Rosy Sculpin, Oligocottus rubellio

Rosy Sculpin, Oligocottus rubellio. Fish caught from the coastal waters off Monterey, California, December 2019. Length: 7.1 cm (2.8 inches). Catch and photograph courtesy of Ben Cantrell, San Diego, California. Identification courtesy of Greg Jensen, University of Washington, Seattle, Washington.

Rosy Sculpin, Oligocottus rubellio. Fish caught from a tidal pool in Monterey, California, March 2021. Length: 7.0 cm (2.8 inches). Catch and photograph courtesy of Chris Moore, Peoria, Arizona.

The Rosy Sculpin, Oligocottus rubellio, is a member of the Sculpin or Cottidae Family, and is known in Mexico as charrasco rosado. There are five species in the genus Oligocottus, of which three are found in Mexican waters of the Pacific Ocean.

The Rosy Sculpin is reddish-brown to red and purple in color with white spotting and radiating black spokes around the eye. They are difficult to detect in their native environments as their blotchy camouflage coloration matches its surroundings. Their head has a preopercular spine with three points, which is a key to a correct identification, with 1 to 4 cirri on the end of the maxillary and a small tuft of cirri on the suborbital stay. Their anal fin has 10 to 14 rays; their caudal fin is rounded; their dorsal fin is continuous with the first portion having 7 to 9 spines and the second having 13 to 17 rays; their pectoral fins have 13 to 15 rays; and, their pelvic fins have 1 spine and 3 rays. They have 5 to 7 gill rakers.

The Rosy Sculpin is found in rocky substrates in the intertidal zone to depths up to 34 m (110 feet). They are small in stature reaching a maximum of 10.0 cm (3.9 inches) in length. They consume amphipods and polychaete worms with older larger fish also consuming crabs and shrimp. In turn they are preyed upon by a wide variety of fishes. The Rosy Sculpin 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 Rosy Sculpin is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Punta Baja, Baja California northward along the northwest coasts of Baja.

The Rosy Sculpin is fairly similar to and can be confused with a variety of Sculpins but are separated from the others by the shape of their preoperculum, and the cirri arrangements on the maxillary and suborbital stays.

From a conservation perspective the Rosy Sculpin has not been formally evaluated. They are relatively small in stature and of limited interest to most.