In the Japanese/Chinese form, the males wait until the fertilised eggs hatch in their foam nests, and then keep the larvae in their mouths until they can breathe their own air.

The most widespread clade does not make foam nests, but lays the eggs among the roots of floating plants, and shows no parental care.

[6] The Asian swamp eel has a scaleless, anguilliform body that grows to a meter or less, typically 25 to 40 cm as an adult.

[citation needed] Their colour is variable, but generally olive or brown, with irregular dark flecks.

[3][7] The mouth is large and protractile, and both upper and lower jaws have tiny teeth for eating fishes, worms, crustaceans, and other small aquatic animals.

[2] M. albus is native to the tropical and subtropical areas of northern India and Burma to China, Japan, and Indo-Malayan Archipelago,[3] possible populations in Far East Russia and northeastern Australia might belong to different cryptic species.

[7] Tens of thousands of swamp eels are estimated to inhabit nearly 55 miles of two water canal systems in southern Florida, one in the North Miami area and another on the eastern side of Everglades National Park.

[15] One or more of the populations are believed to be the result of an intentional or accidental release of the creature from a home aquarium or fish farm.

Its diet includes other fish, shrimp, crayfish, frogs, turtle eggs, aquatic invertebrates such as worms and insects, and occasionally detritus.

[3] An old document from 1958 claimed M. albus is capable of moving over dry land, but many years of study found no evidence for this.

[3][7] The preferred environment for the Asian swamp eel includes a wide variety of muddy, freshwater, shallow wetlands, such as rice paddies, ditches, ponds, marshes, streams, rivers, canals, lakes, and reservoirs.

In Thailand and Vietnam, eating raw or undercooked swamp eel is the most common cause of gnathostomiasis, an uncommon parasitic disease.

[citation needed] In Balinese, the eels are known as lindung, they are sold dried in almost all village markets for use in Hindu offerings.

According to the belief of the Thai people that it will help to end suffering and sorrow, or as a merit as releasing other fish or other aquatic animals such as climbing perch (Anabas testudineus), striped snakehead (Channa striata), Chinese edible frog (Hoplobatrachus rugulosus), pond snail (Filopaludina martensi) etc.

[25] Asian swamp eels might pose a future threat to the environment of Everglades National Park, although preliminary studies reported no deleterious ecological effects in Florida.

However, more recent studies[26] in the Everglades do show several species faced precipitous declines after the introduction of swamp eels.

[3] Water-management structures near established swamp eel populations are not being opened to prevent or at least retard dispersal, particularly into the waters of the park.