Estimation of hematological and biochemical parameters of a representative of the amphibious fauna of the Urals: Salamandrella keyserlingii (Caudata, Amphibia)

The paper has presented for the first time the results of a study of hematological and biochemical parameters of a threatened species of the fauna of the Middle Urals, Salamandrella keyserlingii (Caudata, Amphibia). Mature males of S. keyserlingii (n = 30; sampled in spring and summer) living in the Protected Area «Kalinovsky Forest Park» (Sverdlovsk Region, Russia), located in the urban agglomeration of Yekaterinburg city, were used as research objects. The leukocyte composition of S. keyserlingii blood is represented by granulocytes (neutrophils: early, bands, segments; basophils, eosinophils) and agranulocytes (monocytes and lymphocytes). The peripheral blood of individuals was characterised by the predominance of agranulocytes. They provide immune surveillance and selective reactivity of the organism (adaptive immunity) both in spring (55.7%) and summer (60.3%) seasons (p < 0.001). The content of granulocytes, providing non-specific urgent protection of the organism from infections and toxic effects, is ranged as 39.3–44.4% in males. In the spring and summer periods, the leukocyte formula of the peripheral blood of S. keyserlingii has a high lymphoid profile (52.4–56.7%). Seasonal variability of the integral leukocyte index (ISL) of S. keyserlingii was 0.80 in spring and 0.65 in summer. The content of free amino acids in the blood plasma of S. keyserlingii has been assessed for the first time from the standpoint of their participation in the processes of immunomodulation and the formation of adaptive reactions that ensures the survival and eurybiont of the species in a wide temperature range. The amino acid fund of S. keyserlingii blood plasma was represented by 17 amino acids: alanine, serine, threonine, lysine, leucine, valine, glycine, aspartic acid, glutamic acid, arginine, histidine, methionine, proline, phenylalanine, cystine, tyrosine, and isoleucine. The analysis of the metabolic groups of amino acids in the blood plasma of S. keyserlingii shows a high percentage of glycogenic amino acid (GGAA: 82.1%) and essential amino acids (EAA: 53.4%). The high content of amino acids in the blood indicates their relevance in the processes of protein synthesis, active participation in both immune processes and in the processes of detoxification and the formation of adaptive reactions during the summer period of amphibian’s growth and development. The obtained results of studies of hematological and biochemical parameters of S. keyserlingii’s blood significantly expand the understanding of the adaptation mechanisms of amphibians to conditions of natural and anthropogenic habitat transformations. This is undoubtedly of theoretical interest and applies significance for development of environmental measures in the monitoring system of natural and artificial aquatic ecosystems.