Abstract

The cownose ray (Rhinoptera bonasus) is an elasmobranch species often exhibited in aquaria, and for which the understanding of environmental health factors is still developing. Water quality is carefully maintained in aquaria and as a result, these habitats may have vastly different microbial communities than natural environments. This study aimed to evaluate the effect of environmental microbial diversity on animal health in an aquarium-maintained population of cownose rays by comparing microbial communities in an off-exhibit control system and a seasonal outdoor interactive touch pool system containing these animals. We hypothesized that there would be a more diverse microbial community in the touch pool and that animals inhabiting the touch pool would have detectable differences in some health assessment parameters when compared to control animals. Fifty-eight animals were divided into two groups: 18 control animals and 40 animals in the outdoor touch pool system over a period of 6 months. Baseline and follow-up environmental and animal microbial data, as well as physiological health parameters were collected during the study period. Significant differences in albumin/globulin ratio, heart rate, and lactate were found between control and touch pool populations, and significant differences in weight, total solids, heart rate, pH, and lactate were found in the touch pool population between their baseline and follow-up measurements. The clinical significance of these findings is discussed relative to descriptions of the microbial community ecology in each system and in the animals themselves.

Acknowledgements

We thank the staff of the Animal Health and Fishes Departments at the John G. Shedd Aquarium for their care of the study animals and assistance in data collection. We also thank Dr. Carolyn Cray and the University of Miami Avian and Wildlife Laboratory for assistance performing plasma electrophoresis.

* Presenting author