It can reach over 8 feet in length and weigh over 800 pounds, though most grow to roughly half that size.
Young goliath grouper tend to live in brackish estuaries, canals and mangrove swamps — especially near oyster bars. Adults generally live in shallow coral reefs to depths of 150 feet but, as seen on River Monsters, will occasionally return to their brackish and freshwater nurseries. Almost all other groupers live their entire lives in saltwater.
The Life of a Loner: Adults are solitary and highly territorial. They occupy limited home ranges and will defend areas of refuge, such as underwater caves, shipwrecks and rock ledges. When threatened, a goliath grouper will open its mouth wide, quiver its body and contract its swim bladder to produce a distinct rumbling sound.
Critically Endangered: Once prized for its flesh, the goliath grouper was hunted to near extinction. A large, inquisitive and generally fearless fish, it was no match for fishermen, who targeted the species at their spawn locations, where the fish gathered en masse every year. Today, goliath groupers are fully protected.