Chennai: For the first time in India, Chennai-based Central Institute of Brackishwater Aquaculture (CIBA) succeeded in artificially breeding milkfish (Chanos chanos), locally known as "Paal Kendai" or "Poo Meen". Milkfish has the ability to grow in brackish water, seawater and even adapts to freshwater conditions.
Currently, milkfish farming in the country is carried out by collecting seeds from wild, during a small window of two months every year. It is vegetarian in feeding habits and consumes low protein formulated feed and grows upto 500-700 gram size in five to six months.
Milkfish breeds only in seawater. Juvenile fish enters brackish waters along the coasts, where lagoons and estuaries provide abundant natural diets. After attaining the somatic growth, the fish return to sea for maturation and breeding.
It was a technically challenging task to breed them out of its natural habitat. CIBA succeeded in it by induced breeding methods through hormonal manipulation - administering standardized doses of permitted hormones. The fertilised eggs obtained were then hatched and reared to fingerling stage, which were suitable for nursery rearing and farming.
"A specialized broodstock fish holding facility like large size cement tanks are required, which usually can be established in the fish hatchery for seed production," Dr. M. Kailasam, Principal Scientists (Fish and Fisheries Division), Central Institute of Brackishwater Aquaculture told Indian Science Journal.
Dr. Kailasam said with new breeding techniques developed by CIBA, milkfish can be bred for 6-8 months a year by applying hormone treatment, except monsoon season, when salinity drops below 30 ppt.
"But it requires controlled RAS (Recirculation Aquaculture System) systems to simulate natural conditions followed by hormone administration for breeding," explained Dr. Kailasam.
Milkfish which derived its name from its milk-white belly is mostly found in Pacific Ocean and to some extent in the Indian Ocean including Indian coastal waters.
It is easy to cultivate, disease resistant, high yielding, low cost, low risk with a crop period of 3 months and upwards.
Each fish can grow up to one kg size within 8-10 months period which is what makes it quite an endearing option for farmers. Also, it is widely adaptable to either seawater or fresh water. Above all it is highly sustainable, depends on vegetable-based feed and has high feed conversion efficiency. Its ability to grow with other fishes and shrimp and also disease resistant nature, is an ideal for polyculture.