Atlantic goliath grouper (Epinephelus itajara)

Also known as: black bass, esonue grouper, giant seabass, goliath grouper, guasa, hamlet, jewfish, southern jewfish, spotted jewfish
Synonyms: Promicrops ditobo, Promicrops esonue, Promicrops itajara, Serranus galeus, Serranus guasa, Serranus itajara, Serranus mentzelii, Serranus quinquefasciatus
  
French: Mérou Géant, Têtard
Spanish: Cherne, Guato, Guaza, Mero Batata, Mero Pintado, Mero Sapo
KingdomAnimalia
PhylumChordata
ClassActinopterygii
OrderPerciformes
FamilySerranidae
GenusEpinephelus (1)
SizeLength: up to 2.5 m (3)
Weightup to 360 kg (3)

The Atlantic goliath grouper is classified as Critically Endangered (CR) on the IUCN Red List (1).

The Atlantic goliath grouper (Epinephelus itajara) is one of the largest members of the sea bass family. Its body is large and stocky, measuring half as wide as it is long. The head is broad with small eyes and the pectoral fins and tail fins are rounded. The first and soft dorsal fins are joined together along the back of the fish, and the bases of the first dorsal fin and anal fin are covered with scales and thick skin (2) (3).

Atlantic goliath groupers are dull green, grey, or dark yellow to brown, with small dark spots on the head, body and fins. Smaller individuals of less than one metre long are more decorative, with three or four faint vertical bars on their sides. Juveniles are tawny-coloured with dark banding and blotching. This predatory fish has several rows of small teeth in the jaw and small ‘pharyngeal’ teeth (2) (3).

The Atlantic goliath grouper is found in the eastern Atlantic Ocean from Senegal to Congo, as well as in the western Atlantic Ocean from Florida to Brazil, including the Gulf of Mexico and the Caribbean Sea. It is reportedly rare around the Canary Islands (2) (4).

A separate population of goliath groupers in the eastern Pacific Ocean has now been classified as a separate species, the Pacific goliath grouper (Epinephelus quinquefasciatus) (1).

This marine fish inhabits shallow, inshore waters with mud, rock or coral bottoms and is infrequently found below depths of 46 metres. Juveniles inhabit mangroves and associated structures for the first four to six years of their lives, then move to offshore reefs when they reach about one metre in length (3). Adults prefer structured habitat, such as rocky ledges, caves, and ship wrecks (1) (2) (3) (4).

The Atlantic goliath grouper may be solitary or occur in groups of up to 50 or more individuals. Its home range appears limited and the fish produces a booming sound when threatened by divers or large sharks. Variations of these vocalizations also undoubtedly have intraspecific communicative properties (3).

During the breeding season, from July through September, Atlantic goliath groupers gather together at breeding sites in groups of 100 individuals or more, for periodic spawning. The fertilised eggs are scattered in the water column and develop into kite-shaped larvae with long dorsal fin spines and pelvic fin spines (2) (3). About a month or more after hatching, the larvae mature into juveniles of just 2.5 centimetres long and settle preferentially into mangrove habitat (2) (3).

These fish are very long-lived, with a slow growth rate and late sexual maturation. Males begin breeding at four to six years and females mature at six to seven years. However, if the Atlantic goliath grouper is like most other groupers, it may undergo a sex-change part way through life, starting out as a female and becoming male at some later time, although this has never been observed in this species (2).

The Atlantic goliath grouper feeds on crustaceans, such as spiny lobsters, shrimps and crabs, as well as fish including stingrays and parrotfish, in addition to octopuses and young sea turtles. Despite having teeth, the fish engulfs its prey and swallows it whole. Before the Atlantic goliath grouper reaches full size it is susceptible to the attack of barracuda, king mackerel and moray eels, as well as sandbar sharks and hammerhead sharks (2). Once it is fully grown, humans and large sharks are the Atlantic goliath grouper’s only predators (2) (3).

The Atlantic goliath grouper is particularly prone to over-fishing because of its large size, slow growth rate, low reproductive rate and group spawning activity. The fish has excellent quality flesh and has been at risk of spear-fishing for recreation and sport (2) (4).

During the 1980s there was an observed reduction in numbers within spawning aggregations of the Atlantic goliath grouper, dropping from over 100 individuals per location to fewer than 10 individuals, and numbers were suspected to have been reduced by 80 percent. This prompted legislative protection preventing fishing of this species. In the ten years following the implementation of the legislation, numbers of individuals in each spawning aggregation rose to between 20 and 40 individuals (2).

Find out more about the Atlantic goliath grouper:

Authenticated (04/07/2006) by Dr. Chris Koenig, Florida State University Coastal and Marine Laboratory (FSUCML); and member of the IUCN/SSC Grouper/Wrasse Specialist Group.
http://www.marinelab.fsu.edu/faculty/koenig.html

  1. IUCN Red List (February, 2013)
    http://www.iucnredlist.org/
  2. Ichthyology Department, Florida Museum of Natural History - Goliath grouper (October, 2004)
    http://www.flmnh.ufl.edu/fish/Gallery/Descript/GoliathGrouper/GoliathGrouper.html
  3. Koenig, C. (2006) Pers. comm.
  4. FishBase - Epinephelus itajara (February, 2013)
    http://www.fishbase.org/summary/Epinephelus-itajara.html