Please ... don't encourage people to eat hilsha .. if demand for this fish rises, none of these fish will be left to eat. And these fishes are sea fish, come to the river to lay egg. They are not able to be produce commercially in the pond. Even Bangladesh is face shortage of these.
Nice and interesting topic you have posted. No only in Bangladesh, in west Bengal and Orissa, the fish is called as "Ilisha", and its curry is very testy.