Morphology of Blood Cells, Liver and Spleen of the Desert Tortoise (Testudo graeca)

The morphological characteristics of peripheral blood cells, the anatomical structure of the liver and spleen were examined in desert tortoise. Forty healthy adult Testudo graeca tortoises, 20 females and 20 males were selected for this study. The tortoises were given thorough examination, and a blood sample was collected from the heart by cardiocentesis. The Wright staining method was used for classification of the blood cells. Seven different types of blood cells were determined: erythrocytes, heterophils, eosinophils, basophils, lymphocytes, monocytes and thrombocytes. Mature erythrocytes of captive Testudo graeca were nucleated ellipsoidal cells. Erythrocytes measurements for males were (length 18.76 ± 2.81 m width 9.52 ± 2.23 m) and for females were (length 19.19 ± 2.90 m width 9.84 ± 2.50 m). The heterophil contain large, eosinophilic, ovoid, cytoplasmic granules with eccentric nucleus. The eosinophil is distinguished by its round, eosinophilic cytoplasmic granules and the nucleus is round to oval, single or bi-lobed, and eccentrically placed within the cytoplasm. The basophil was easily identified by its deeply stained purple, large, round granules that remained tightly adhered to the centrally located nucleus. The lymphocyte contained a small amount of blue staining cytoplasm and a round nucleus with a fine reticular pattern. The monocyte contains a large amount of light bluegray, finely granular or vacuolated cytoplasm, and an oval or indented nucleus. Thrombocytes were oval-shaped cells contained round, densely stained nucleus. The liver composed of two lobes, right and left which were connected with a narrow band of connective tissue. The parenchyma of the tortoise liver is seen to be composed of intersinusoidal cords of hepatocytes. The spleen grossly appeared as round or oval structure. The parenchyma (splenic pulp) formed of lymphoid tissue and is of two distinct types; white and red pulps. Overall, this study provides identification of the morphological characteristics of different peripheral blood cells of the tortoise Testudo graeca species as well as the anatomy of the liver and spleen, as a reference for future hematological studies of this species and may be used as a basis for comparison in clinical cases.