Efeito da maturação gonadal sobre o conteúdo calórico e condição geral de peixes da planície de inundação do alto rio Paraná

Effect of gonadal maturation on the caloric content and general condition of fish from the upper Parana river floodplain. Aiming to investigate the energy allocation and the correlation between it and the condition factor (K) of fish from the Upper Parana River floodplain (22o43'S; 53o2'W), the following species were selected: Serrasalmus marginatus (piscivorous), Loricariichthys platymetopon (detritivorous), Leporinus friderici (omnivorous-herbivorous) and Parauchenipterus galeatus (omnivorous-insectivorous). The collections were carried out in November/2002 and March and September/2003. The muscle samples of individuals from both sexes, belonging to different stages of gonadal maturation had their caloric content determined in a calorimetric pump and the results compared with K. Significant differences were found between the sexes and maturation stages. The detritivorous species was positioned between the omnivor and piscivor regarding the caloric content. Differences among the omnivorous were not identified. The gonadal maturation had an effect on the allocation of energy and K. It was not correlated with the energy stored in the muscles.