The Halda River wore a festive look as brood fish (mother fish) of some indigenous sweet water fish species released eggs for the first time in the current season early Friday.
Noted Halda River researcher Prof Dr Manzoorul Kibria told the Dhaka Tribune that the brood fishes started releasing eggs around 1:30am on Friday to test the congenial aquatic environment.
“The local spawn collectors started collecting eggs from 2:30pm in the river which is the largest natural spawning ground for carp fish in the country,” said Prof Kibria.
The spawn collectors, experts and fisheries officials said different natural factors like temperature of water, strong currents and thunderstorms create a congenial atmosphere for the mother fishes to lay eggs in the river.
Immediately after the brood fishes had released eggs, several hundred spawn collectors started collecting eggs from different points of the river.
This year, the brood fish released the highest quantity of eggs compared to the past four or five years, said several spawn collectors.
Prof Kibria said: "This time, some 400 spawn collectors were deployed to collect eggs. Primarily, we have learnt that the spawn collectors collected 22,680kg of eggs. Last year, they collected 1,680kg of eggs.”
“Usually, the brood fishes release eggs on a trial basis at first. The mother fishes spawn finally if they find the aquatic environment congenial for laying eggs," said district fisheries official Md Mominul Haque.
“At the beginning of April, indigenous fish species migrate from different rivers to the Halda to spawn. The river wears a festive look when the egg collectors start their work.
“After spawning, the brood fishes usually remain weak for sometime, due to which the fisheries staff remain vigilant so that none could net the spent fish in the river,” Mominul added.
During the Bangla months of Boishakh and Joishtho (April and May), different species of mother fish, such as Katla, Ruhi, Mrigal and Kalbaoush start migrating to the spawning ground of the Halda from Karnaphuli, Matamuhuri and Sangu rivers.
The Halda, which flows through Hathazari and Raozan upazilas of Chattogram, is considered as the only natural breeding ground in the world where these species of fish release their eggs at a certain period of the monsoon. Fry collectors catch those eggs through a unique method to sell it to the fish farmers across the country.
After collecting the eggs, the fishermen nurture the eggs in mud pots and also in cisterns of different hatcheries set up by the Fisheries Department. After 96 hours, the eggs usually transform into fries which are then sold out to the fry collectors or hatchery owners.