Investigating stingray reproductive disease

Many aquariums in the US have noticed over the years that stingrays appear to be prone to a reproductive disease that results in cystic ovaries and a fluid-engorged uterus. Symptoms include anorexia, lethargy and even death. Preliminary endocrine results suggest elevated circulating estradiol and low progestins accompany this disorder. As this is a reproductive problem, SEZARC is investigating captive and wild Southern stingrays using ultrasound and hormone analysis to better understand what causes this disease. One assay that we are working to develop will measure vitellogenin, a protein that is important for egg yolk development. Once we have figured out what causes the problem, we can work with the veterinarians to establish diagnostic parameters and then start to look at treatment options. Currently, there are no established treatment options for cystic ovaries in stingrays. This reproductive disorder has been noted in several stingray species including the Southern stingray (Dasyatis americana), cow nose ray (Rhinopterus bonasus) and the eagle spotted ray (Aetobatus narineri), so this appears to be a widespread problem. At the same time, stingrays in the wild are declining and no-one is really sure why. The Cayman Islands have an important and charismatic population of stingrays at “Stingray City” that are visited annually by thousands of tourists. As such, they are economically, as well as culturally important to the Cayman Islands. We are working with the Georgia Aquarium to help determine why the stingray population is declining, and we can use the captive stingrays to help give us information for their wild counterparts. So, this project will also support in situ conservation of stingray species.

We are working with many of the major zoos and aquariums in the US including SeaWorld Orlando, Jacksonville Zoo and Gardens, Florida Aquarium, New England Aquarium, Georgia Aquarium, North Carolina Aquariums, Minnesota Zoo, and Ripley’s Aquarium of the Smokies. To partially fund this important work, we received a Morris Animal Foundation Grant. We were also recently awarded the 2013 Florida Association of Zoos and Aquariums Outstanding Conservation Initiative for Florida wildlife.

If you are interested in supporting SEZARC studies, please contact us.