The aquarium in the office of A.G. Ponniah, the Director of Central Institute of Brackishwater Aquaculture (CIBA), would be any aquarium keeper’s envy.
In it, flaunting their colours, are Spotted Scats and Sea Angels, two sought-after species of ornamental fish. And pretty soon, they may adorn many more aquariums as scientists at CIBA, Chennai, have achieved a breakthrough by breeding the two species in captivity for the first time in the country.
Both the fishes are already available in market as fish breeders and merchants collect them directly from the wild. CIBA’s achievement, however, will help ensure their availability in the market does not affect their survival in the wild or drive them towards extinction.
Scientists at CIBA have standardised the process of captive breeding of Spotted Scat (Scatophagus argus) and, are making progress in the case of Moon Fish or Sea Angel (Monodactylus argenteus), both found in brackishwater but which can be maintained in freshwater and marine aquaria.
“As far as Spotted Scat, known as Pulthatti meen in Tamil, is concerned, we have thoroughly studied the process of captive breeding and even recorded minute-by-minute development of embryo. We are in a position to breed it at any point of time,” said M. Kailasam, senior scientist at the CIBA.
The Scat is known for its fecundity, laying between 0.7 and 1.15 lakh eggs. But, even in captivity, it breeds only in saline water.
“After 18 days, they reach 5 mm in size and we can transfer and slowly acclimatize them to fresh water,” explained Dr. Kailasam, who along with the head of the department A.R. Thirunavukarasu made the captive breeding possible. Dr Thirunavukarasu is the first scientist in the country who succeeded in breeding the Asian Seabass in captivity.
They said captive breeding will save Spotted Scat from becoming extinct.
“Professional fish collectors target the natural population indiscriminately, leading to its depletion. Moreover, nets used for catching them cause injuries,” said Dr Kailasam.
At CIBA, the eggs of the Scat are released through stripping method as the fish does not spontaneously spawn in captivity.
CIBA has started supplying the fish to the market.
In the case of Sea Angel, the fish is available in plenty in Gulf of Mannar and Ennore Estuary. “Based on trials, fish were made to spawn the egg spontaneously after hormone injection and there is no need for stripping. But the larvae survived only for a week. Further research on to improve larval rearing,” Dr Kailasam said.
