JavaScript must be enabled in order for you to use the Site in standard view. However, it seems JavaScript is either disabled or not supported by your browser. To use standard view, enable JavaScript by changing your browser options.

| Last Updated:23/01/2020

Latest News


Swamp eel is a fish that looks and behaves more like a snake

Times of India, New Delhi, 06 April, 2015

Ananya Dutta

PUNE: This fish prefers to slink its way through mud rather than swim in the streams like other freshwater variety. The swamp eel (Monopterus indicus) may look like a snake and has adapted to burrowing habits, but it is actually a fish that can be spotted on the laterite plateaus of the Western Ghats in the monsoon.




The fish, first discovered in Robber's Cave near Mahabaleshwar, has a unique type of habitat. It has a perennial water source in a stream and the cave hosts a bat colony. The cave is full of bat guano. Surprisingly, the swamp eel not only lives in the stream full of bat guano but actually hides inside the guano mud, said Neelesh Dahanukar, INSPIRE faculty fellow at Indian Institute of Science, Education and Research (IISER), Pune.


This fish is endemic to the northern Western Ghats. It inhabits swamps and marshy areas with soft mud associated with hill streams. During the early monsoon it migrates upstream to breed and young and adult swamp eels can often be found under rocks in hill streams, Dahanukar said.


"Both adult and young eels are normally found alone or at the most two or three in number. We have never seen them in larger groups," he added.


In their natural habitat, the eels were seen in a steady position floating in water and keeping their heads on the water surface. In captivity, Dahanukar observed "air gulping behaviour" of the fish.


"This species does not breathe in water; it gulps in air at the surface and immediately dives deep inside the water. The maximum period of diving and remaining in water ranges between three and five minutes," he said, adding that preliminary observations suggest they require "free air similar to lung fish or higher vertebrates."


Studying the fish in captivity has also revealed its burrowing habits. They make several burrows in the mud lined by mucus secreted from their body that allows them to quickly retract the entire body into the burrow if they perceive a threat, he added.


During the day, some fish were found buried under boulders and hidden in hanging tree roots along the stream edges. They weren't seen foraging for food. They appear to be nocturnal as free foraging and feeding activity was observed during the night-time, Dahanukar said.


In the wild, the fish has only been observed feeding on live earthworms by creating a vacuum and sucking them in. In captivity, they also ate rotten flesh, dead loach and dried worm food. But, they were never seen tracking the prey or attacking live loaches.


The restricted geographical distribution of the fish has caused it to be listed as vulnerable in the International Union of Conservation of Nature (IUCN) red-list, but its habitat is also threatened by other pressures.


Geographical distribution: Endemic to northern Western Ghats

Population trend: Unknown.

IUCN status: Vulnerable.

Major Threats:


The fish is a delicacy in some areas like Raigad district and extensive fishing has been seen in some parts

It is sometimes killed because of its snake-like appearance

Increasing urbanization, deforestation and recreational activities in the hilly areas are a threat


The coastal plateaus are also being quarried, blasted for mango and cashew plantations, residential purposes and city garbage disposal


Some plateaus where they are found have seen the construction of windmills and in the process of building these windmills several unique habitats on the plateaus have been destroyed