Consumo de oxigênio e fluxo iônico de ovos e larvas de tambaqui, Colossoma macropomum Cuvier, 1818 (Characidae, Serralminae) em diferentes temperaturas

Abstract

The main goal of this study is the analysis of metabolic changes during the ontogeny of tambaqui, Colossoma macropomum. Thus, we have analyzed the oxygen consumption, the total hardness, and the flux rates of Ca, Mg, Na and K at different embryonic and larval stages of tambaqui. Temperature influences on these parameters were also analyzed. Changes in oxygen consumption, total hardness, and Ca, Mg, and Na flux rates were observed during the embryonic and larval stages of tambaqui. Temperature changes between 24 and 30°C did not affect these parameters. Changes in total hardness, Ca and Mg flux rates were similar in all developmental stages, suggesting similar osmoregulatory properties of these ions. The K flux rate was not altered during the embryonic and larval development but it changed in eggs and larvae exposed to 24 and 30°C. The effluxes of the analyzed ions suggest that ion poor water is not recommended for the initial development of tambaqui. This study represents an addition to the scarce literature related to metabolism aspects of tropical fish, in particular during the transition from egg to larvae.