Plasma biochemical changes in response to transport, handling, and variation of water quality in sand tiger sharks
Elasmobranch species kept for display or conservation purposes often need to be handled to obtain blood and tissue samples for health monitoring. However, normal physiological parameters for sharks are not well-documented and changes associated with captivity and changing environmental conditions or potentially stressful events such as handling and transport remain poorly understood. The current study examined changes in plasma biochemical parameters that occur in response to simulated transport by taking blood at regular intervals from sand tiger sharks ('Odontaspis taurus') maintained in transport containers for up to 8 hours. This thesis also identifies differences in selected plasma biochemical constituents in sharks transferred to a natural sea water holding facility (salinity 30.5 ppt) after being maintained in artificial sea water with a salinity of 35 ppt. Finally, the difference in the changes occurring during simulated transport between sharks maintained in natural and artificial sea water are reported. Significant increases in plasma chloride, calcium, magnesium, phosphorus, and glucose and a significant decrease in plasma potassium were found during simulated transport of sharks maintained in artificial sea water. Sharks maintained in higher salinity artificial sea water had significantly higher plasma sodium, chloride, calcium, phosphorus, and blood urea nitrogen levels. Simulated transport of animals in the lower salinity natural sea water caused a significant decrease in only magnesium levels. The other measured parameters were not affected. The finding that some plasma constituents did not change under the same transport conditions in animals maintained in differing environments highlights the complexity of adaptation to changing water conditions in sand tiger sharks. This report identifies the need to take into account changes in environmental conditions prior to establishing criteria of health in sand tiger sharks.