their head has a bluntly pointed snout, large eyes and lips, and cirri on the nape and branched cirri above the eyes. Their mouth is large and opens at the front. The anal fin has 2 spines and 16 to 18 rays; their dorsal fin has 26 to 28 spines of which the first 3 are elevated and followed by a deep notch and no dorsal fin rays; their pectoral fins have 12 or 13 rays; and their pelvic fins are long have 1 spine and 3 rays. They are covered with small smooth scales.

The Longjaw Blenny is a shallow water coastal species that are found within rocky shores and tidal pools covered with weedy bottoms at depths up to 15 m (50 feet). They reach a maximum of 3.5 cm (1.4 inches) in length. They feed mostly on benthic crustaceans including amphipods and isopods. Reproduction is oviparous. The Longjaw 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 Longjaw Blenny is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found only around the southern tip of the Baja and from Mazatlán to Acapulco along the west coast of the mainland.

The Longjaw Blenny is similar to six other blennies: the Flapscale Blenny, Paraclinus sini (one or two ocelli at the rear of the dorsal fin), the Leastfoot Blenny, Paraclinus ditrichus (short first dorsal spines), the Pink Blenny, Paraclinus beebei (very elongated first dorsal spine; white bars on the dorsal fin), the Mexican Blenny, Paraclinus mexicanus (short first dorsal spine), the Professor Blenny, Paraclinus stephensi (one short dorsal spine), and the Topgallant Blenny, Paraclinus altivelis (very elongated first dorsal spine).

From a conservation perspective the Longjaw 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.