Abstract
Elasmobranchs are a unique and enigmatic group of animals in which clinical disease can be masked. Biochemical profiles, including protein electrophoresis (pEPH), have been shown to be useful tools for identification and monitoring of disease.1 Baseline reference intervals are often lacking in elasmobranch species, and there is even less information regarding changes in these parameters during disease processes. In humans there are changes in lipoproteins during the acute inflammatory process, which can be measured by cholesterol electrophoresis (cEPH).2,3 Previous studies in elasmobranchs found different proportions of lipoprotein types than typically seen in mammals, associated with lack of albumin as a free fatty acid transport protein.4,5 A recent study evaluating pEPH and cEPH in cownose rays identified significant elevations in total solids and cholesterol levels, the latter related to increased very low density lipoprotein levels (VLDL), in rays with an abnormal health status.5 The current study is the first to evaluate pEPH (n=84) and cEPH (n=68) in the spotted eagle ray (Aetobatus narinari). Animals were divided into three subgroups for comparative analysis of the pEPH: clinically normal (n=34), clinically abnormal (n=30), and free ranging animals handled for health assessment surveys (n=20). Similar to the previous study in cownose rays, in cEPH profiles fractions 3 and 4 were dominant, corresponding to VLDL and low density lipoproteins (LDL) by mammalian fraction delimits. pEPH fractions 1 and 4, corresponding to albumin and beta globulins by mammalian fraction delimits, were dominant for all animals. This contrasts the previous study in cownose rays where fraction 1 was not dominant. Fraction 1 was significantly higher in healthy aquarium maintained compared to free ranging rays (p=0.0002 whereas fraction 4 was significantly higher in free ranging rays (p<0.0001). The ratio (mean±SE) of fraction 1 to 4 was 0.60±0.04 in aquarium maintained rays vs. 0.27±0.01 in free ranging rays (p<0.0001). A decreased total protein was observed in clinically abnormal animals (p=0.05). Significantly lower fractions 1 and 5 were also observed (p≤0.04). Some animals with parasitism, wounds, and trauma exhibited marked increases in fraction 4 while others had elevated fraction 1. The ratio of fraction 1 to 4 varied from 0.23–0.99. In total, these data indicate that electrophoretic profiles may be a useful disease identification and monitoring tool in the spotted eagle ray.
* Presenting author
+ Student presenter
Acknowledgements
The authors wish to thank Mote Marine Laboratory staff for assistance in collecting free ranging animal data and Georgia Aquarium veterinary and zoological operations staff for assistance in collecting aquarium-maintained animal samples.
Literature Cited
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