Abstract

Many elasmobranch species are kept for display or conservation purposes by zoos and aquaria where appropriate veterinary care and health monitoring require routine handling to obtain blood and tissue samples. However, normal shark physiological parameters are not well-documented and changes associated with captivity have not been investigated in great depth. The effects of potentially stressful events such as handling and transport remain poorly understood. It was our objective to examine changes in plasma biochemistry that may 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. In addition, we addressed the difference in those changes between 5 sharks maintained in natural seawater at a salinity of 30.5 ppt and 5 animals in artificial seawater with a salinity of 35.0 ppt.

Plasma levels of chloride, calcium, phosphorous, cholesterol and triglycerides were significantly (p<O.05) higher in the sharks maintained in water at the higher salinity artificial seawater prior to simulated transport. During simulated transport, significant differences in plasma sodium, potassium, chloride, calcium, phosphorus, blood urea nitrogen, aspartate aminotransferase, gamma glutamyltransferase, cholesterol and triglyceride were evident between the two groups of sharks. In the animals kept at the higher salinity artificial seawater, plasma calcium, magnesium, phosphorous and alkaline phosphatase increased significantly during the simulated transport, while plasma potassium decreased. No significant variation occurred in animals kept at the lower salinity natural seawater.

The current report identifies changes that occur in plasma biochemical constituents associated with transport and handling in the sand tiger shark and underlines the effect of environmental factors upon those parameters.