Monitoring Blood Parameters for a Captive Population of Nurse Sharks (Ginglymostoma cirratum)

Rachel T. Ransom

Introduction
Blood is extremely useful as both a diagnostic and research tool that can provide information about an animal’s health and physiological condition. Routine blood collection and observation is an important way to monitor the health of captive nurse sharks over time when compared to the literature and to other captive facilities such as SeaWorld Adventure Parks of Orlando. 

Methods
The monitoring of electrolytes and blood minerals requires the drawing of blood by caudal venipuncture. Blood is then processed by standard hematological techniques and used for automated blood chemistries and to make blood smears for cell counts. 

The smears are fixed in methanol and stained with Wright-Giemsa stain to be observed under a microscope. 

Blood samples have also been sent to Regional Biomedical Laboratories for electrolyte panels and comparisons for quality assurance. The lab provides blood cell differentials and quantitative chemistries for electrolytes, urea nitrogen, cholesterol, total protein, calcium, and other trace elements.

Results
The blood chemistries of the Albion animals match favorably with those of SeaWorld.  The Albion chemistries for each experimental animal are consistent with one another which suggests that all animals are responding physiologically in similar ways to the captive environment.

The differentials for Albion sharks are not consistent with the literature (Walsh et al.) Granulocyte numbers are higher for the animals on campus while lymphocyte numbers are lower.

Discussion
High levels of granulocytes are often indicators of infection or distress.  No signs of either of these have been found in the Albion lab.  It is suspected that the increased presence of granulocytes may be due to stress caused by transportation and a new environment.  If this is the case it is suspected that these numbers will  become more favorably comparable with previously published values over time as the animals acclimate to the Albion captive facilities. Continued surveillance of animal health will be done for the captive nurse sharks on campus.

Literature Cited
Walsh, CJ and Luer, CA. 2004. Elasmobranch Hematology: Identification of Cell Types and Practical Applications. In M. Smith, D. Warmolts, D. Thoney, R. Hueter. Elasmobranch Husbandry Manual: Captive Care of Sharks, Rays, and their Relatives. Ohio Biological Survey Inc. Pp. 307-323.

Acknowledgements
I would like to thank Dr. Jeffrey Carrier, Briton Shark Lab, SeaWorld Adventure Parks of Orlando, FURSCA, and the Albion College Biology Department for their help.