Order : Synbranchiformes
Family : MASTACEMBELIDAE
Species : Macrognathus maculatus
Maximum Length : 28 cm

The Buff-backed Spiny Eel, or Frecklefin Eel, mainly inhabits shaded streams in lowland forest, freshwater swamp forest and peat swamps, but has been locally documented in some upland areas. This species appears to be both nocturnal and diurnal.

They have a tendency to remain hidden beneath sunken leaf litter and other debris, and are often only glimpsed as they navigate from one such hiding place to another. Their movement is highly sinuous. They feed on benthic invertebrates including aquatic worms, small crustaceans and insect larvae.

Spiny eels have laterally compressed bodies and long dorsal and anal fins. They lack pelvic fins, but possess a row of short, sharp spines along the back. The colouration of the Buff-backed Spiny Eel can reportedly be quite variable.

This species ranges from parts of Indochina (Cambodia, Vietnam) through Thailand, Peninsular Malaysia and Singapore to Sumatra, Java and Borneo.

Fig 1 : Example in a shallow forest stream with sandy substrate. It was active in the daytime. Photo thanks to Serin Subaraj.

Fig 2 : Example from freshwater swamp forest in Singapore, which was active by day. The subject was briefly observed as it moved from beneath an accumulation of leaf litter to another. Just seconds after this image was taken the eel was completely hidden beneath a large leaf.

Fig 3 : Typical habitat for the species - a stream in lowland, freshwater swamp forest.


Reference : Fishbase