Abstract
Sand tiger sharks, Carcharias taurus, are the most common large sharks displayed in public aquariums. In the wild, female sand tigers mature at 9–10 years of age. Estimates of longevity for wild sharks are 16–17 years.1Exhibit sand tigers often live in captivity for 10–15 years with survival times reported well over 20 years after capture.2 During a relatively long life on display female sand tigers may go through many reproductive cycles. Although there have been several successful reproductive events in flow through systems around the world, there are no reports of pregnancies having occurred in the U.S. or in closed systems. Female sand tigers often drop non-fertilized eggs in the tank, but egg production and retention in reproductively unsuccessful females can lead to potentially lethal consequences. Eggs retained in one or both horns eventually become necrotic and a nidus for bacterial metritis which may lead to a septicemia and death. Septic sharks often display depression, anorexia, and diffuse dermal abscesses or draining fistulas. Metritis can be diagnosed by detecting necrotic eggs using ultrasonography, endoscopy or cannulation and uterine lavage. Antibiotic treatment alone is generally ineffective. Treatment should consist of flushing out all eggs with an antibiotic saltwater solution and appropriate parenteral antibiotics. If treatment is instituted early enough, sharks with this condition have a good prognosis.
Acknowledgements
The author would like to thank the aquarists at the Ripley's aquariums for their professional support in handling the large numbers of animals involved in this project.
References
1. Goldman K, Branstetter S, Musick J. A re-examination of the age and growth of sand tiger sharks, Carcharias taurus, in the western North Atlantic: the importance of ageing protocols and use of multiple back-calculation techniques. Environ Biol Fish. 2006;77:241–252.
2. Mohan PJ, Clark ST, Schmidt TH. Age and growth of captive sharks. In: Smith M, Warmolts D, Thoney D, Hueter R, eds. The Elasmobranch Husbandry Manual: Captive Care of Sharks, Rays, and their Relation. Chapter 15. 2004:201–226.