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 is square; gag has
white margin on anal and caudal fins, black does not; under
10 pounds, gag's spur on preopercle is distinctive, where
black is gently rounded.
fish: Black grouper, M.
bonaci; Yellowfin grouper,
M. venenosa; other grouper.
found: adults offshore over rocks and reefs; juveniles
occur in seagrass beds inshore.
common to 25 pounds
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.