- Although the flesh of the almaco jack is considered quality table fare, the species has been associated with ciguatera poisoning, a seldom fatal stomach irritation.
- The almaco jack is susceptible to tapeworm parasites in the caudal peduncle area, but the meat can be eaten safely if affected portions are cut away.
The jewfish is the largest of the grouper/sea bass family. It has a lumbering swim style, especially the larger ones. The body is yellowish brown, covered with blackish spots and dark brown splotches, including on the head and fins; these are more prominent on younger specimens. Older specimens are darker overall. Irregular dark bands run vertically along the sides of the fish. The body type is typical of other grouper: stout, deep and tapering at each end. The first dorsal fin, with 11 spines, is connected to the larger second dorsal fin, with 15 to 16 rays. This differentiates it from the giant sea bass, which has only 10 dorsal rays. The anal fin has three spines and eight rays. The opercle has three flat spines, the middle one the largest. Other distinguishing features include very small eyes, a rounded tail fin, and large, rounded pectoral fins. The number of dorsal spines can differentiate jewfish smaller than 1.5 feet in length from the spotted cabrilla; the jewfish has 11, the spotted cabrilla 10.
Jewfish are carnivores and opportunistic predators they hide in structure or cover until a food item nears, at which point they dart out to engulf the prey, and then they retreat back to their den. Jewfish eat large prey, preferring crustaceans (especially spiny lobsters) but also eating octopus, turtles, fish and stingray. They feed mostly at night.
The jewfish is found in the western Atlantic from Florida to southern Brazil, including the Gulf of Mexico and the Caribbean, and in the eastern Atlantic from Senegal to the Congo. In the eastern Pacific, they occur from the Gulf of California to Peru.
Preferring mostly shallow marine environments, jewfish live under ledges not far from shore, in estuaries, bays and harbors, mangrove areas, and coral reefs. Adults frequent dock and bridge pilings and shipwrecks, where they take refuge. Adult jewfish typically reside in waters ranging from 68 to 77 degrees Fahrenheit. They can be found at depths up to 325 feet, but usually stay between depths of 7 and 180 feet.
- Jewfish will bump and occasionally try to swallow divers who approach their hideaway.
- Jewfish meat is considered to be of excellent quality. It is finely grained, white, and has a strong flavor. During World War II it was salted, dried and sold as imported salt cod in the West Indies.