Analysis of elasmobranch coelomic fluid offers a novel diagnostic modality for the evaluation of elasmobranch health.1,4 The objectives of this study were to characterize coelomic fluid in clinically healthy and abnormal elasmobranchs. Fluid was collected via the coelomic pore in 91 individuals from 16 species spanning normal and abnormal animals. Comprehensive fluid analysis, osmolality, salinity, biochemistries, and in a subset of samples, bacterial and fungal cultures, protein electrophoresis, and lipoprotein electrophoresis, were performed. Common cytologic findings in both normal and abnormal animals included crystals suggestive of salt, mesothelial cells, and red blood cells. Abnormal animals had significantly higher coelomic phosphorus, salinity, cholesterol, calcium, specific gravity, and total protein compared to normal animals. Coelomic fluid from abnormal animals (n=37) contained white blood cells (n=15) and bacteria (n=7), suggestive of coelomitis. Leukocytes (rare lymphocytes and mononuclear phagocytes) were identified in only one normal animal. Bacteria were absent cytologically in normal animals. Aerobic bacteria were cultured from normal (n=7) and abnormal (n=11) animals, with bacterial isolation from normal animals presumably representing normal flora or sample contamination.2,3 Coccidia were absent in all samples. Yolk was identified in both normal and abnormal females. Protein and lipoprotein electrophoresis were not considered useful due to low concentrations of these analytes. Presence of a variable volume of coelomic fluid in elasmobranchs is a normal finding. Based on these results, coelomic fluid analysis demonstrated differences between normal and abnormal animals and offers an additional diagnostic tool in the clinical work-up of elasmobranchs.
The authors wish to thank Charlene Burns, Ryan De Voe, and Carolyn Cray for their assistance with this project. Very special thanks to the animal hospital and husbandry staff at the Seas with Nemo and Friends at Epcot and Castaway Cay, Bahamas, Disney’s Animals, Science and Environment, Bay Lake, FL, 32830, USA for their excellent care of these animals. This study was supported in part by the Bahamas Department of Marine Resources, the National Institute of General Medical Sciences (NIGMS) grant number P20GM104932, and COBRE, CORE-NPN, Chemistry Research Core.
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