Biochemical and hematological profile of Otaria flavescens in the reproductive colony of Cobquecura, central-south Chile

Abstract

Despite the ecological importance of the common sea lion Otaria flavescens, there is currently no information available on the blood chemistry and hematology of this species. Here, we report for the first time, 14 blood chemistry variables of O.flavescens and differential blood cell counts obtained from 15 resident individuals from a reproductive colony located in Cobquecura on the coast of central-south Chile, during 2 sampling periods, in 2009 and 2011. There was a high degree of biochemical regularity in studied parameters, although the plasmatic concentration of calcium differed significantly between genders; average concentrations of total proteins, globulins, cholesterol, and cholinesterase activity varied significantly between sampling periods. In comparison with the biochemical profiles reported for other marine mammals, O.flavescens had greater concentrations of globulins; an inhibitory capacity of antiproteases (close to 100%); and moderate to low cholinesterase activity and similar concentrations of glucose. Finally, differential blood cells counts indicated moderate to high eosinophilia (8.3-17.6%) in individuals sampled during the first sampling period, which suggests the possible presence of parasitism within this population. These results could be useful for assessing the state of health of O. flavescens populations and, therefore, contribute to species conservation in the Southeast Pacific.