Histological description and characterization of the ovarian cycle of Cryphiops caementarius (Molina, 1782) (Decapoda: Palaemonidae)/Descripción histológica y caracterización de los estados de madurez gonadal de hembras de Cryphiops caementarius (Molina, 1782) (Decapoda: Palaemonidae)

Its indiscriminate extraction and alterations of its natural environment, has put in danger of extinction the only commercial freshwater Palemonid present in Chilean inland waters. Even though this situation has awakened interest in studies which allow its controlled reproduction in captivity, currently little is known regarding basic reproductive aspects of this species. Given its relevance, this work describes and characterizes the whole ovarian cycle of Cryphiops caementarius, based on changes in external and internal ovarian morphology. Adult C. caementarius females, obtained from Limari River, were dissected and its ovaries removed and prepared for histological examinations. Fibromuscular tissue divides the ovarian tissue of each lobe into cone-shaped ovarian pouches (Maturation cones), each one containing various steps of oocytes according to the stages of ovarian development. Based on light microscopic observations of cells' sizes, morphology, and staining with H-E, the female germ cells could be classified into six different types, which include oogonia (Ov), early previtellogenic oocytes (O1), late previtellogenic oocytes (O2), early vitellogenic oocytes (O3), late vitellogenic oocytes (O4) and mature oocytes (OM). The ovarian cycle is divided into five stages based on the amount and types of oocytes present in each stage. Stage 0 and I are spawned and previtellogenesis stages. Stage II and III are early and intermediate vitellogenesis stages, while stage IV is maturity advanced stage. The presence of oogonia and previtellogenic oocytes among fully mature oocytes in stage IV reflect the capacity of the ovary of C. caementarius females to start a new full maturity cycle in a short time period.