This post was written by the Cryogenic Sperm Banking of Indian Major Carps and Exotic Carps for Commercial Seed Production and Brood Banking project team of the Feed the Future Innovation Lab for Fish and originally appeared on the Innovation Lab for Fish’s website.

Md. Anwar Hossain is leveraging cryopreserved sperm to produce quality mrigal and bighead carp. The senior assistant general manager of Biswas Agro Fisheries and Hatchery in the Mymensingh region of Bangladesh has already seen the promise of cryopreserved sperm-originated seeds (fertilized eggs). He has seen better length and weight gain of cryopreserved sperm-originated seeds than those originating from hatchery-reared males.

“I believe it is possible to develop quality broodstocks of mrigal and bighead carp by rearing cryopreserved sperm-originated seeds,” Hossain said. “My plan is to produce seeds from those broods in our hatchery.”

In 2020, aquaculture production contributed 57% of the total fish production in the country. Indian major carps, catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus cirrhosus) are the prime aquaculture species and contributed about 29% to aquaculture and 19% to total fish production. Exotic carps, silver carp (Hypophthalmichthys molitrix), bighead carp (Hypophthalmichthys nobilis) and grass carp (Ctenopharyngodon idella) also contributed 12% to aquaculture and 10% to total production.

Presently, the rate of aquaculture production has increased due to adoption of some new technologies, but has not achieved maximum production levels compared to other major fish-producing countries like China and India. Limited availability of quality seeds of Indian major carps and exotic carps, and inadequate supply to the farmers is a major problem leading to decreased production. The quality of seed has deteriorated due to inbreeding, interspecific hybridization and negative selection. As a result, fry (newly hatched fish) show slow growth, high mortality and disease susceptibility.

To resolve these commonly found issues in the aquaculture industry, a research project was started in 2020 to develop cryogenic sperm banking of Indian major carps and exotic carps. The project is funded by the Feed the Future Innovation Lab for Fish and implemented by the Department of Fisheries Biology and Genetics at Bangladesh Agricultural University.

In the 2021 breeding season, there was successful breeding of rohu, mrigal, silver and bighead carps in two public and seven private hatcheries. Both cryopreserved and fresh sperm-originated seeds were reared separately in the nursery ponds of the respective hatcheries. To compare the growth rate, length and weight data of the fish, fry were taken on a monthly basis from every nursing pond.

“I am happy to see that the growth rate of cryopreserved sperm-origin fry is much more than those from fresh sperm-origin of silver carp in my hatchery,” said Md. Abdul Alim, the owner of Mukteshowri Fish Hatchery in Jashore. “I am hopeful that quality seeds and broods can be produced by this technology, and I am interested in breeding other species with cryopreserved sperm during the next breeding season.”

In Matri Fish Hatchery in Jashore, rohu, mrigal and silver carp were bred successfully by cryopreserved sperm, as well as fresh sperm.

Jahidur Rahman, owner of the hatchery, said, “Since the growth of cryopreserved sperm-originated fry in my hatchery is much higher than those of fresh sperm, we are rearing those fries carefully, so they become good quality broods.”

Md. Abu Nasar Sardar, owner of Suriya Nur Matsha Hatchery in Rajbari, also had fruitful results from using cryopreserved sperm.

“I got better results than control sperm,” he said. “Thanks to this, I am rearing 100 bighead carp fingerings with special care for producing broods.”