HEMATOLOGY, SERUM CHEMISTRY, AND MORPHOMETRIC REFERENCE VALUES FOR ANTILLEAN MANATEES (TRICHECHUS-MANATUS-MANATUS)

Morphometric, hematologic, and serum chemistry reference values were determined for 12 clinically normal male and female Antillean manatees (Trichechus manatus manatus) captured from a zoological park in Guyana. The goals of this study were to establish reference values for this endangered species and to compare the results with published values for the Florida manatee (Trichechus manatus latirostris). Average total body length and fluke length of male and female Antillean manatees were smaller than those of the Florida manatee. In addition, visual comparison of the two subspecies revealed differences in intraocular eye distance, orbital placement, and snout size. The majority of hematologic and serum chemistry measurements in this study were similar to those reported for the Florida manatee. Microscopic assessment of blood films revealed that Antillean manatees had neutrophils rather than heterophils that have been observed in Florida manatees. Barr bodies were identified in neutrophils of all adult female Antillean manatees. In addition, some neutrophils had hypersegmented nuclei (more than five lobes), and most eosinophils had hyposegmented nuclei with cytoplasmic granules that were small, round, and bright pink. Wide variation in creatine kinase values was attributed to blood collection technique and the muscle exertion that occurred during capture. Serum values for total CO2 (TCO2) were lower and those for calculated anion gap were higher than reported values for Florida manatees and other mammals. The reduction in TCO2 concentration was indicative of metabolic acidosis. Two mechanisms for the acidosis are suggested. The increase in anion gap demonstrated an accumulation of organic acids in the blood. Lactic acidemia from muscle exertion was suspected. Acidosis could also have been a compensatory response to a respiratory alkalosis caused by hyperventilation and heat stress. Laboratory and morphometric data from a juvenile female Antillean manatee are reported.