Gag Grouper, Mycteroperca microlepis

Gag Grouper, Mycteroperca microlepis, Juvenile. Fish caught out from coastal waters off  Big Pine Key,  Florida, April 2020. Length: 18 cm (7.1 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.

Gag Grouper, Mycteroperca microlepis, Juvenile. Fish caught from coastal waters off the Sanibel Island, Florida, February 2017. Length: 22 cm (8.7 inches). Catch, photograph and identification courtesy of Marc Eberlein, Grand Rapids, Michigan.

Gag Grouper, Mycteroperca microlepis, Juvenile. Fish caught from coastal waters off Key West, Florida, August 2014, Length: 36 cm (14 inches). Catch, photograph and identification courtesy of Dean Kimberly, Atlanta, Georgia.

Gag Grouper, Mycteroperca microlepis. Fish caught from coastal waters off Clearwater, Florida, March 2012, Length: 51 cm (20 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

Gag Grouper, Mycteroperca microlepis. Fish caught from coastal waters off Clearwater, Florida, March 2012, Length: 76 cm (2 feet 6 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.

The Gag Grouper, Mycteroperca microlepis, is a member of the Grouper or Epinephelidae Family, and is known in Mexico as abadejo. Globally, there are fifteen species in the genus Mycteroperca, of which eleven are found in Mexican waters, seven in the Atlantic and four in the Pacific Ocean.

The Gag Grouper has an oblong-shaped body, that vary in color depending on maturity and sex. Juveniles and mature females are pale to brown-gray with dark blotches and worm-shaped markings affording them a marbled appearance. Their anal, caudal, and dorsal fins have dark blue-black margins. Large males are overall pale to medium gray with very limited markings below the dorsal fin and dark gray to black ventrally. Their anal and caudal fins have white margins and their caudal, soft dorsal, pectoral, and pelvic fins are dark gray. They have long heads with a large mouth featuring a protruding lower jaw and two large canine teeth at the front. Their caudal fin is large and concave.

The Gag Grouper is found in both brackish and offshore marine waters within rocky bottoms at depths up to 152 m (500 feet). They reach a maximum of 1.45 m (4 feet 9 inches) in length and 36.5 kg (80 8 oz) in weight. As of January 1, 2024, the International Game Fish Association world record for weight stood at 36.5 kg (80 lbs 8 oz) with the fish caught from coastal waters off Destin, Florida in October 1993. The corresponding record for length stood at 89 cm (2 feet 11 inches) with the fish caught from coastal waters off St. Augustine, Florida in August 2014. They are either solitary individuals or found in groups of 5 to 50 individuals. They are voracious predators feeding on cephalopods, crabs, fish and shrimp. In turn they are preyed upon by sharks and other large fish; juveniles can also fall prey to cannibalism by the adults. They are protogynous hermaphrodites with females changing to males at mid-life. Spawning occurs in the spring with fertilized pelagic eggs hatching within 48 hours of release. They have lifespans of 16 years. The Gag Grouper 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 Gag Grouper is a resident of all Mexican waters of the Atlantic Ocean including the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean.

The Gag Grouper can be confused with the Black Grouper, Mycteroperca bonaci (caudal fin with straight margin; dark fin margins).

From a conservation perspective the Gag Grouper is currently considered to be VULNERABLE as they are a rare, long-lived, and large species with slow reproduction cycles and growth rates and subject to overfishing. As such they are facing a high risk of extinction in the wild in the medium-term future. They are a targeted species of both recreational and commercial fishermen that experience heavy fishing pressure during spawning periods. The result is a significant decline in mature males with current male populations are thought to be inadequate to maintain the species. They are caught with hook and line and marketed fresh. They are known, however to contain ciguatoxin. Immature juveniles are also taken in abundance as a by-catch of shrimp fishermen.