Reproductive system morphology of giant barnacle “picoroco” Austromegabalanus psittacus (Molina, 1782) (Cirripedia, Balanidae)

Abstract

The reproductive structures of Austromegabalanus psittacus in two periods of sexual maturation were described. This organism is a simultaneous hermaphrodite, which transfers his sperm through an intromittent organ or penis. The male reproductive system consists of testes arranged in acini distributed in a tree-like structure, two vasa deferentia that come together to form the ejaculatory duct at the base of the penis. The female reproductive system consists mainly of a saccular ovary that surrounds the main body, which is internally organized into elongated acini bags containing oogonia and previtellogenic oocytes attached to the internal wall and free vitellogenic and mature oocyte within the lumen. Remarkable differences were observed in the ovaries between organisms collected in September and October. In September, they showed a yellowish ovary with two compact structures inside, called ovigerous lamellae with fertilized oocytes, embryos in different development stages and free nauplius in the body cavity, whereas in October the ovaries have a whitish in color and present a thick wall with a milky fluid inside.