COMPARISON OF PRE- AND POSTQUARANTINE BLOOD CHEMISTRY AND HEMATOLOGY VALUES FROM WILD-CAUGHT COWNOSE RAYS (RHINOPTERA BONASUS)

Abstract

Though one of the most widely kept elasmobranchs in human care, the cownose ray (CNR; Rhinoptera bonasus ), remains a species with minimal published information on hematologic reference intervals. As part of a larger study investigating the health and nutrition of the CNR, this study established a preliminary data set of plasma chemistry and hematology values specific to animals recently caught from the wild and compared this data set (intake sample) to values obtained following a period of quarantine (27-40 days) in an aquarium (exit sample). Blood samples were collected from 47 wild female (n = 46) and male (n = 1) CNR caught in pound nets off the coast of North Carolina and South Carolina. Differences between intake and exit values were analyzed. Due to the preponderance of female animals, data were not analyzed for sex differences. Plasma biochemical profiles were performed and analyzed. A select number of complete blood cell counts were performed (n = 24 from 12 animals). Statistically significant differences (P < 0.05) specific to time of sampling were determined for packed cell volume, total solids, blood urea nitrogen, sodium, chloride, potassium, phosphorus, cholesterol, glucose, and aspartate aminotransferase. Values reported are a significant expansion on the existing limited data for CNRs and will serve as a reference for health assessment of individuals both in the wild and in exhibit populations.

Hematology and Plasma Chemistry Reference Values in Nursehound Shark (Scyliorhinus Stellaris) Maintained Under Human Care

“…Former hematological studies with elasmobranchs also showed important variations in leucocyte differential counts between the different elasmobranch species ( 10 , 15 ). Lymphocytes, monocytes, FEG, and CEG appear to be present in all the studied elasmobranch species, though their proportions in the leukocyte differential counts vary greatly across shark and ray species ( 13 , 36 , 37 ). In our study, median proportion of the major leukocyte types was similar to other Carcharhinid sharks, with lymphocytes as the predominant WBC with 38.0% of all leukocytes, followed by CEG with 20.0%, FEG with 6.0%, monocytes with 2.0%, and neutrophils with 2.0%.…”

“…Nursehound Shark had similar plasma triglyceride (median 0.97 mmol/l) and total cholesterol (2.05 mmol/l) levels compared to those previously reported in their close relative the Small-spotted Catshark (1.27 mmol/l and 2.85 mmol/l, respectively) and in other elasmobranchs under human care such as the Spotted Eagle Ray (0.89 mmol/l and 2.56 mmol/l, respectively) and were higher than those reported in free-ranging Grey Nurse Shark (0.30 mmol/l and 1.40 mmol/l, respectively) ( 12 , 14 , 31 , 34 , 58 ). The lowest triglyceride and cholesterol values observed in free-ranging elasmobranchs compared to those under human care could indicate a lower energy deficit in animals maintained un aquaria, which are regularly fed, suggesting that triglyceride levels could turn into a useful indicator for health assessments ( 14 , 36 , 59 ).…”

“…), and the Port Jackson Shark (Heterodontus portusjacksoni) (24,38,39). However, GT seem to be absent in other Non-Carcharhinid elasmobranch species such as the aquarium-maintained Cownose Ray and the aquarium-maintained Whale Shark (Rhincodon typus), where FEG have been reported as the most frequent peripheral granulocyte (36,37). Granulated thrombocytes do not have a clear mammalian equivalent cell and their specific role in elasmobranchs remains unknown (30,35).…”

Serum Protein Analysis of Nurse Sharks

“…Elasmobranch serum EPH fraction concentration RIs have yet to be widely determined, as this taxonomic group is underrepresented in clinical literature (Harms et al 2002;Cain et al 2004;Ferreira et al 2010;Haman et al 2012;Persky et al 2012;Krol et al 2014;Cray et al 2015;Cusack et al 2016;Hyatt et al 2016). To establish RIs, blood must be collected from 120 individuals within a species as recommended by the American Society for Veterinary Clinical Pathology.…”

Pharmacokinetic Studies in Elasmobranchs: Meloxicam Administered at 0.5 mg/kg Using Intravenous, Intramuscular, and Oral Routes to Nursehound Sharks (Scyliorhinus stellaris)

“…While handling can be challenging and dangerous in larger elasmobranchs, smaller species may not allow for sufficient collection of blood volumes required to develop a PK study, seeing as the recommended total blood collected from fish should be <1% of its body weight in a 2-week period ( 24 ). The small cell fraction present in elasmobranch peripheral blood (mean PCV ranging from 15 to 30%) permits the obtainment of high plasma volumes, reducing the blood volume required to develop the PK analysis ( 25 , 26 ). The total 5.6 ml, 3.6 ml, and 4.9 ml blood collected over 48 h in the studies performed with IV, IM, PO administration, respectively, represent 0.21, 0.13, and 0.18% of the mean body weight (2.69 kg ± 0.43 kg) of the nursehounds sampled in this study.…”