Viability of using the pearl-net and lantern system for cultivation of Crassostrea gigas (Thunberg, 1795) in the north coast of the São Paulo State (22º25`S í 43º3`W)

Abstract

A total of 355 spats of C. gigas obtained in laboratory and fixed to broken shell substratum of 300 µm were used in this study. The cultivation was developed in longlines located in the sea of Ubatuba, São Paulo, following two steps: the first, named re-breed, from September 2, 1986 to November 5, 1986; and the second, named growing up, from November 5, 1986 to March 5, 1987. In the re-breed, 88 oyster spats with an average height of 20 mm were distributed among each layer of the pearl-nets, built in nets with 4.5 mm space among knots. At the end of the re-breed, the average growth in height was 35 mm, and cumulative survival of oyster spats was 91% . In the growing up step, 32 C. gigas specimens were distributed among each layer of the lantern, built with a net with 7.5 mm space among knots. At the end of this step, the growth was 49 mm and the cumulative survival was 63%. During this experiment, the water salinity ranged between 28 and 37% and the temperature between 18 and 30°C.