Alocação de energia em peixes de duas categorias tróficas em uma área de várzea na Amazônia brasileira

Abstract

In Amazonian aquatic environments, depending on the time of year, food supply may vary and species feed on various items. This temporal condition has implications in the different ways in which the energy obtained through the feeding will be used or stored over time, affecting the survival and reproduction of the species. Considering the premise that species of fish of different trophic categories accumulate and mobilize energy in a different way, this work proposes to compare the pattern of energy allocation in fish species of two distinct trophic categories: piscivorous and detritivores. The samples were collected in a várzea area of Lake Catalão, located approximately 5 km from the city of Manaus, during the ebb / dry season (October to December) in the years 2015 and 2016. In order to catch the fish, many sizes. The captured fish were eviscerated and their tissues and organs removed and stored. Subsequently, placed the burn in a calorimetric pump to estimate the amount of calories. Caloric density in muscle, liver, cavity fat index (IGC) and hepatosomatic index (IHS) were analyzed for each sample and compared to the trophic categories. Thirty four fish specimens were captured, 56 from A. falcirostris, 22 from H. malabaricus, 16 from Serrasalmus sp. "Rob", 20 from C. meyeri, 49 from P. rutiloides and 21 from P. latior. The results showed that there is no difference in caloric density of muscle and liver between the trophic categories, the two trophic categories store energy according to the inherent pattern of each trophic group. For the IGC and IHS the results of the detritivores were smaller than for the piscivorous ones, since the piscivorous species present different reproductive strategies. Thus, our results indicate that some species use their energy reserves differently, which may be associated with different types of reproductive strategies and not the trophic category that the species belong to.