Halda is the only river in South Asia where mother fish spawn naturally
When nature breathes life in its own rhythm, the result is often extraordinary. One such marvel is the natural spawning festival of mother fish in the Halda River — South Asia’s only natural carp breeding ground.
Flowing through the Hathazari, Raozan, and Fatikchhari upazilas of Chattogram, the Halda River becomes the site of a remarkable natural event each year between April and June. During this period, indigenous carp species—Rohu (Labeo rohita), Katla (Catla catla), Mrigal (Cirrhinus mrigala), and Kalibaush (Labeo calbasu)—release eggs as part of their natural breeding cycle.
Spawning Triggered by Natural Conditions
In the final week of May 2025, on a dark new moon night marked by heavy thunder and rain, the Halda once again came alive. The extraordinary process of egg-laying began across the river.
According to Dr. Manzurul Kibria, noted Halda researcher and former chairman of the Department of Zoology at the University of Chittagong:
“During the new moon and full moon phases, heavy rain accompanied by thunder triggers flash floods in the river. That’s when the mother fish spawn. This year too, the cycle continues as expected.
A Festive Atmosphere of Egg Collection
On the night of Thursday, May 29, 2025, both banks of the river lit up with excitement. Hundreds of boats floated out onto the Halda as local fishers scrambled to collect the precious eggs. As the fertilized eggs drifted in the current, they were swiftly scooped up and preserved for future fish farming.
A Globally Rare Natural Breeding Ground
The Halda River is not just a waterway; it is a living gene bank. Among the very few rivers in the world where natural spawning of major carp species still occurs and the eggs are directly collected by humans, Halda stands out as an ecological treasure. It is not only a national heritage of Bangladesh but a rare and valuable asset for South Asian fisheries science.
