Leukocyte counts in blood smears of Antarctic seals and penguins: a new less time-consuming method

MENÉNDEZ-BLÁZQUEZ, JAVIER; SOTO, FLORENCIA; NEGRETE, JAVIER; COLOMINAS-CIURÓ, ROGER; MARÍN-SIERRA, ANDREA; RICCA, MELINA; BARBOSA, ANDRÉS

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2021 vol. 44 p. 2195 - 2198

0722-4060

Research on immune response in polar fauna is gaining great importance due to diferent scenarios of environmental change.Total leukocyte counts in blood smears are one of the most widespread practices and provide useful information about thehealth status of individuals. However, there is no methodological agreement for these analyses. Total leukocyte counts canbe performed at×400 magnifcation in optical microscopy using 10,000 erythrocytes for standardizing. However, countingsuch number of erythrocytes is costly and time-consuming. Here, we describe a new technique to simplify leukocyte counts inblood smears from Antarctic wildlife based on the number of microscope felds instead of the number of erythrocytes whichreduces considerably the time spent. We have counted total leukocytes using both methods in the three penguin species ofthe genus Pygoscelis?Adélie (P. adeliae), gentoo (P. papua), and chinstrap penguin (P. antarcticus)?and four Antarcticmammal species: crabeater seal (Lobodon carcinophaga), leopard seal (Hydrurga leptonyx), weddell seal (Leptonychotesweddellii), and southern elephant seal (Mirounga leonina) for validation. Our results show a high correlation between the totalleukocyte counts using 10,000 erythrocytes or 10 microscope felds for standardizing. These results show the reliability of thelatter method for counting the total number of leukocytes in diferent species of birds and mammals saving time and efort.