Understanding Causes of Reproductive Disease in Southern Stingrays

Female southern stingrays housed in single-sex groups in multiple institutions have experienced reproductive disorders characterized by such symptoms as anorexia and lethargy and often resulting in death. Preliminary results indicate that elevated circulating estradiol and low progestin concentrations are linked with abnormal ovaries (cystic and retained follicles) and overproduction of uterine fluid (histotrophy). These researchers are studying captive and wild southern stingrays through ultrasound, hormone analysis and necropsy to determine whether reproductive disorders are a function of captive management as a single-sex group or are also present in mixed-sex groups and wild stingrays. Results will provide a useful tool for clinicians working with stingrays and will potentially provide a treatment for this disease.