Oogenesis of lithodes santolla: Histological and histochemical characterization

Abstract

Although Lithodes santolla is a resource with high commercial importance that has aroused interest in controlled reproduction in captivity, currently, little knowledge is available about basic reproductive aspects of this species. This research study describes detailed oogenesis stages at the histological level in adult females of the southern king crab of the Magellan and Chilean Antarctic Region. Oogenesis was quantitatively analyzed from the proliferation of 10-24 μm oogonia and during oocyte growth. Five stages of ovary development were identified: multiplication (0), previtellogenesis (I), vitellogenesis (II), maturity (III) and spawning (IV). Furthermore, 11 oocyte substages were distinguished: oogonia, chromatin nucleolus, early perinucleolus, late perinucleolus, oil globule, early vitellin globule, late vitellin globule, postvitelogenic, germinal vesicle migration and germinal vesicle breakdown. Primary vitellogenesis occurred in oocytes 180-185 μm, containing acidophilic globules and surrounded by a layer of thick follicle cells (20-40 μm). Secondary vitellogenesis was evident in oocytes at 315-321 with numerous acidophilic granules in the cytoplasm and surrounded by thin follicle cells; then, cortical crypts appeared, indicating the prematuration stage and preparation for ovulation. This study allows establishing gonadic changes that occur during a reproductive cycle of female L. santolla and help to strengthen aquaculture initiatives and management in the Magellan and Chilean Antarctic Region.