Rock Sea Bass, Centropristis philadelphica
Rock Sea Bass, Centropristis philadelphica. Fish caught from coastal waters off Charleston, South Carolina, August 2018. Length: 15 cm (5.9 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.
The Rock Sea Bass, Centropristis philadelphica, is a member of the Sea Bass or Serranidae Family, and is known as cabrilla serrana. Globally, there are five species in the genus Centropristis. of which three are found in Mexican waters of the Atlantic Ocean.
The Rock Sea Bass has an elongated compressed body with a depth that is 27% to 48% of standard length. They are a pale olive-gray to brown dorsally and pale ventrally with at least seven dark brown vertical lines on their sides. Their head has blue stripes before the eyes and the tip of the jaw is purplish. Their caudal and dorsal fins are pale with several dark reddish brown or golden-brown spots and a few white spots. Their anal fin has a broad central orangish stripe. They have a large black spot at the base of the last three dorsal fin spines. They have large heads with a large mouth that has extends to the center of the eyes that has a moderately protrusible upper jaw with distinct palatine and vomer teeth. Their anal fin has 3 spines and 6 to 13 rays; their caudal fin has 13 to 15 rays and is sinuous or trilobed with the upper, middle and lower rays being elongated; their dorsal fin has 10 spines, that are tipped with short filaments, and 10 to 12 rays; and, their pectoral fins have 16 to 20 rays. The juveniles have rounded caudal fins. They have 14 to 31 gill rakers with 17 to 22 on the first arch. They are covered with scales. The lateral line is prominent.
The Rock Sea Bass is common and abundant and found both inshore and offshore over and within rocky reef as well as sand substrate at depths up to 243 m (620 feet). They reach a maximum of 30 cm (12 inches) in length with males being larger than females. They consume crustaceans, fishes and mollusks. In turn they are preyed upon by the Cobia, Rachycentron canadum. The Rock Sea Bass are synchronously hermaphroditic possessing both males and female organs and capable of producing between 1,700 and 36,000 eggs and sperm at the same time. They short lived with life spans of three years. The Rock Sea Bass 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 Rock Sea Bass is a resident of Mexican waters of the Atlantic Ocean but has a limited distribution being found along the coast of Gulf of Mexico from the United States border south and east to Campeche and the west coast of the Yucatán Peninsula.
The Rock Sea Bass is similar to and possible confused with the Bank Sea Bass, Centropristis ocyurus (black blotch at the center of the dorsal fin) and the Sand Perch, Diplectrum formosum (body with six thin blue lines).
From a conservation perspective the Rock Sea Bass is currently considered to be of Least Concern with stable widely distributed populations. They are small in stature and of limited interest to most. They are caught as a bycatch of recreational fishermen and by commercial shrimp trawlers.