放流前大麻哈鱼幼鱼头肾和脾脏的组织学观察

Histological observation of head kidney and spleen of juvenile Oncorhynchus keta before release

通过了解大麻哈鱼(Oncorhynchus keta)免疫器官的特点,探索大麻哈鱼放流苗种培育过程中鱼体免疫应答机理,采用解剖学和常规组织学方法对放流前大麻哈鱼幼鱼的头肾、脾脏进行了组织学观察。结果表明,头肾位于食道背面、胸腔内咽退缩肌上方,表层覆盖一层致密的结缔组织被膜;头肾实质含有退化的肾小管处于泌尿与免疫混合功能期,实质内部充满淋巴细胞、中性粒细胞、血细胞和黑色素巨噬细胞,具有明显的黑色素巨噬细胞中心。脾脏位于胃组织下方,肠道中部背面,表面光滑呈红褐色;外层有被膜包裹,实质由排列模糊的红髓和白髓组成,中央静脉和动脉血管丰富,红髓内分布着由大量血细胞聚集形成的血窦,而白髓由大量淋巴细胞、中性粒细胞填充;黑色素巨噬细胞在脾脏实质内散乱分布且黑色素巨噬细胞中心明显。放流前大麻哈鱼幼鱼头肾和脾脏具有较强的造血功能和免疫功能。

By understanding the characteristics of the immune organs of chum salmon,it provided a research basis for exploring the immune response mechanism of the released juvenile chum salmon during the breeding process.The anatomy and conventional histo⁃logical techniques were used to observe and study the head kidney and spleen of juvenile chum salmon before release.The results showed that the head kidney was located on the back of the esophagus,above the pharyngeal retractor muscle in the thoracic cavity,and the surface was covered with a dense connective tissue capsule.The head kidney contained vestigial renal tubules,and it was in the mixed urinary and immune function stage,and the head kidney was full of lymphocytes,granulocytes,blood cells and melaninmacrophages,with a distinct melanin-macrophage center.The spleen was located below the stomach tissue,the back of the middle in⁃testine,and the surface was smooth and reddish brown.The spleen outer layer was wrapped by a membrane,and the substance was composed of vaguely arranged red pulp and white pulp.The central venous and arterial blood vessels in the spleen were abundant.The red pulp contained sinusoids formed by a large number of blood cells,while the white pulp was filled with a large number of lympho⁃cytes and granulocytes.The melanin macrophages were scattered in the spleenand the melanin macrophages center was obvious.The head kidney and spleen of the juvenile chum salmon had the strong hematopoietic and immune functions before release.