Acta Scientiarum: Biological Sciences (Jan 2009)
Interferência de diferentes métodos de aclimatação na sobrevivência de pós-larvas de Litopenaeus vannamei (Boone, 1931) = Interference of different acclimation methods on Litopenaeus vannamei (Boone, 1931) postlarvae survival
Abstract
Observou-se o impacto de três métodos de aclimatação na sobrevivência de PL10 de L. vannamei (choque direto, diluição gradativa e gotejamento), utilizando-se águas oligohalina e doce. Para verificar alterações estruturais nas brânquias das PLs aclimatadas por gotejamento, realizaram-se análises histopatológicas e histoquímicas. A correlação entre a sobrevivência, método e tempo de aclimatação e tipos de água foram analisados usando Modelos Lineares Generalizados (p In order to observe the effects of different acclimation methods for freshwater and oligohalin water on the survival of L. vannameipostlarvae (PL10) and gills, it was analyzed three histological and histochemical studies. Three methods of acclimation were used: direct shock, gradual dilution and dripping. Three General Linear Models and Stepwise process (p < 0.05) were used to analyze the effects of methods and the time of acclimation and the different waters for dilution on survival. The survival rates were higher than 90% in the direct shock method in salinities equal or above 10‰. In the gradual dilution method the oligohalin water showed the best survival rate. In the dripping method only the time of acclimation showed a significant effect on the survival rate. The acclimation did not change the morphology of branchiae. The APS method showed a negative result and the Alcian Blue method showed positive reaction to acidglicoproteins and acidglicosaminoglicans in all postlarvae gills.Recommended method to acclimation of L. vannamei to freshwater was by dripping (48h), starting by direct shock at 10‰ salinity, and the most recommended water for acclimation was oligohalin.
