Hematology and Plasma Biochemistry Value Differences Between Acclimated and Recently Captive Female Southern Stingrays, Dasyatis americana

Abstract

Southern stingrays are used for interaction and education in captive and wild settings therefore it is important to monitor their health conditions.  Diagnostic tools that are useful for assessing health in other animals include hematology and plasma biochemistry profiles.  Certain reference intervals have been established in this species; however, interpretation of intervals in stingrays under different conditions are lacking.  The primary aim was to compare hematological and plasma biochemical values between seventeen female stingrays that were acclimated to captivity (n=8 adult) to those recently collected from the wild (n=9 immature).  Examinations included measuring disc width, ultrasound evaluation of the coelomic cavity, and blood collection.  The examinations were performed on both test groups at two time points: prior to introduction of the recently captive rays to the aquarium exhibit and eight months after cohabitation.  Hematology analysis included manual WBC counts, leukocyte differential, PCV, and plasma protein.  Plasma chemistry profiles included aspartate aminotransferase, bicarbonate, urea, calcium, creatine kinase, cholesterol, chloride, globulin, glucose, phosphorus, potassium, sodium, and total protein.  The two groups of stingrays’ results were compared using the Wilcoxon Rank Sum test.  The following parameters were found to have statistically significant differences (p<0.05) prior to introduction: bicarbonate, urea, calcium, cholesterol, chloride, globulin, potassium, total protein, and PCV.  The recently-captive rays had higher median values of urea, chloride, and potassium.  There were no significant differences after eight months of cohabitation.  Data interpretation for hematology and plasma chemistry values may be affected by the environmental changes for stingrays.