Boirali fish. Photo: EAM Asaduzzaman

Scientists at Bangladesh Fish Research Institute (BFRI) in Saidpur upazila recently developed artificial breeding technique for boirali fish -- a species that had been categorised as endangered by the government. 

Sawkat Ahmed, senior scientific officer at the Saidpur substation of BFRI, said scientific name of boirali fish is barilius barila and it belongs to cobitidae family of the species.

Pollution in waterbodies, rampant use of current nets and change in climate pushed the fish on the verge of extinction.

Also known as barali or kaksa, this popular, tasty and highly nutritious fish used to be found in abundance in natural waterbodies, ponds and swamps in the north as well as in Mymensingh and Sylhet, he added.

As part of their research, they collected five to six grams of living sample of the fish from local waterbodies in between April and May and preserved them in specialised ponds for five to six months, said Ishtiak Haider, also a senior scientific officer at BFRI in Saidpur.

At this stage, different natural and synthetic inducing agents were tested on them to evaluate breeding performance.

In breeding season, matured male and female fish were taken out of the specialised ponds and transferred to cement tanks in a hatchery where gentle water flow was ensured. Then the fish were injected with hormones.

During the research, the scientists applied specific scientific methods to develop fries of the fish through artificial insemination. In 30 to 40 days,   when the fries grow up to five to six centimetres long, they are released in regular fishing ponds. They become ready for consumption in several weeks. 

Khondokar Rashidul Hasan, chief scientist at the BFRI substation, said boirali fish can be saved from extinction through the technique that is affordable for any fish hatchery.

BFRI Director General Yahia Mahmud said the scientists at Saidpur substation was awarded by the prime minister in 2017 for their achievement in developing artificial breeding and fry producing methods for popular fish variety tengra.

Now they are conducting research to save 64 species of endangered fish varieties including bourani, khalisha, shol and taki.