Detection of Serpentoplasma sp. (Apicomplexa: Haemohormidiidae) in dice snake (Natrix tesellata) (Colubridae: Natrix) in Azerbaijan.

The aim of this study was to determine the presence of blood parasites in dice snake (Natrix tesellata) from Pirallahi Island, located off the western coast of the Caspian Sea of Azerbaijan. The dice snake is one of the most widespread and common species of the herpetofauna of Azerbaijan. This species of snakes represents an important link in the natural balance, since included in various biocenotic connections. A total of 67 specimens of dice snake individuals were captured during spring and summer 2021-2024. Blood sampling was carried out from the caudal vein by insulin syringe. The blood smears were stained with Giemsa solution and examined by light microscopy for haemoparasites. Microscopical examination of the blood smears revealed that 23 snakes of 67 (15.4%) were infected with Serpentoplasma sp. Multiply infected erythrocytes with one to three parasites were unusual, with most host cells containing a single inclusion. Infected thrombocytes were not detected. The parasites contained round-to-oval inclusions from small, anaplasmoid-like bodies, vacuoles with a dot or two of apparent chromatin on their margin or without chromatin dots. The structures were intracytoplasmic, measured 3-3.8 Å~ 2.5-3.3 μm and occurred as rounded vacuole-like structures, one in each infected erythrocyte. This is the first finding of haemoparasites in dice snakes in Azerbaijan.