Inland Fisheries

5.2.2.3 Migrants

The Hooghly-Matlah estuary serves as a nursery for migrant species providing spawning grounds for many, which show anadromous or catadromous types of migrations. These species can be broadly divided into four categories.

1. Marine forms that migrate upstream and spawn in freshwater areas of the estuary are: Tenualosa ilisha, Polynemus paradiseus, Sillaginopsis panijus and Pama pama.

2. Freshwater forms that migrate downstream and spawn in the sea (catadromous fishes) are Anguilla spp (Freshwater eel)

3. Freshwater species which spawn in saline areas of the estuary are: Pangasius pangasius and the prawn, Macrobrachium rosenbergii.

4. Marine fishes that spawn in the saline areas of the estuary are: Tachysurus jella, Osteogeneiosus militaris, Polynemus indicus and P. tetradactylus. These species spawn in areas where salinity ranges between 1.00 and 26.0‰. The young, after a brief sojourn, lasting a few months, return to the sea with the onset of monsoon.

The young ones of many marine species of prawns and fishes such as Penaeus indicus, P. carinatus, Leander stylifera, various sciaenids, ribbon fishes, etc. migrate for feeding into the lower zone of the estuary during the winter and summer months and return to the sea when the salinity of the estuary goes down with the onset of monsoon.

Hilsa (Hilsa ilisha ) , Gangetic whiting (Sillago panijus - tool maach), mullets (Mugil spp.) and penaeid prawns form commercially important fishery in this estuary. Of the 30 species of prawns, six species constitute commercial fishery. They are, in order of dominance, as follows: Metapenaeus brevicornis, Parapenaeopsis sculptilis, Palaemon styliferus, P. tenuipes and Macrobrachium malcolmsonii and M. rosenbergii. The large sized penaeids like Penaeus monodon and F. indicus are represented poorly. In this estuary, prawn fishery dominates the fish catches, contributing as high as 30 to 40% to the total landings. The commercially important species of the Hooghly-Matlah estuary are Tenualose ilisha, Lates calcarifer, Polynemus paradiseus, Liza parsia, L. tade, Polynemus indicus, Pama pama, Sillaginopsis panijus and prawns.