关键词: 齐口裂腹鱼, 胸腺, 组织学

Abstract: Morphostructure and histostructure of the thymus of Schizothorax prenat(Tchang) were studied by anatomic and histological techniques. The results are as follow:The thymus is situated on either side of the upper corner of the opercular cavity and the fourth gill-bow. It lies closely under the membrance of the opercular cavity. The parenchyma of the thymus is not obviously divided into the lobules. The thymus consists of the outer, middle, and inner regions. But there is no obvious demarcation between the middle and inner regions. The cells of the middle region are in large number and it is stained intensely. The cells of the inner region are distribnted loosely. Two regions consist chiefly of lymphocytes and reticuloepithelial cells, whose structural features are similar to those of the cortex and medullary region of the higher vertebrates respectively. In addition, there are a few plasma cells and mast cells in the thymus.

Key words: SCHIZOTHORAX PRENAT(TCHANG), THYMUS, HISTOLOGY