Morphological Observations on the Erythrocytes, Leukocytes and Thrombocytes of Blue Tongue Lizards (Lacertilia: Scincidae, Tiliqua)

Blood cell appearances and sizes varied little between T. scincoides and T. rugosa. Both mature and immature erythrocytes were present in circulating blood. They were oval and, ultrastructurally, had prominent marginal microtubules. Thrombocytes were oval and often showed vacuolation. On TEM examination they had parallel arrays of microtubules and scattered dense granules. Lymphocytes were small and sometimes difficult to distinguish from thrombocytes. Ultrastructurally, they had few organelles in their cytoplasm. Monocytes were commonly packed with fine azurophilic granules which, ultrastructurally, corresponded to variably-shaped dense granules. Type I granulocytes had eccentric, irregularly shaped nuclei, and cytoplasm which contained many orange-brown oval to round granules. Ultrastructurally, the granules were membrane bound, dense, and round to elongate oval. Type II granulocytes had eccentric, oval to round nuclei and numerous purple red, round to irregularly oval granules. On TEM examination the granules were commonly large, light grey and reticulate, and often contained a variably sized fibrillar rod. Type III granulocytes had a centrally located nucleus and numerous round, purple blue granules. The granules were round and homogeneously dense at the ultrastructural level.