May be . Through you I have come to know the exact name . i have no more idea about this fish . Actually It is known as helicopter fish among my local area and hooghly ,bardman district . Some months ago I did not know about this fish . Recently I started to live in bardmam .When my father caught this fish , local public said to us that It is helicopter fish and it is known as helicopter . Thanks for sharing and for actual information . From next time I will not eat this fish . As a fish lover , we ate this fish first time.