Morphology, cytochemistry and ultra-structure of blood cells in large Indian civet Viverra zibetha (Carnivora, Viverridae)

Viverra zibetha, also known as the large Indian civet, is found from Indochina to southern China. This species is listed as Near Threatened. Blood samples from four adult (two males and two females) large Indian civets in Khao Kheow Open Zoo, Thailand, were prepared for morphological, cytochemical and ultra-structural observation. The red blood cells showed marked anisocytosis, with a mean diameter of 5.0 µm. The cytochemical staining (Sudan black B, peroxidase, α-naphthyl acetate esterase and β-glucuronidase) patterns of leukocytes and haematology were summarised. Eosinophils contained numerous short rod, red refractive granules. Eosinophils lacked sudanophilia and peroxidase activity. Under scanning electron microscopy (SEM), eosinophils showed rod-shaped granular surfaces. Ultra-structurally, these granules contained lamellar components. Basophils had dull grey, round to oval granules. Under SEM, the basophil surface was smooth with pleomorphic granular contours. Ultra-structurally, the basophil granules contained crystalloid components. Neutrophil engulfed red blood cells, and a sac of eosinophil granules was observed under a transmission electron microscope. These results provide more information on morphological, cytochemical and ultra-structural characteristics of blood cells in large Indian civets.