Estudo sazonal do metabolismo intermediário e do balanço oxidativo de Hyalella kaingang (Crustacea, Hyalellidae) em ambiente natural

Abstract

Currently, the execution of biological research that is able to classify and characterize the biodiversity and its ecological relations has been increasingly important and necessary in order to achieve environmental conservation. Conservation physiology is concerned about studying and qualifying many variables related to an organism, so that is possible to increase the knowledge about the functioning of a given species and to detail main environmental requirements or to establish periods of natural vulnerability. The genus Hyalella presents an American distribution and has a great importance on the food chain where it occurs, and becoming a fundamental link in processes of energy transference. The amphipod Hyalella kaingang, a very recent described species and so far not very studied, was used on this study of seasonal variation, and the objective of the present work was to analyze the metabolic behavior, the metabolic allocation, the levels of lipid peroxidation and the activity of antioxidant enzymes of the species. Thirty animals from each sex were used each season of the year, which were collected at Centro de Pesquisa e Conservação da Natureza (CPCN) Pró-Mata, located at São Francisco de Paula, Rio Grande do Sul.In the field, animals were euthanized by cryoanesthesia and in the laboratory they were homogenized in order to quantify levels of total proteins, glycogen, lipids, triglycerides, glycerol lipid peroxidation and the activity of the antioxidant enzymes superoxide dismutase, catalase and glutathione S- transferase. There was significative difference in the levels of glycogen, lipids, triglycerides, lipoperoxidation and in the activity of the enzymes superoxide dismutase and glutathione S-transferase over a full seasonal cycle in both males and females. The results of biomarkers from energetic metabolism and from oxidative stress indicate a feeding trend directed to the ingestion of proteins, and it is also suggested that the reproductive period of the species may be long-lasting, with this hypothesis being based also on the observation of pregnant females in many of the analyzed seasons. It is also suggested that there may be a reproductive peak during autumn. However, more studies must be done with this species so that the knowledge about its reproductive biology, general ecology and physiology can be increased. The present work also reinforces the idea that must be a greater interaction between different scientific fields so that a more precise profile of any given organism can be stated.