Selective catching of "sagüiru í prata ", Steindachnerina insculpta Fernandez í Yepez, 1948 [Characiformes, Curimatidae], by employing monofilament Gill- nets, in Ibitinga Reservoir, Tietê River, São Paulo State, Brazil

Abstract

The selectivity curve equation of gill-nets employed for catching "saguiru-prata", Steindachnerina insculpta, in Ibitinga Reservoir, São Paulo State, through the model proposed by Gulland (1969), was found to be:

c* (L) = e ^{- 0.4681 (L-1.7210 m)2}

Where:

c* (L) = relative frequency of retention

L = fish total length

m = mesh internal perimeter.

The interval of selection, from minimum to maximum fish total length, for different mesh sizes (m), is done by:

L_m = 1.7210 m - 1.22 (cm)

L_M = 1.7210 m + 1.22 (cm)

The relationship between fish total body weight (W) and total length (L_t) was: W = 0.0134 L ^3.0259 (Santos, 1978).