Black Hamlet, Hypoplectrus nigricans 

Black Hamlet, Hypoplectrus nigricans. Fish caught from coastal waters off Caye Ambergris, Belize, June 2013. Length: 10 cm (3.9 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

Black Hamlet, Hypoplectrus nigricans. Fish caught from coastal waters off Caye Ambergris, Belize, June 2013. Length: 11 cm (4.3 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.

Black Hamlet, Hypoplectrus nigricans. Fish caught from coastal waters off Cancun, Quintano Roo, August 2013 Length: 11.5 cm (4.5 inches). Catch, photograph and  identification courtesy of Dominick Porcelli, Lighthouse Point, Florida.

Black Hamlet, Hypoplectrus nigricans. Fish caught from shore in Caye Caulker, Belize, June 2013. Length: 12.7 cm (5.0 inches). Catch, photograph, and identification courtesy of Kenneth Tse, Toronto, Ontario, Canada.

The Black Hamlet has a deep and strongly compressed body. The head has a straight profile with a relatively short snout, a protrusible top jaw, fixed teeth, and several small forward pointing spines on the lower margin of the gill covers. They vary in color and morphology from having gray bodies with translucent pectoral fins, crescent shaped caudal fin and pointed pectoral fins to darker colored with dark pectoral fins, square caudal fin and blunt pectoral fins. Their anal fin has 3 spines and 7 rays; their caudal fin is slightly lunate; their dorsal fin is continuous with 10 spines and 14 to 17 rays; and, their pelvic fins are long, reaching past the anus. They have 17 to 23 gill rakers. They are covered with small scales.The Black Hamlet, Hypoplectrus nigricans, is a member of the Sea Bass or Serranidae Family, and is known in Mexico as mero carbonero. Globally, there are eighteen species in the genus Hypoplectrus, of which fourteen are found in Mexican waters, all in the Atlantic Ocean.

The Black Hamlet is a non-migratory, solitary species that is found in waters adjacent to shallow hard and soft coral reefs at depths up to 70 m (230 feet). They reach a maximum of 15.3 cm (6.0 inches) in length. They feed on crustaceans and smaller fishes. In turn they are preyed upon by a variety of larger fishes and the juveniles are consumed by the invasive Red Lionfish, Pterois volitans. Reproduction is as synchronous hermaphrodites with individuals alternating male and female “roles” during spawning with a strategy known as egg trading. One fish acts as a female and lays a batch of eggs which the other fertilizes. The following night, the roles are reversed. They are known to also mate with the Yellowtail Hamlet, Hypoplectrus chlorurus. The Black Hamlet 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 Black Hamlet is most likely confused with the Jarocho Hamlet, Hypoplectrus atlahua (pelvic fins with blue margin) and the Yellowtail Hamlet, Hypoplectrus chlorurus. (yellow caudal fin).

The Black Hamlet is a resident of all Mexican waters of the Atlantic Ocean including the Gulf of Mexico, with the exception that they are absent from north of Tuxpan, Veracruz along the northwest coast of the Gulf, and the east coast of the Yucatán Peninsula in the Caribbean.

From a conservation perspective the Black Hamlet is currently considered of Least Concern with stable and widely distributed populations. They are small in stature and are of limited interest to most. They are utilized by the aquarium trade but only at a nominal level.