The native freshwater eel whose scientific name is Anguilla bicolor bicolor lives most of its life in streams and rivers. It seeks the open ocean only to reproduce and give birth. At some point in their life cycle the young seek the coast and migrate up the rivers.
However, there is another eel that can be seen in some rivers usually not far from the sea. I first ran across this animal some time ago but recently found quite a lot in a couple of rivers whilst I was doing some field work in an under-developed part of Mahe.
The eel belongs to the group of fish called Snake Eels, so-called because of the shape of their body. Several species of snake eels are found on the reef environment and some are sometimes mistaken for sea snakes because of their peculiar coloring and snake-like shape.
The species that is found in the rivers can grow up to 100 centimeters and is usually olive brown in color. It is usually referred to by the name of rice paddy eel. This eel is not really a freshwater fish. Rather it is a marine and brackish-water eel that swims up freshwater streams and rivers. There are several species of fish that do this and they are known as anadromous species.
These eels can be commonly seen if one knows where to look for them. They are active usually at night where they prey on smaller fish. I have observed one take a small fiddler crab (krab semafot). They do not have very sharp teeth and therefore are not a danger to people. I have seen them living in holes in the bottom and in the banks of the rivers.
In the rivers where I found them they seem to prefer sandy, silty areas. In some countries people fish for them and use them as bait. In Asia they have been known to spawn in rice fields. In India they burrow into the sides an of paddy fields, damaging them by allowing salt water to enter.
There are many animals living in our rivers and not all of them are obvious. Some like the rice paddy eel are not well known in Seychelles because of their habits. Next time you are at a river near the coast go look for these eels. It’s worth the effort.
By Nirmal Jivan Shah, Nature Seychelles' CEO on the People Newspaper, February 16th 2006