Fish IDReef/Wreck

Gag Grouper

Description: Brownish gray in color with dark worm-like markings on sides; strong serrated spur at bottom margin of preopercle, less noticeable in large specimens; fins dark, with anal and caudal having white margin; often confused with black grouper; most noticeable differences are brassy spots on black grouper; tail of gag is slightly concave, black grouper’s tail is square; gag has white margin on anal and caudal fins, black does not; under 10 pounds, gag’s spur on preopercle is distnctive, where black is gently rounded.

Similar Fish: Black grouper, M. bonaci.

Where Found: adults offshore over rocks and reefs; juveniles occur in seagrass beds inshore.

Size: Common to 25 pounds.

Remarks: Forms spawning aggregations in water no shallower than 120 feet in Middle Grounds area, January through March; current research to identify similar aggregations off the Atlantic coast is ongoing; young gags are predominantly female, transforming into males as they grow larger; feeds on fish and squid.