O custo oxidativo da reprodução predomina em fêmeas ou machos de Semaprochilodus taeniurus?

Abstract

Long migrations are carried out by animals for various ecological purposes, with reproduction being one of the most important. During this process, the energy demand of the animal is increased, requiring adjustments at the physiological level to deal with high energy consumption, and consequent associated "oxidative stress". In order to test the "oxidative stress" as physiological cost of reproduction in females and males of Semaprochilodus taeniurus, hematological parameters, antioxidant enzyme analyzes and oxidative damage in the heart and liver of individuals were measured at the end of the reproductive migration in specimens of Semaprochilodus taeniurus collected in the Negro River, near the Lake Catalão, Amazon Basin. The hematological parameters analyzed were: hematocrit, hemoglobin concentration, number of erythrocytes and corpuscular constants (MCV, HCM, CHCM) and plasma glucose and lactate levels. Oxidative stress was indirectly quantified throughout measurements of the antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase) and, directly by measuring oxidative damage markers using the comet assay, which measures of damage levels to the DNA molecule, and the lipid peroxidation, which indicates damage to cell membrane lipids. The results showed higher values of mean corpuscular hemoglobin (HCM), glucose, glutathione-S-transferase, superoxide dismutase, lipoperoxidation and DNA damage in males compared to females. The number of erythrocytes was high in females. Based on the results, we conclude that oxidative stress was higher in males than in females, showing that, in this species of migratory fish, reproduction seems to produce a higher physiological cost in males than in females.