Understanding Stingray Reproductive Disease

Stingray species are long-lived, slow to mature, and produce small numbers of offspring, making them particularly susceptible to extinction threats. Reproductive disease, characterized by cystic ovaries, unovulated eggs and, often, an enlarged uterus, is prevalent in older conservation-managed female stingrays. In some species of mammals, over-conditioned (fat) females are known to have difficulty ovulating. Researchers will measure body size and nutritional markers (plasma leptin and ghrelin) in aquarium stingrays to determine whether these tests might be useful in assessing reproductive abnormalities in southern stingrays. Findings will be used to identify causal agents for stingray reproductive disease and address the overall concept of obesity and reproduction in aquatic species.