Marbled Eel - Ecology and Behaviour

Ecology and Behaviour

The adults of this species are demersal, living on the bottom of fresh to brackish waters, in rivers, lakes, and tributaries. This species and all anguillid eels are catadromous, migrating sometimes long distances out into the open ocean to spawning over deep water. A spawning area of this species is known to be west of the Mariana Islands in an area of the North Equatorial Current in the western North Pacific, but other spawning areas are thought to exist in the western South Pacific and Indian Ocean.

Marbled eels spend their adult lives in freshwater or estuarine habitats, and migrate to the ocean to reproduce. When the eggs hatch, the leptocephali drift in ocean currents for months until they reach estuaries as glass eels where they migrate upstream into freshwater as elvers. Then, after about 8 to 20 years in brackish or freshwater, the yellow eels 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 ranging diet, eating shrimp, crabs, bony fish, and frogs. It is nocturnal, so it is active at night.