Efeito conjunto da salinidade, densidade de estocagem e tempo de troca de água, sobre o crescimento e sobrevivência larval da ostra-do-mangue, Crassostrea rhizophorae (Guilding, 1828)

Abstract

This paper reports the combined effects of salinity, stocking density and frequency of water exchange on the growth and survival of Crassostrea rhizophorae from fi rst to 6th day (trial 1) and 7th to 14th day of development (trial 2). Two salinities (25 and 35) and three densities (3, 6 and 12 larvae ml-1 in trial 1; and 2, 4 and 8 larvae ml-1 in trial 2) were tested at three different frequencies of water exchange (24, 48 and 72 h). Larvae reared in the salinity of 35 showed the highest survival in trial 1, but it was not signifi cantly different from the salinity of 25 with water exchange of 72 h. In the second trial, survival was higher in the salinity of 25. Growth was higher in both trials in the salinity of 25. Overall, water exchanges of 48 and 72 h signifi cantly improved growth and survival. Stocking densities had no signifi cant effect on individual length, but its height was improved at 3 and 6 larvae ml-1. Survival was higher at 6 (33.13%) and 12 (36.22%) larvae ml-1 in trial 1 and at 2 (16.69%) larvae ml-1 in trial 2.