The anadromous Hilsa shad (Tenualosa ilisha) live in the Bay of Bengal and migrate to the estuaries and freshwater rivers for spawning and nursing of the juveniles. This has led to two pertinent questions: (i) do all Hilsa shad that migrate from marine to freshwater rivers come from the same population? and (ii) is there any relationship between adults and juveniles of a particular habitat? To unravel the answers of the above two questions, the present study was conducted by identifying a set of neutral and adaptive genetic markers.
The hilsa is a critically important species for smallscale fishing communities in Myanmar’s Ayeyarwady Delta and Rakhine State. Yet current fishing regulations are inadequate and exploitation rates are well beyond sustainable levels. This study analyses key parameters underlying hilsa biology, comparing them across different ecological zones of the hilsa’s range in Myanmar and across time. It provides evidence of major spawning activity between July and September in the freshwater zone, particularly in September.