By Abu Siddique The Halda River — the world’s only gene bank for pure Indian carp fishes such as ruhi (Labeo rohita), catla (Labeo catla), Mrigal (Cirrhinus cirrhosus) and Kalibaush (Labeo calbasu) — has resumed hosting fish eggs in recent years, after fish eggs had all but disappeared from the river in 2016. At its height in 1941, around 4,000 kgs (8,818 lbs) of fish eggs could be found in the river, according to the Halda River Research Laboratory at the Zoology Department of the University of Chittagong. The river is also home to around 147 Ganges River dolphins, which have been categorized…