Successful hand-rearing of ocellated eagle rays (Aetobatus ocellatus)
Citation
Williams SM, Mylniczenko ND, Murphy D, Vaughn A, Davis L, Sullivan KE, Hesse T, and Bissell H. 2025. Successful hand-rearing of ocellated eagle rays (Aetobatus ocellatus). In Treiber K, Brooks M, D’amato-Anderson J, Nylander J, Eds. Proceedings of the Sixteenth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Oklahoma City, OK.
Abstract
Ocellated eagle rays (Aetobatus ocellatus) give birth to live pups without providing parental care. Even without the presence of a male, these rays have been shown to reproduce through parthenogenesis (Harmon et al. 2015). Therefore, institutions should be prepared for pregnancy, even in their single sex female populations. Pups can take days to weeks to master foraging and to consistently consume adequate calories to support proper growth and development. While pups learn these skills, many times, nutritional and veterinary support are essential to ensure the pup has the energy required to maintain body condition and strength. Nutritional supportive care (enteral and parental) may be crucial for meeting the caloric needs of these neonatal elasmobranchs (Williams et al. 2024). While body condition scoring of newborn animals using published methods in adults (Kamerman et al. 2017) can be a fair indication of fitness at birth, full physical examination within the first weeks is recommended to evaluate true liver and muscle condition. Monitoring fecal quality is important for ensuring pup health and digestion. Pre-birth procurement of preferred early foods is essential to start the process. Offering live bivalves and mollusks, including coquina (Donax trunculus), sunray venus (Macrocallista nimbosa), and hard-shell clams (Mercenaria mercenaria), and periwinkle snails (Littorina littorea) are the most enticing options to newborn eagle ray pups to stimulate consumption. Successfully hand-rearing newborn pups of this species may seem challenging, but a coordinated multidisciplinary approach to husbandry, health, and nutrition is key to success.
WilliamsRayZN2025HRLightning.pdf 148 KB
