METABOLIC AND HISTOLOGICAL ALTERATIONS AFTER EXPOSING Deuterodon iguape TO DIFFERENT SALINITIES

Abstract

The decrease of the live bait stock for the sport fishing, in estuarine and marine environments, has stimulated studies looking for species tolerant to the different salinities. Lambari Deuterodon iguape Eigenmann, 1907 has been widely used as live bait in Brazilian estuaries has a significant market and being a native animal to Brazil, it becomes a promising substitute. In order to analyze tolerance, the objective was to evaluate routine metabolism (oxygen consumption and ammonia excretion), hematological parameters (glucose, hemoglobin and total proteins), and histological parameters (gills and kidneys) of D. iguape after exposure to different salinities. The data were evaluated according to the means and standard deviations obtained by ANOVA (one-way) analysis followed by the Tukey post-test, after verification of the normal distributions (Kolmogorov-Smirnov test) and homoscedasticity (Levene test), p<0.05. In the higher salinities (12.5) tested, increased oxygen consumption, serum glucose, hemoglobin levels, decreased ammonia and total protein excretion were observed. It was concluded that 1 hour of exposure to different salinities, changes the metabolism of D. iguape, characterized by increased oxygen consumption and decreased ammonia excretion. Changes in hematological parameters (serum glucose, hemoglobin, and total protein) are also observed in groups exposed in the higher salinities (7.5, 10 and 12.5). Gill and kidney histological alterations were classified as mild to moderate, showing that D. iguape adapted well to the saline environment, which can make its use as live bait possible in estuarine sport fishing, preserving the natural stocks of Litopenaeus schimitti shrimp.