Blackfin Snook, Centropomus medius
Blackfin Snook, Centropomus medius. Fish caught from coastal waters off Puerto Adolfo Lopez Mateos within the northern portion of the Magdalena Bay complex, Baja California Sur, November 2023. Length: 28 cm (11 inches). Catch, photograph and identification courtesy of Chris Wheaton, Fullerton, California.
Blackfin Snook, Centropomus medius. Commercial fish purchased at Soriana’s Mercado, San José del Cabo, Baja California Sur, December 2019. Length: 30 cm (12 inches).
Blackfin Snook, Centropomus medius. Fish caught from coastal waters off Las Animas within the northern portion of the Magdalena Bay complex, Baja California Sur, December 2021. Length: 48 cm (19 inches). Catch, photograph and identification courtesy of Brad Murakami, Surrey, British Columbia, Canada.
Blackfin Snook, Centropomus medius. Fish caught from within the estuary of the northern portion of the Magdalena Bay complex, Baja California Sur, November 2022. Length: 51 cm (20 inches). Catch and photograph courtesy of Jonathan Wexler, Denver, Colorado.
The Blackfin Snook, Centropomus medius, is a member of the Snook or Centropomidae Family, that are known locally as paletas and in Mexico as robalo aleta prieta or just robalo. Globally, there are twelve species in the genus Centropomus, and all twelve are found in Mexican waters, six in the Atlantic and six in the Pacific Ocean.
The Blackfin Snook has an oblong elongated compressed body. They are silvery fish with a prominent dark lateral line. Their anal fin is transparent with a black membrane between the second and third spines; their caudal fin is transparent with a black lower lobe; their dorsal fin is transparent with a black membrane between the second and third spines; their pectoral fins are transparent with a black fin base; and their pelvic fins are transparent. Some fish have pelvic fins with black outer rays. They have a slightly concave shovel-shaped upper head profile, with a large protractile terminal mouth, a protruding lower jaw, and large eyes. Their anal fin has 3 spines, the second is thicker than the third but equal in length, and 5 to 8 rays; their caudal fin is deeply forked; their first dorsal fin has 8 spines with the third being longer than the fourth; their second dorsal fin has 1 spine and 8 to 11 rays; their pectoral fins are shorter than the pelvic fins; and, their pelvic fins are inserted behind the pectoral fins.
The Blackfin Snook is found in bays, estuaries, the lower parts of freshwater streams, and where dry river beds meet the ocean (presumably due to subterranean water flow) at depths up to 24 m (80 feet). They reach a maximum length of 56 cm (22 inches) and weigh approximately 3.0 kg (6 lbs 10 oz). As of January 1, 2023, the International Game Fish Association world record stood at 3.2 kg (7 lbs 0 oz) with the fish caught in coastal waters off Costa Rica in January 2002. The Blackfin Snook 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 Blackfin Snook is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Magdalena Bay, Baja California Sur, southward along the southwest coast of Baja, in the southern half of the Sea of Cortez, and along the coast of the mainland south to Guatemala. They are more abundant in the southern portions of this range.
The Blackfin Snook is most likely confused with the Black Snook, Centropomus nigrescens and the White Snook, Centropomus viridis (third dorsal spines much longer than first and second in both fish).
From a conservation perspective the Blackfin Snook is currently considered to be of Least Concern with stable, widely distributed populations. They small and fairly rare, thus not of significant interest to most, but they can be found with the local markets within the greater Los Cabos area of Baja California Sur. Due to their white meat, they are considered an excellent food fish.