In contrast to the findings of Saavedra-Bucheli et al. (2008),we observed a highly signi
ficant dependence of decreases in the temperature that were associated with decreases in the general prevalence of Nematopsis sp. . At La Pesca, the values of the prevalence of this organism were similar in 2008 and 2009, but the temperature ranges were different (Fig. 2). We found significant correlation and determination coefficients greater than r2=0.994 (Table 3), and our results are consistent with the findings of Chakraborti and Bandyapadhyay (2011). The current study appears to be the first report that the prevalence of gregarines, namely,Nematopsis sp., is directly associated with the temperature. Because these organisms are endoparasites, it is possible that the other factors analyzed do not affect their biological
cycle, as shown by the statistical analysis (Table 3). To our knowledge, this report is the
first to analyze the effect of water quality parameters on the prevalence of the
filamentous bacterium L. mucor.Additional studies addressing variations in water quality parameters in shrimp ponds and their relationship with infectious agents and epibiont microorganisms are needed to prevent the adverse impacts on the health of the cultured shrimp. Therefore, the results of this study should help to preventing the spread of disease through the
appropriate managementof water quality in extensive, semi-intensive, and intensive shrimp cultures