Abstract

The injection of exogenous hormones has been proofed to stimulate the ovary maturation process in different species. However, previously it is necessary to know the dynamics of the process of ovary maturation, and to characterize the different stages of it. The present study characterizes the ovary maturation process of the spiny rock lobster Jasus frontalis using light and scanning electron microscopy. The ovary of this species is distinguished by having an external layer of loose connective tissue and a strong muscular wall with inner muscular partitions and filamentous extensions that reach the basal lamina of the follicles. It has an unusually well developed system of hemolymphatic vessels within the muscular wall and extensions of it, and produces extensive amounts of collagen fibers throughout the ovary as maturation of oocytes progresses. The inner epithelium of the ovary is modified for various functions in its different regions, serving a germinative function within the ovary, and a secretory function near to, and within the oviduct. Along the core of the ovary a germinative cord is extended, with oogonia and previtelogenic oocytes. From this cord, extensions to the ovary wall arise, containing vitellogenic and mature oocytes. It determines a proliferation zone near to the connection with the oviduct. The organization of a network of criss-crossed muscular fibers of the wall and the extensions, suggests an active participation of the muscular wall in the oocytes extrusion from the ovarian follicles, and a posterior efficient translocation of the oocytes to the oviduct. A concomitant action of a collagenase to hydrolyze the collagen fibres of the mature follicles during the ovulation is suggested. Unlike homarid lobsters, this species ovulates and spawns almost simultaneously, but it has numerous features in common with the Palinuridae family and other crustaceans.