Utilização de modelos estatísticos para avaliar dados de produção do camarão Litopenaeus vannamei cultivados em águas oligohalina e salgada

Abstract

Use of statistical models to evaluate production data of Litopenaeus vannamei, reared in oligohaline and salty waters. The marine shrimp Litopenaeus vannamei may be reared in a wide range of salinity (0.5-60.0 g L-1). In this study, the production data of shrimp reared either in oligohaline (0.5-5.0 g L-1) or salty waters (25.0- 40.0 g L-1) were compared using mathematical models. The models considered variables related to management and production, and were formulated using a database with 278 culture cycles from different shrimp farms in Northeastern Brazil. The least-squares technique was applied to estimate the model’s parameters. The selection of variables used the Stepwise process associated to Box and Cox’s transformation. The adequacy of the equations and the normality estimated for the errors were analyzed on the basis of the analysis of variance in the Durbin-Watson statistics, on the residue analysis and the normality test. For all the formulated equations, the variable ‘culture in salty water’ was selected, evidencing significant differences between these culture systems.