key west goliath grouper fishing

COMING TO GO GOLIATH GROUPER FISHING, YOU BETTER EAT YOUR WHEATIES.

Habitat

Occurring in shallow, inshore waters to depths of 150 feet (46 m), the goliath grouper prefers areas of rock, coral, and mud bottoms. Strikingly patterned juveniles inhabit mangroves and brackish estuaries, especially near oyster bars. The goliath grouper is notable as one of the few groupers found in brackish waters. This fish is solitary by nature, with the adults occupying limited home ranges. It is territorial near areas of refuge such as caves, wrecks, and ledges, displaying an open mouth and quivering body to intruders. Additional warning may be delivered in the form of the goliath grouper's ability to produce a distinctly audible rumbling sound generated by the muscular contraction of the swim bladder. This sound travels great distances underwater and is also used to locate other goliath grouper.

Distinctive Features

Goliath grouper are the largest members of the sea bass family in the Atlantic Ocean. The body is robust and elongate; its widest point is more than half its total length. The head is broad with small eyes. The dorsal fins are continuous with the rays of the soft dorsal longer than the spines of the first dorsal fin. The membranes between the dorsal fin elements are notched. Pectoral fins are rounded and noticeably larger than the pelvic fins. Bases of the soft dorsal and anal fins are covered with scales and thick skin. The caudal fin is rounded.

Size, Age, and Growth

The goliath grouper is the largest grouper in the western Atlantic. Growing to lengths of 8.2 feet (2.5 m), this grouper can weigh as much as 800 pounds (363 kg). In Florida, the largest hook and line captured specimen weighed 680 pounds (309 kg).

The oldest verifiable goliath grouper on record is 37 years. However, this specimen was sampled from a population of individuals depressed by fishing pressure and it is projected that goliath grouper may live much longer, perhaps as much as 50 years. Males achieve sexual maturity at four to six years of age and lengths of 43-45 inches (110-115 cm), females at six to seven years of age and 47-53 inches (120-135 cm). Growth rates are slow, averaging approximately four inches (10 cm) per year until the age of six years. Growth declines to about 1.2 inches (3 cm) per year at age 15, and less than .4 inches (1 cm) per year after 25 years.

Danger to Humans

Very large goliath grouper have been observed to stalk divers and even conduct unsuccessful ambushes of the same. Large individuals of this species should be treated with caution.

Food Habits

Goliath grouper feed largely on crustaceans (in particular spiny lobsters, shrimps and crabs), fishes (including stingrays and parrotfishes), octopus, and young sea turtles. Prey is ambushed, caught with a quick rush and snap of the jaws. The sharp teeth are adapted for seizing prey and preventing escape although most prey is simply engulfed and swallowed whole.

Spawning occurs during the summer months of July, August, and September throughout the goliath grouper's range and is strongly influenced by the lunar cycle. Spawning goliath grouper form impressive offshore aggregations of up to 100 or more individuals. Ship wrecks, rock ledges, and isolated patch reefs are preferred spawning habitat. In the 1980's these aggregations reached a low of less than 10 individuals per site as fishing pressure greatly impacted this species. Since receiving legislative protection the spawning aggregations of goliath grouper have risen to 20-40 individuals per location. The females release eggs while the males release sperm into the open offshore waters. After fertilization, the eggs are pelagic, dispersed by the water currents. Upon hatching, the larvae are kite-shaped, with the second dorsal-fin spine and pelvic fin spines greatly elongated. These pelagic larvae transform into benthic juveniles at lengths of one inch (2.5 cm), around 25 or 26 days after hatching.