Jan 19, 2011

Goliath Grouper

The goliath grouper is by far the largest reef fish.  An adult goliath grouper can reach over 8 feet and weigh over 800 pounds.  These groupers are yellowish brown to olive green in color with small dark spots over their bodies and fins.  Younger goliath groupers have slight pale vertical bars along their bodies which disappear with adulthood.  If you look closely in the top video you can see the pale bars towards this youngster's tail.

The goliath grouper, or Epinephelus itajara, is a boney fish that belongs to the family Serranidae, or sea basses.  All sea basses have large mouths, lips and a jutting lower jaw.  Additionally, sea basses have a divided dorsal fin; the front half consists of spiny projections and the back half is soft and flexible.  This fish can be further classified into the genus Epinephelus, or groupers.  Groupers are the best known members of sea basses and are defined by their stocky body shape and large mouths.  They are usually solitary fish that lurk amongst reefs and wrecks. Most groupers are also protogynous hermaphrodites; they change sex from female to male as they mature.

The goliath grouper can be found along Florida's east coast, the Gulf of Mexico, throughout the Caribbean, and down to Brazil.  These groupers are found on offshore reefs and wrecks from 15 to 130 feet.  Juveniles are usually found in inshore areas, especially mangroves and brackish estuaries.  Goliath groupers feed on crustaceans such as the caribbean spiny lobster, many different reef fish, and even young sea turtles.  Most of the time these fish are large enough that they shallow their food whole.  Younger Goliath Groupers may be preyed upon by sharks, barracudas, moray eels, as well as other groupers.  The massive adults, however, have no predators.

As mentioned earlier, most groupers are protogynous hermaphrodites, meaning they change sex from female to male as they mature through their life cycle.  Goliath groupers follow this life cycle and spawn during the summer months of July, August, and September.  They form massive mating groups on certain reefs and wrecks.  In the 1980's, only ten or so Goliath Groupers would be at these spawning sites due to intense overfishing.  In 1990 capture of these creatures was banned and today 40 or 50 individuals can now be found each year at their mating grounds.

References: Humann, Paul, and Ned DeLoach. Reef Fish Identification: Florida, Caribbean, Bahamas. Jacksonville, FL: New World Publications, 2002. Print.; "Florida Museum of Natural History Ichthyology Department: Goliath Grouper." Florida Museum of Natural History. Web. 20 Jan. 2011. <http://www.flmnh.ufl.edu/fish/Gallery/Descript/GoliathGrouper/GoliathGrouper.html>.