Tadpole Clingfish, Gobiesox pinniger
Tadpole Clingfish, Gobiesox pinniger. Fish caught from a tidal pool in coastal waters of Las Conchas Beach, Puerto Peñasco, Sonora, November 2021. Length: 3.8 cm (1.5 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona. Second photo above is of the same fish taken with the fish underwater in an aquarium type setting.
Tadpole Clingfish, Gobiesox pinniger. Fish caught from a tidal pool in coastal waters of Las Conchas Beach, Puerto Peñasco, Sonora, November 2021. Length: 8.2 cm (3.2 inches). Catch and photograph courtesy of Brayden Moore, Peoria, Arizona. Identification courtesy of Chris Moore, Peoria, Arizona.
The Tadpole Clingfish, Gobiesox pinniger, is a member of the Clingfish or Gobiesocidae Family, that is also known as the Feathered Clingfish and in Mexico as chupapiedras renacuajo. Globally, there are twenty-nine species in the genus Gobiesox, of which seven are found in Mexican waters, one in the Atlantic Ocean and five in the Pacific Ocean and one, this species, in both the Atlantic and Pacific Oceans.
The Tadpole Clingfish has an elongated “tadpole” like body that are tallest and widest at the pectoral fins with broad depressed head. They are a dark green dorsally with reticulated lines and yellow spots on the front with three dark bars that radiate down from the eyes, one forward to the snout, one straight down, and one angled back. They have six oblique dark bars down the back from under the dorsal fin, interconnected and interrupted bars with streaks and spots. The anal, caudal and dorsal fins are dusky with narrow white margins or light and dark margins. Their anal fin has no spines and 10 or 11 rays; their caudal fin is rounded; their dorsal fin originates over the pectoral base and has no spines and 16 to 19 rays and a long base; their pectoral fins have 22 or 23 rays and are short and broad and form a large adhesive disk on the underside; and, their pelvic fins are fused. Their skin is smooth. They do not have scales.
The Tadpole Clingfish is a benthic species in the intertidal zone within cobble beaches and found at depths up to 5 m (17 feet) within intertidal rocky areas clinging to the underside of small rocks. They reach a maximum of 13 cm (5.1 inches) in length. They feed primarily on small crustaceans, isopods, limpets and mollusks that they pry off the rocks. They are preyed upon by rockfishes and various sea birds. Reproduction is oviparous. The have the ability to remain out of water for extended periods of time with the ability to breath air. They can also tolerate extreme changes in temperatures and salinity. The Tadpole Clingfish 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 Tadpole Clingfish is a resident of Mexican waters of the Pacific but has a limited distribution being found only within the Sea of Cortez.
The Tadpole Clingfish is most likely confused with the Bearded Clingfish, Gobisox papillifer (dorsal fin set well behind the pectoral fins); the Rockwall Clingfish, Arcos erythrops (blue spots on the head; two or three bars on the back toward the rear); and, the Smoothlip Clingfish, Gobiesox schultzi (gray body and fins; spotted pectoral fins).
From a conservation perspective the Tadpole Clingfish has not been formally evaluated but they should be considered to be of Least Concern with stable widely distributed populations. Their long-term viability is threatened by pollution and human coastal developments. They are too small to be of interest to most. Surprising, they can be caught by recreational hook and line fishermen.