Morphological and Cytochemical Characteristics of Leukocytes in Sevenband Grouper Epinephelus septemfasciatus

Abstract

Morphological characteristics of leukocytes from sevenband grouper Epinephelus septemfasciatus (MA-HA-TA in Japanese) peripheral blood were examined using multiple Romanowsky-type stain valuation. Lymphocyte, monocyte, neutrophil and two types of eosinophil were observed in the blood of the grouper. Lymphocyte had a round to oval nucleus with coarse chromatin-mesh. Cytoplasm contained some basophilic granule (lymphocyte basophilic granule, LBG). Monocyte had round to lobule-shaped nucleus with fine chromatin-mesh. Two types of granules, monocyte major granule (MMG) and monocyte minor granule (MmG) were observed in the cytoplasm. The latter granule was stained reddish purple with May-Grünwald (MG) and MG-Giemsa (MGG) or colorless with Giemsa. Neutrophil were polymorphonuclear and contained round to oval chromophobic granule (βG) and Yasumoto body. Eosinophil had round to oval nucleus, eosinophilic granule and classified into two categories, type 1 and type 2. The former had round granule, the latter had rod-shaped granule. Cytochemical characteristics of the leukocytes were also examined.