Temperature, stress and the distribution of leukocytes in red-spotted newts,Notophthalmus viridescens

Summary

Adult newts,Notophthalmus viridescens, were maintained in constant darkness and at a constant temperature of 3.5 °C or of 11.0 °C or of 21.0 °C. Animals of each group were sacrificed after an 8-day sojourn in their constant environments, at which time blood smears for each newt were prepared. Differential counts of leukocytes of the animals maintained at 3.5 °C and of those that lived at 21.0 °C were compared with the differential counts of the newts that lived at 11.0 °C. In the blood of animals maintained at 3.5 °C and at 21.0 °C, there were more neutrophils and fewer lymphocytes than the same types of cells in the blood of newts that lived at the intermediate temperature, 11.0 °C (Table 1). Those differences, statistically significant atP<0.001, may indicate that the constant high and low temperatures constitute physiological stress for this species.