Hilsa forms a single large inland fishery. Immature hilsa, known as 'jatka', are fished extensively in rivers near Chandpur between February and May. This indiscriminate fishing of 'jatka' is detrimental to the hilsa fishery. Hence, 'jatka' needs to be protected. Large-sized fish mainly contribute to the monsoon fisheries (May to October) and smaller individuals form the fishery during the winter months (November to January). Genetic research (population genetics) for the aquaculture sector is being done in the country (Ref. 55327). Also Ref. 188.