INFLUENCE OF SEASON, ENVIRONMENT, AND SEX ON SELECTED BLOOD PARAMETERS OF GEOFFROY'S SIDE-NECKED TURTLES, PHRYNOPS GEOFFROANUS (SCHWEIGGER, 1812).

Abstract

Laboratory tests help to determine a diagnosis, to plan treatment, and to indicate prognosis of diseases. However, the interpretation of test results in reptiles is challenging, because they are influenced by environmental and individual factors. Therefore, the objective of this study was to establish hematologic parameters of Geoffroy's side-necked turtle (Phrynops geoffroanus), including variables such as season, environment, sex, and straight carapace length (SCL). Blood samples were analyzed from 38 P. geoffroanus (23 males and 15 females) collected during the rainy and dry seasons. Some of the animals were from captivity and others from an urban stream. To verify the influence of the variables on blood parameters, the general linear model was performed. The Pearson correlation coefficient was also used to verify the association between SCL and hematologic parameters. Among these parameters, hemoglobin (P = 0.008) and mean corpuscular hemoglobin concentration (P = 0.001) were statistically higher during the rainy season. On the other hand, WBC (P = 0.011), heterophils (P = 0.045), eosinophils (P < 0.001), lymphocytes (P = 0.014), and monocytes (P = 0.039) were higher in the dry season. The RBC count (P = 0.035), PCV (P = 0.029), basophils (P = 0.013), and monocytes (P = 0,013) were significantly higher in individuals from captivity, but lymphocytes (P = 0.033) were higher in the urban turtles. Only eosinophils (P = 0.025) were higher in females than in males. There was no influence of the variables season, environment, and sex on the mean corpuscular volume (P = 0.071; P = 0.458; P = 0.052), total solids (P = 0.773; P = 0.121; P = 0.131), and heterophil:lymphocyte ratio (P = 0.992; P = 0.58; P = 0.119). No influence of the size on hematologic parameters was observed. Season, environment, and sex may influence the blood parameters of P. geoffroanus, and these factors should be routinely considered in the interpretation of laboratory results.