Those who regularly watch channels such as National Geographic and Animal Planet must have noticed a black fish (not suckers) with a prominent white bar on its body swimming alongside sharks and scavenging on remnants of fish hunted by the big predator. A decade ago, Cobia ( Rachycentron canadum ) known as Black King Fish, Lemon Fish and Crab Eater, was not taken very seriously. People in Tamil Nadu would not prefer the species, which is called Kurangu Meen .
Today, it is one of the important food fishes and Chennai-based Central Institute of Brackishwater Aquaculture (CIBA) has achieved success in the controlled breeding of Cobia from pond-reared broodstock at its experimental station at Muttukadu near here.
“Cobia farming is done in cages erected in calm sea waters in countries like Vietnam. But in a country like India, where the sea is always turbulent, setting up cages is a difficult task. It is here our technology has paved a new path,” said A.R.Thirunavukarasu, Principal Investigator of the project and Head, Fish Culture Division of the CIBA.
On Monday, M. Sakthivel, former chairman of the Marine Products Export Development Authority, handed over the juveniles of Cobia to two beneficiaries.
“Ten years ago the fish was nowhere in the picture. Now it has a bright future as a commercially valuable fish,” Mr Sakthivel said.
Mr. Thirunavukarasu explained that owing to its fast growth (up to 10 kg in a year), better adaptability, excellent texture and flavour, and the fact that it fetched a good price in the domestic market and its potential for export, Cobia has been identified as a fish for diversified farming in cages and ponds in marine and brackishwater ecosystems.
Dr A.G. Ponniah, Director of the CIBA, said the fish grew very fast and the growth was quite visible.
“Since it is not easy for hatchery owners to set up cages in the sea, CIBA’s technology will enable them to rear the fish in farms,” he said.
Farmers can harvest a tonne a year from 100 juveniles while in the case of Seabass, it will require 1,000 juveniles to achieve the same result. The fish is called sea-chicken and in the market it costs around Rs. 300 per kg.
Mr. Thirunavukarasu said a Cobia would release millions of eggs during each spawning and these were fertilised externally by the male.
“At the experimental station, we keep the female and male at the ratio of 1:2 and subject them to induced spawning. For accelerating ovulation, female fish are given hormone injection. When the female releases eggs, the males fertilise them by releasing a milk-like substance,” he explained, even as workers at the experiment station caught the giant broodstock parents for displaying them to visitors.
The hatching takes place after 20-22 hours and 30 days of rearing.
The juveniles reach a length of 10 cm and can be reared in nursery and grow-out systems in cages and ponds.
