Their population is abundant in the western Atlantic from Nova Scotia to Argentina, in the Gulf of Mexico, and in the Caribbean Sea. Big fish are also referred to as “gaffers” because they must be landed with a gaff, instead of “bailed” at the stern like smaller fishĭolphins are found throughout the open ocean in tropical and subtropical waters.

They have a much more rounded head than bulls. They call adult males bulls, thanks in part to the blunt, aggressive looking forehead on bigger males. Anglers call the smaller ones peanuts or bailers. Mahi-Mahi are often called dolphinfish or dolphin, and are not related to porpoises, which are also often called dolphins. Their eyes are small and almost in line with their mouths. In Thailand, Mekong giant catfishes have been successfully bred in artificial ponds, but efforts to introduce these fish in the wild have largely failed.These fish have a single dorsal fin that runs almost the entire length of their backs, starting above the eye and ending just in front of the tail. It is now illegal in Thailand, Laos, and Cambodia to harvest the critically endangered species, though giant catfishes still are illicitly caught, with some sold to restaurants in Vietnam. Conservation effortsĬonservationists have focused on the Mekong giant catfish as a flagship species to promote conservation on the river. Overfishing is the primary cause of the giant catfish’s decline, but damming of Mekong tributaries, destruction of spawning and breeding grounds, and siltation (a process by which water becomes dirty with fine mineral particles) have also taken a huge toll. Some experts think there may be only a few hundred, or even fewer, adults left in the Mekong River. With no population figures available, estimates of the decline are based on the fall in the number of fish caught. These giant catfish were once plentiful throughout the Mekong basin, but their numbers are believed to have dropped by at least 95 percent over the past century. While scientists don’t know exactly how the fish move, the Mekong giant catfish is believed to spend much of its time feeding in Cambodia’s Tonle Sap Lake and then migrating hundreds of miles north to spawning grounds in Thailand. Highly migratory, the species requires large stretches of river and very specific environmental conditions for its seasonal journey to spawn and breed. It can reach up to 440 pounds in only six years. The Mekong giant catfish has one of the fastest growth rates of any fish in the world. After about a year, they become herbivores, and eat plants and algae. (Juveniles have barbels, but these features shrink as they age.)Īs babies, they feed on zooplankton in the river and are known to be cannibalistic. They are distinguished from other large catfish species by their near-total lack of barbels, or “whiskers,” as well as by the absence of teeth.

Gray to white in color and lacking stripes, the Mekong giant catfish has very low-set eyes, which gives it a slightly sorrowful appearance.

According to the Guinness Book of Records, a nine-foot-long individual caught in northern Thailand in 2005 weighted an astounding 646 pounds, making it the largest exclusively freshwater fish ever recorded.ĭespite its gargantuan size, but also because of it, the giant catfish lives a tenuous existence in the murky waters of its native river, Southeast Asia’s Mekong, where its numbers have plummeted so dramatically that the species is on the brink of extinction. The Mekong giant catfish is the official freshwater heavyweight champion of the world.

World record dolphin fish