A team of herpetology scientists from the University of Kerala and the Central University, Kasargode has reported the discovery of a rare eel- like fish surviving in subterranean water sources.
CSIR Emeritus Scientist Dr.Oommen V.Oommen and his team found the eels in an open well in the premises of a house at Irinjalakuda in Thrissur district. Rattled by the constant presence of what seemed to be small snakes in the water, the distraught family had abandoned the well.
“It was disgusting to see the writhing creatures in the water drawn from the well. We could not bring ourselves to use the water for cooking. Repeated flushing and treatment of the water with lime failed to solve the problem. Months later, we finally abandoned the well and informed the scientists”, says T.K.Sarafuddin, the house owner’s brother who lives next door.
The scientists who expected to find caecilians (limbless amphibians) in the well discovered Synbranchid eels instead. Villagers interviewed by the investigating team said the snakes had reappeared after every course of lime treatment and cleaning.
Descending into the 16- feet- deep well after pumping out the water, the scientists found eels coming in through the subterranean spring that served as the water source. They also collected several dead eels from the lime deposit at the bottom.
“The flat tail and gills helped us identify the creatures. Eels are not usually found in wells but a species of Synbranchid blind eels was reported recently from wells in Kozhikode and Chalakudi. However, the variety that we found at Irinjalakuda has fairly well projected eyes and is of a different colour. We are undertaking detailed taxonomical studies to identify the species”, said Dr.Oommen.
The scientists returned only after assuring the family and the villagers that the water was safe. To prove their point, they boiled the water and drank it in the presence of the villagers. The pencil- thick specimens measuring upto 20 cm in length were taken back for detailed laboratory investigation.
Known to make great migrations, the Synbranchidae family of swamp eels has around 22 species of elongate eel- like fishes and are distributed over Central and South America, West Africa, South East Asia and Australia. They occur in fresh water and marshy areas and are adapted to low oxygen environment. A blind depigmented species named Monopterus roseni was reported earlier from Kerala.
Dr.Oommen said the eels found at Irinjalakuda could probably have travelled through the subterranean spring feeding the well. “It is obviously adapted to the low oxygen environment in the water flowing so deep underground. The spring could probably be connected to a major water source like the river or canal a few kilometres away”.
On Saturday, the team was excited to find one of the live specimens surviving outside water for hours together. “Apparently, it is equipped with a dual respiratory system for an amphibious existence. That means it could be a hitherto undiscovered species. It is also significant from the evolutionary point of view”, Dr.Oommen added.
The study team included scientists from the departments of Zoology and Computational Biology and Bioinformatics, University of Kerala.
