Monopterus albus, Asian swamp eel is a fresh water eel native to Asia. It is also found in Central and South America, Africa, and Australia. They are predators that are active at night, feeding on many different aquatic species. Prey species for M. albus include fish, worms, crustaceans and other small species. M. albus has an elongate body that averages from about 10-16 in. (25-40 cm) long, but can reach lengths in excess of 40 in. (100 cm). They have a blunt, rounded nose and small eyes. The tail is laterally compressed and tapers to a point. It has no scales and the fins are reduced to skin folds. It ranges from grayish-brown to greenish with the color becoming lighter towards the belly. M. albus often has darker spots along the side. They have one gill slit on the underside of their head.
Life Cycle
All M. albus begin as females and all initially mature into females. Then some of the females will develop into males. If female densities are low in a population of M. albus then these males can change back to females. It may take as long as one year for an adult to change from one sex to the other. They reproduce all year, with each female laying up to 1,000 eggs every time they spawn. The eggs float in bubble nests in shallow waters, without being attached to emergent vegetation or other surfaces.
Distribution
M. albus has been reported in Florida, Georgia and Hawaii. M. albus is considered a delicacy by many people and can be found in food markets in the United States. They can easily move to new locations because they can travel in water, can burrow up to about 5 ft. (1.5 m) deep and travel for short distances across dry land. They are nocturnal, so are rarely seen by people.
Control Efforts
A combination of management techniques including trapping, electrical barriers, and removal of vegetation may help limit the spread of M. albus to new areas. Regulations to prohibit the release of M. albus from aquariums and to prohibit deliberately stocking ponds could help slow their spreading to new areas. Prohibiting the use of juveniles as bait or dumping the bait buckets into or near any body of water would also help slow their spread to new areas.