A study undertaken on the gillnet selectivity of Catla catla at Aliyar
Reservoir revealed that the optimum mesh size for the commercial exploitation
of this species is 13.7 cm. Among the gillnets presently being used, the usages
of net A (mesh size 120 mm) is to be avoided to prevent the capture of immature
and maturing animals. The net B (mesh size 140mm) and Net C (mesh size
160 mm) were not found to pose any threat to the fishery. The relationship
between gilled girth(X) and fork length(Y) was found to be Y = 1.19 + 0.73
X. The technical status of the gillnets of Aliyar reservoir need to be improved
through correct attachment of floats and sinkers to enhance the catch efficiency
of the nets.