Morphological description of ovary and uterus of the nurse shark (Ginglymostoma cirratum) caught off at the Fortaleza coast, Northeast Brazil

Abstract

The nurse shark, Ginglymostoma cirratum (Bonnaterre, 1778) is one of the most studied species of elasmobranchs. However, the knowledge of their reproductive biology is still relatively rare, particularly in the western South Atlantic. This study aimed to describe the morphology of the uterus and the ovary of G. cirratum, based on specimens caught off at the Fortaleza/CE coast, northeast Brazil. Samples were collected from September 2012 to June 2013, from regular landings of artisanal fishing, which commercialize this species freely. A total of ten females were collected. The methodologies followed for analyzing the ovaries and uterus of those females included both macroscopic and histological analysis. G. cirratum has internal type ovary morphology, with invaginations of connective tissue, which defines compartments and separate oocyte groups in ovigerous lots. The epithelium lining the ovary changes from simple columnar ciliated in the area without ovigerous lots, which turns into a simple cubic epithelium in the coating portion of the epigonal organ where ovarian tissue is absent. The uterine mucosa has secretory cells denoted by Alcian Blue staining, indicating the production of mucopolysaccharides, even in immature individuals. This lecithotrophic shark has a uterine vascularized mucosa that is one characteristic of viviparous elasmobranch species.

Demographic characteristics of sharks in the sublittoral environment of the Turks and Caicos Islands

“…), together indicating that female maturity might occur at a smaller size in the TCI. Similarly, dissections of ten females from Brazilian waters revealed that the process of maturation may commence at only 152 cm TL (Rêgo et al 2019), suggesting that full maturity might also be attained at a smaller size there than has been reported from Florida (Castro 2000). In the case of males, Pikitch et al (2005) reported that male maturity occurred between 185 and 200 cm TL at Glover's Reef atoll (Belize), based on clasper condition.…”