The Asian Swamp Eel (Monopterus albus), also known as ricefield eel, is a commercially important product associated with rice fields of East Asia and South East Asia. Francis Seow-Choen encountered one such specimen in the Nature Reserve in Singapore. It can grow to 40 cm, lacks pectoral and pelvic fins possess rudimentary dorsal and caudal fins. Skin is without scales. It has an air-breathing apparatus in its hind gut and is able to obtain air through its skin. Thus, it can survive out of water for a considerable length of time.
It is nocturnal in habit and possess tiny teeth in both upper and lower jaws. Read this account where Lee Chiu San recalls a little boy bitten by these eels and needed stitching in hospital. These teeth enable the fish to feed on aquatic invertebrates like worms, shrimps, crustaceans, insects and aquatic vertebrates like fish and frogs. The fish is in turn prey to humans and birds. This is an account of a purple heron handling a swamp eel before devouring it.
Young fish are female and a small number of them turn into males as they mature. If female population drops, some of these males can turn into females again.
Care should be taken to cook these eels thoroughly as they are known to be infected with the parasitic nematode Gnathostoma spinigerum.
The video is by Francis Seow-Choen and the photo is a video screen-grab.
References:
- Wiki account of swamp eel
- Wiki Gnathostoma spinigerum
- A guide to the Freshwater Fishes of Singapore by Kelvin KP Lim & Peter KL Ng © 1990
