Reptiles are the unique ectothermic amniotes, providing the key link between ectothermic anamniotes fish and
amphibians, and endothermic
birds and
mammals; becoming an important group to study with the aim of providing significant
knowledge into the evolutionary
history of
vertebrate immunity.
Classification systems for
reptiles'
leukocytes have been described by their appearance rather than function, being still inconsistent. With the advent of modern
techniques and the establishment of analytical
protocols for
snakes'
blood by
flow cytometry, we bring a qualitative and quantitative assessment of innate activities presented by
snakes’ peripheral
blood leukocytes, thereby linking flow cytometric features with fluorescent and
light microscopy images. Moreover, since
corticosterone is an important
immunomodulator in
reptiles,
hormone levels of all
blood samples were measured. We provide novel and additional information which should contribute to better
understanding of the development of the
immune system of
reptiles and
vertebrates.