Squarespot Rockfish, Sebastes hopkinsi
Squarespot Rockfish, Sebastes hopkinsi. Fish caught from coastal waters off Santa Rosa Island, California, August 2019. Length: 18 cm (7.1 inches). Catch, photograph, and identification courtesy of Kenneth Tse, Toronto, Canada.
Squarespot Rockfish, Sebastes hopkinsi. Fish caught from coastal waters off San Diego, California, October 2014. Length: 18 cm (7.1 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.
Squarespot Rockfish, Sebastes hopkinsi. Fish caught from coastal waters off the Channel Islands, California, August 2019. Length: 19 cm (7.5 inches). Catch, photograph and identification courtesy of George Brinkman, Guelph, Ontario, Canada.
Squarespot Rockfish, Sebastes hopkinsi. Fish caught from coastal waters off Ejido Eréndira, Baja California, February 2015. Length: 26 cm (10 inches). Photograph courtesy of Chris Wheaton, Fullerton, California.
Squarespot Rockfish, Sebastes hopkinsi. Fish caught from coastal waters off Tijuana, Baja California, February, 2023.. Length: 72 cm (28 inches). Catch, identification and photograph courtesy of Luke Ovgard, Klamath Falls, Oregon.
Squarespot Rockfish, Sebastes hopkinsi. Fish provided by the commercial fishermen of the greater San Diego area, San Diego, California, October 2014. Length: 29 cm (11 inches). Identification courtesy of Milton Love, University of California, Santa Barbara, Goleta, California.
The Squarespot Rockfish, Sebastes hopkinsi, is a member of the Rockfish and Scorpionfish or Scorpaenidae Family, and is known in Mexico as rocote a cuadros. Globally, there are one hundred eight species in the genus Sebastes, of which fifty-three are found in Mexican waters, all in the Pacific Ocean.
The Squarespot Rockfish has an oval-shaped body with a depth that is 32% to 36% of standard length. They lack the head spines found in the majority of rockfish. They have a yellow-brown to tan coloration with subtle saddles on their back and head. Some have a dark sideways V-shape marking on their gill cover behind each eye. This marking tends to fade post collection with the fish becoming uniform in color. A key to identification is a dark “mustache” line on their upper lip. Their fins are generally dark with the anal and pelvic fins being lighter and the caudal fin being darkest. Their head is of medium length with relatively small eyes and a small terminal mouth. Their anal fin has 3 spines and 6 to 8 rays; their caudal fin is slightly lunate; their dorsal fin has 12 to 13 spines and 13 to 17 rays; and, their pectoral fins have 16 to 18 rays. They have 35 to 43 gill rakers and their body is covered with scales.
The Squarespot Rockfish is a schooling species found from mid-water to the bottom over rock substrates at depths up between 18 m (60 feet) and 305 m (1,000 feet). They are active during daylight hours and take cover at night. They reach a maximum of 29 cm (11 inches) in length, with females being larger than males. They are known to school with Pygmy Rockfish, Speckled Rockfish, and Widow Rockfish. They feed primarily on invertebrates including copepods, krill, and other zooplankton. Reproduction is oviparous with each female releasing between 9,000 and 39,000 pelagic eggs. They have a lifespan of up to 19 years. The Squarespot Rockfish 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 Squarespot Rockfish is a resident of Mexican waters of the Pacific but has a limited distribution being found from San Quintin, Baja California, northward along the northwest coast of Baja.
The Squarespot Rockfish is most likely confused with Bank Rockfish, Sebastes rufus (body covered with small black spots), the Speckled Rockfish, Sebastes ovalis (body covered with speckles), and the Widow Rockfish, Sebastes entomelas (lacks mustache on upper lip).
From a conservation perspective the Squarespot Rockfish has not been formally evaluated. They are not an important commercial species, however, with the decline of the larger Rockfish populations they are now being taken more frequently by recreational anglers but are generally too small to be of interest and thus are normally discarded.