The Nassau grouper is an oblong, large fish with large eyes and coarse, spiny fins. The third or fourth spine of the dorsal fin is longer than the second spine. Pelvic fins are shorter than the pectoral fins, with the insertion point located below or behind the ventral terminus of the pectoral fin base. The bases of the soft dorsal and anal fins are covered with scales and skin. Caudal fin is rounded in juveniles, convex in adults. Nassau grouper have a light, buff background color in shallow water individuals, pinkish in those from deeper water. There are five irregular dark brown vertical bars on each side and a large black saddle on the top of the caudal peduncle. The third and fourth vertical bars form a W-shape above the lateral line. A tuning fork-shaped mark is located on the forehead. Another dark band travels from the snout through the eye, curving up to meet the same band from the other side, just before the dorsal fin origin. Black dots are located around the eyes.
This grouper is common on offshore, rocky bottoms and coral reefs throughout the Caribbean region. They occur at a depth range extending to at least 295 feet, preferring to rest near or close to the bottom. Juveniles are found closer to shore in seagrass beds that offer a suitable nursery habitat. Nassau groupers are typically solitary, however, they may occasionally form schools. When threatened by predators, this fish can camouflage itself, blending in with surrounding rocks and corals.