Caracterização morfológica do espermatozoide e do aparelho reprodutor do Polvo-Recife-brasileiro (Octopus insularis)

Abstract

The class Cephalopoda is divided into 45 families and 140 genera. Octopus insularis, like other species of the genus, are exclusively marine animals with rapid growth, high food conversion rates, and fertility, showing great potential for aquaculture. In terms of reproduction, these animals are dioecious, exhibit seasonal spawning, with a single reproduction event (semelparity), a short life cycle, and high fertility. They have complex reproductive behavior and are capable of multiple matings, which does not necessarily result in fertilization of the female. O. insularis has a modified structure in the arm for spermatophore transfer, known as the hectocotylus. A groove is observed along the ventral region of the third arm, ending at the tip of the arm, shaped like a spoon. This modified arm (hectocotylus) is responsible for transferring the spermatophore to the female when both are mature. The present study characterized the morphology and histology of the male gonad, spermatozoa, and the integrity of the gametes' membrane in O. insularis. The animals were captured through pot fishing off the coast of Paracuru, Ceará, and taken to the Fish Biotechnology and Reproduction Laboratory at the State University of Ceará (UECE), where they were acclimatized and euthanized immediately. Subsequently, the tissues were dissected and directed to morphological analyses, and spermatophores were extracted for plasma and spermatozoa collection. The data obtained from the morphology were descriptive in nature. The percentage of plasma membrane integrity of the spermatozoa ranged from 84% to 91% for intact sperm, and for sperm with a ruptured membrane, it ranged from 9% to 16%, while the rate of sperm chromatin fragmentation was observed with a variation of 71.5% to 90% with the presence of the external halo.