Assessing reproductive potential and gestation in nurse sharks (Ginglymostoma cirratum) using ultrasonography and endoscopy: An example of bridging the gap between field research and captive studies

Over a period of 3 years, five reproductively active female nurse sharks (Ginglymostoma cirratum) from a wild, actively mating population of nurse sharks were captured, confined, and periodically examined through the course of gestation to determine the gestation period and characterize paternity. In the final year of the study, candidate animals were first evaluated in the field by ultrasonography, and the selected animals were then transported from the study site to holding facilities at SeaWorld Adventure Parks in Orlando, Florida. Periodic monitoring of the animals was conducted by ultrasonography, endoscopy, and routine blood analysis. Gestation was determined to be a minimum of 131 days, multiple paternity was shown for two individual litters, and ultrasonography and endoscopy were shown to be useful adjuncts for assessing pregnancy and monitoring gestation in this species. Poor survival of offspring, and small litter size may be a consequence of handling and transporting the animals, and the use of invasive procedures such as endoscopy. (C) 2003 Wiley-Liss, Inc.