ABSTRACT
Similar to other vertebrates, the immune system of amphibians is divided into innate and adaptive, with innate immunity considered the first line of defense and adaptive immunity responding to specific antigens. Leukocytes in anurans are involved in both immune responses, being divided into lymphocytes, monocytes, neutrophils, eosinophils and basophils. These cells undergo changes during amphibian' development, with some of them more associated with the early stages of development (growth) and others with the final stages of metamorphosis. Leukocytes can also be affected by other stressors, such as environmental contaminants. Amphibians are especially susceptible to leukocyte alterations during their larval stages, as the immune defenses are not yet mature. In this chapter, we briefly contextualize the immune system in anuran amphibians and its development during metamorphosis, as well as some data on the effects of environmental stressors on tadpoles' leukocytes, cytokines and melanomacrophages.
