Hematology, Morphology and Ultrastructure of Blood Cells and Blood Parasites from Puff-faced Watersnakes (Homalopsis buccata)

Abstract

Blood samples of 45 puff-faced watersnakes (Homalopsis buccata) in the Queen Saovabha Memorial Institute were collected from ventral caudal vein for both basic hematology and light microscopic, scanning and transmission electron microscopic features of blood cells. Seventeen samples (37.8%) were positive for hematozoa infections. The single infection of Hepatozoon sp., trypanosome and Haemogregarina sp. was found in 4, 4 and 5 snakes respectively. The other four snakes were infected by both trypanosome and Hepatozoon sp. There were no significant differences of all hematological value between the hematozoa-negative and the hematozoa-positive snakes except fibrinogen concentration which was found higher in the negative group. Lymphocytes were the most commonly observed leukocytes and average 6-8 μm in diameter. Azurophils were the second most commonly observed leukocytes, average 10-17 μm in diameter and might play a major role in eliminating the trypanosome. Heterophils were the largest leukocytes, average 16-19 μm in diameter and the third commonly observed leukocytes. Eosinophils usually were medium-sized cells, average 10-14 μm in diameter but in some occasion the very large cells were also detected. Basophils were smaller than heterophils and eosinophils. Scanning electron microscopy revealed the membrane surfaces of normal and abnormal erythrocytes, Hepatozoon sp. infected erythrocytes, thrombocytes, eosinophil and trypanosomes. Transmission electron microscopy revealed the organelles within azurophil, eosinophil, heterophil and trypanosome.