Analysis on cultivation of oyster Crassostrea brasiliana (Lamarck, 1819) at Guarapari Station, in Cananéia-SP Laguanr-Estuarine Region

Abstract

In order to evaluate Crassostrea brasiliana growth, this bivalve was cultivated at Guarapari Station, in the Cananéia Estuary, from August 1978 to August 1979. Oyster spats previously selected were used in this experiment, with an average height of 1.96 cm, fixed in Pecten ziczac shells, with a density of 12.5 oysters/shell. A set of 20 collars, with 20 shells in each one, were arranged over an estrade of 270 x 310 cm. One collar was retired at random from the estrade every two months, in order to determine the growth in height and the survival of the oysters. From the size frequency analysis in height, for estimating the parameters from von Bertalanffy expression: L_T = L∞[1 í  e^{-k (T+t1)}], (L = height in cm, T = period of cultivation in months and t₁ = age in months), resulted in L∞ = 145 mm; K = 0.031 and average age of oysters in the beginning of the cultivation: t₁ = 5. The mortality coefficient M = 0.08 was estimated from the expression N_T = R e^-MT where: N_T = number of oysters in the instant T and R = number of oysters in the beginning of the cultivation.