The marbled eel, also known as the giant mottled eel, is a species of eel that is found in the Indo-Pacific and African region.
It can be found from East Africa to French Polynesia north to southern Japan. In Africa, the eel may be found within Mozambique and the lower Zambezi River. The marbled eel has the widest distribution out of all the other Anguilla eels. It is usually found in tropical climates between 24Â°N to 33Â°S. There are also other regions such as the Galapagos and other Pacific regions. This is possibly associated with El NiÃ±o-Southern Oscillation events. It is not on the IUCN Red List of Threatened Species, but in some areas, such as Taiwan, it is endangered, due to extensive hunting for medicinal purposes.
Unlike other Anguilla eels, the marbled eel has a mottled color and a unique dorsal fin. The adult eels are yellow with a greenish-brown to black marbling on their back and a white belly. The elvers have less visible marbling and are grayish to yellow. The marbled eel’s large dorsal fin is different from other Anguilla eels because it’s far behind the small, rounded pectoral fin, with the origin closer to the gill opening than to the anus. The adult eels have small, oval-shaped, embedded scales. The head is rounded and the snout is depressed. The eel has thick lips, a protruding lower jaw, and its mouth ends under its eye. Its teeth are small and in bands. The eel has a robust body and a compressed tail. It has a total of 100 to 110 vertebrae. It can grow up to 6.6 ft (2 m) for males and 4.9 ft (1.5 m) for females and can weigh up to 45 lb (20.5 kg). The marbled eel can also live up to 40 years.
Ecology and Behavior
The eel is demersal, living on the bottom down to 1,300 ft (400 m). It takes at least 14 years for its population to double. The adults live in fresh to brackish water, in rivers and tributaries. The eel is catadromous, migrating long distances in the open ocean to spawning grounds. When the eggs hatch, the elvers float along the ocean current for months, living in salt water, in estuaries, and the ocean. Then, they return to freshwater. After 8 to 20 years, the elvers grow up into silver eels (mature eels), and they return back to the ocean for reproduction. The marbled eel is carnivorous, but harmless, with a wide range of diet, eating shrimp, crabs, bony fish, and frogs. It is nocturnal, so it feeds at night.
The eel is used as a source of food, and is widely cultured. Some restaurants buy live eels. In 1992, a typical 26.5 lb (12 kg) marbled eel retailed for one thousand US dollars in China. An eel habitat, Cheonjiyeon Waterfalls’ pond, is a Natural Monument in Korea.