New methods succeed breeding endangered Chitra fish
Chitra fry were collected for research from the Shibsa River in Khulna, and canals near the Sundarbans, four years ago
In Khulna, scientists at the Paikgachha Saltwater Centre of the Bangladesh Fisheries Research Institute have been able to breed fry of the endangered saltwater fish called Chitra.
The success came recently after a continuous effort of four years.
According to the Saltwater Centre, Chitra fry were collected for research from the Shibsa River in Khulna and the canals near the Sundarbans four years ago.
Keep updated, follow The Business Standard's Google news channel
The research team led by the centre's Chief Scientific Officer Md Latiful Islam, bred the fry to become reproductive fish, getting them accustomed to conventional floating feed, in the enclosed pond of the centre.
Md Latiful Islam said the centre had been conducting research on controlled environment production of chitra fry for the last four years.
Success in the production came only after determining various factors, such as pinpointing the reproductive patterns of the fish, its breeding season, the level of salinity suitable for breeding it, and the hormones suitable for them and the dosage, said Latiful.
He said, "The hatchery now has five batches of fry. The first batch of fry is now 34 days old and the last batch is five days old. The fry are initially being fed green algae and rotifer feed. Artemia and other ready feeds are being given in phases.
"Controlled laboratory breeding of saltwater fish is more difficult than production of freshwater fish in a controlled environment. Many environmental regulators have to be considered in the breeding of saltwater fish. Moreover, live feed like algae, which is difficult to make available and maintain , is needed as primary feed for the fry."
Mizanur Rahman Wasim, senior scientific officer of the research team, said Chitra fish is omnivorous by nature and its breeding season is from April to July.
Mature fish were stimulated to breed by applying hormones in a controlled environment in the hatchery, and breeding attempts had been made since February, he said.
"Due to extreme drought this year, the maturation of the fish was delayed but with repeated efforts, the desired success was achieved," he added.
Shawn Ahmed, one of the research team scientists, said the fish is usually 35 centimetres in length and can weigh up to 1.5 kilograms.
Male fish tend to be smaller in size than female fish.
Some of the fish become fertile in the second year of life in a controlled environment, but some 80% of the fish become reproductive in the third year, he said.
At this time at the lab, the minimum weight of a male fish is 60 grams and the female fish is 180 grams. A reproductive chitra fish lays 2,000-2,500 eggs for every gram of their body weight.
The fish is known by different names in the coastal region like Paira, Bishtara and Bothra. The scientific name of the fish is scatophagus argus and is delicious to eat.
At one time, the chitra fish was found in abundance in the rivers, canals, and enclosures of the Sundarbans and adjoining coastal areas. The fish is now on the verge of extinction due to environmental disasters and lack of conservation.
Dr Yahya Mahmud, director general of the Bangladesh Fisheries Research Institute, said the Institute was proud of their achievement.
"Since the Chitra fish is omnivorous, it can be raised with other fish in the coastal area. The Chitra fish is also in high demand for use in aquariums. As new methods to breed and raise the delicious Chitra fish have been developed, production, availability, and breeding will increase at the field level," he said.
He also hoped that the success in breeding chitra fry would play a significant role in advancing mariculture in Bangladesh.
