These have special features; they can live on land and in water
A rare fish species called “mudskippers” have been recorded by researchers of the Centre for Advanced Study in Marine Biology of Annamalai University at Parangipettai estuary near here.
These tiny species, measuring just 67 mm in length and weighing 22 mg, have got special features which enable them to live both on land and in water. Called ‘vaetti uluvai' in Tamil, they are the missing link between fishes and amphibians in the evolutionary ladder, according to T. Balasubramanian, Director of the Centre.
He told The Hindu that during the survey conducted recently in the Vellar estuary at Parangipettai near here under the University Grants Commission-supported project on gobiid fishes the researchers identified a mudskipper variety, Periophthalmus variabilis.
The Director said the species were aptly called mudskippers because they had mudflats as their habitat and had the habit of skipping or hopping around. The fish had got protruding rounded eyes that could move in all directions.
Its pectoral fins resembled more of the forelimbs of frogs, with which it attains mobility and climbs on to vegetations. Mr. Balasubramanian further said that the fish digs burrows in mudflats that have a gentle slope towards the sea and have a depth of up to one-and-half metre.
During high tide, the burrows would get filled with seawater and during low tide the waves would withdraw, allowing to make its appearance, he added.
Principal Investigator V.Ravi, also Assistant Professor in the Centre, said mudskippers played an important role in the food chain. They feed on fish eggs, nematodes, smaller crabs and insects, and, are, in turn, food for birds and otters. Mr. Ravi said mudskippers would lay eggs within the burrows and male fishes would oxygenate the eggs by blowing air. The eggs would not get washed away because they had an adhesive filament that made them stick to the walls of the burrows. This sensitive creature would swirl in the burrows at the very sight of a predator.
The mudskippers have medicinal quality and are being used as a remedy for anaemia and to prevent frequent urination in children.
Mr. Ravi observed that in China, South Korea and Japan the mudskippers were cultured extensively for food and the Centre would evolve a suitable strategy for its proliferation through captive breeding.