Morphological and Cytochemical Studies of Peripheral Blood Cells of Schizothorax prenanti

Abstract

The morphological and cytochemical studies of peripheral blood cells of Schizothorax prenanti were studied by light and electron microscopy. Erythrocytes, thrombocytes and three types of leucocytes, lymphocytes, neutrophils and monocytes, were distinguished and characterized. In addition to mature erythrocytes, immature and dividing erythrocytes were observed. A few organelles such as mitochondria were distributed in the cytoplasm of erythrocytes. Lymphocytes with heavily clumped heterochromatic nucleus and minimal cytoplasm were classified into small and large lymphocytes. Three different populations of granules, with distinctive ultrastructural aspect, were observed in neutrophils. Monocytes were the fewest leucocytes possessing rich organelles, phagocytized materials and vacuoles. Thrombocytes with various types were the most abundant blood cells among leucocytes and contained a prominent nucleus with dense bands of heterochromatin and many cytoplasmic vacuoles. Periodic acid-Schiff staining was positive in neutrophils, monocytes, lymphocytes and thrombocytes, but not in erythrocytes. Peroxidase-positive staining was observed in neutrophils and monocytes, but not in erythrocytes, lymphocytes and thrombocytes. Only neutrophils were positive for oil red O. Except for erythrocytes, the other blood cells stained positively for acid phosphatase. Only neutrophils and monocytes were positive for α-naphthyl acetate esterase. None of the cells studied were positive for alkaline phosphatase. The morphologic and cytochemical features of blood cells of S. prenanti are similar to those of other fish. This investigation may be helpful as a tool to monitor the health status of cultured S. prenanti and will grant early detection of clinical pathology.

Ultrastructural and Cytochemical Properties of Peripheral Blood Cells of Piebald Naked Carp (Gymnocypris eckloni)

“…They differ in number, type and structure, but there is no uniform standard for the classification of granules in neutrophils (Gao et al, 2007). In this study, G. eckloni neutrophils exhibited only a single population of granules, which is quite different from those of S. prenanti in which neutrophils presented three types of granules (Fang et al, 2014). Moreover, the granules in G. eckloni neutrophils contained an eccentric, spherical or oval electron-dense core.…”

“…In G. eckloni blood, the predominant erythrocytes were matured erythrocytes, whose ultrastructure features were similar to those of Schizothorax prenanti (Fang et al, 2014) and other fish species (Gao et al, 2007;Zhang et al, 2011;Motlagh et al, 2012). Like most fish, there were a few mitochondria in the cytoplasm of mature erythrocytes in G. eckloni.…”

“…Moreover, the granules in G. eckloni neutrophils contained an eccentric, spherical or oval electron-dense core. This is also dissimilar to Pleuronectes platessa (Ferguson, 1976), Ictalurus punctatus (Cannon et al, 1980), Morone saxatilis (Bodammer, 1986) and S. prenanti (Fang et al, 2014). In these fish, the neutrophils granules contained dense, bar-shaped crystalloids in centre.…”

“…The staining procedures for PAS, NAE, PER, ACP and ALP were carried out according to the method described by Fang et al (2014). For SBB staining, the blood smears were fixed with methanol and calcium solution (1 g calcium chloride and 10 ml methanol in 90 ml double distilled water) for 3 min.…”

“…Thus, analysis of specific ultrastructural characteristics of blood cells, including enzyme, glycogen and fat components, is essential to confirm the identity and likely function of different cell populations (Hine et al, 1990;Shigdar et al, 2009). The need to identify these features in blood cells encouraged numerous studies on teleosts (Zhiteneva et al, 1989;Zinkl et al, 1991;Burrows et al, 2001;Tripathi et al, 2004;Tavares-Dias, 2006;Gao et al, 2007;Pavlidis et al, 2007;Tavares-Dias et al, 2007a,b;V azquez and Guerrero,2007;Prasad and Charles, 2009;Santos et al, 2009;Shigdar et al, 2009;Zhang et al, 2011;Motlagh et al, 2012;Fang et al, 2014). However, the functional and phylogenetic significance of fish blood cells remains unresolved, and there is a need for comparative studies.…”