Desenvolvimento ontogenético do poraquê Electrophorus varii (Gymnotiformes: Gymnotidae)

Abstract

Despite being broadly known by its capacity of generating strong electric discharges, little is known about the life history of the species from the genus Electrophorus, popularly known as electric eel. Among the aspects of the species biology, the development is one of the most important for the understanding of the ecological and evolutionary processes that shape the history of the organisms. In this sense, this work brings the description of the ontogenetic development of E. varii and a proposal of organization of the stages of development through the integrated analysis of the organisms. The study was realized with material from two distinct environments of the Amazon basin, where the nests were monitored by diferent periods. For the ontogenetic characterization, changes were analysed on external morphology, internal anatomy, skeletical structure and behavior of the specimens collected on the nests. We observed that the development of E. varii is peculiar and happens slowly, taking almost a year between the eclosion and the development of the juvenile aspect, without variation between the studied populations. It’s also recorded egg comsuption provided by the mother, process identified as a key process for organisms development. The study indicates the obligatory oophagy as a highly specialized provisioning strategy and highlight the importance of the in-depth ontogenetic analysis for both the proposition of a coherent staging and the understanding of inherent processes of animal development.