(Selectivity curve of Gill-nets and dimensions of the mesh size for catching corvina Micropogonias furnieri (Desmarest, 1823)

Abstract

The main objective of this work was to determine the mean selectivity curve of gill-nets for catching corvina Micropogonias furnieri (Desmarest, 1823), captured in the lagoon of Cananéia (SP), and estuarine bay complex of Santos (SP), through the model proposed by Gulland (1971). The results indicate that the selectivity of these nets can be represented by:

c*(L) = e^{-0.016 (L í  1.92 m)2}

where:

c*(L) = relative frequency of retention

L = total length of the fish

m = perimeter of the mesh.

The interval of selection for different mesh sizes is given by:

Lm = 1.92 m-6.6 (cm) e LM = 1.92 m + 6.6 (cm).

The coefficient k used to determine the optimum mesh size was calcu1ated according to Baranov, quoted by ANDREEV (1966), and found to be 0.13. The data permitted a1so to conc1ude that most fishes are retained in the nets in the post orbita1 1ength.