ASPECTS OF THE REPRODUCTIVE BIOLOGY OF Aequidens tetramerus (CICHLIDAE) IN VÁRZEA AREAS OF THE MIDDLE SOLIMÕES RIVER, BRAZILIAN AMAZON

Abstract

This work investigates life strategy elements of the neotropical cichlid Aequidens tetramerus in the lakes of Central Amazon várzea, predominated by white waters. During the 2011 hydrological cycle, fish were captured monthly from banks of aquatic macrophytes present in the lakes studied. The animals found had total maximum lengths of 18.5 cm and 20 cm for females and males, respectively. The average length recorded for their first sexual maturation was 6.49 cm and 8.35 cm for females and males, respectively. Species reproduction occurred throughout the hydrological cycle, but the peak of the reproductive activity was observed during the period of rising water. The average fertility was 1,477 oocytes. The diametric distribution of these oocytes showed synchronous development in more than two groups, suggesting partial spawning. It seems that A. tetramerus reaches sexual maturation early in its life time. Based on the reproductive attributes unveiled in this study and on the fact that the species performs parental care, it is suggested that this is a predominantly K-strategist species.