该文采用光学显微镜和透射电镜技术观察不同盐度下(5、20、30)人工选育卵形鲳鲹(Trachinotus ovatus)鳃线粒体丰富细胞的分布和超微结构变化。结果表明, 线粒体丰富细胞主要分布于鳃丝和鳃小片基部, 且随盐度升高而体积增大, 数量增多;三个盐度组均存在由线粒体丰富细胞、扁平细胞和附细胞构成的顶端小窝, 盐度5组线粒体丰富细胞顶膜面积较大, 微脊发达, 顶端小窝内凹, 盐度20和30组线粒体丰富细胞顶膜面积相对较小, 微脊不发达, 顶端小窝明显内陷;盐度5和30组线粒体丰富细胞胞质内存在发达的微细小管系统, 线粒体内脊丰富, 盐度20组胞质内微细小管系统分布不均匀, 结构松散, 部分收缩成珠泡状结构, 与粗面内质网相混杂。线粒体丰富细胞的结构变化与其所处的渗透压环境相适应。
Distribution and ultrastructural changes in the mitochondrion-rich cells in gills of artificial selected Trachinotus ovatus under different salinities (5, 20, and 30) were examined by light and transmission electron micrograph. Results indicated that the mitochondrion-rich cells were mainly present on the base of the gill filaments and branchial leaflets, and the volume and quantity of mitochondrion-rich cells increased with salinity. All three salinity groups had apical crypts, which were constituted by the mitochondrion-rich cells, pavement cells and accessory cells. Mitochondrion-rich cells in the salinity 5 group had large apical membranes with developed microridges and shallow apical crypts. Apical crypts in the salinity 20 and 30 groups had small apical membranes and undeveloped microridges, and were embolic obviously. Cytoplasm of mitochondrion-rich cells in the salinity 5 and 30 groups developed tubular systems and abundant cristae mitochondria. The tubular system of the salinity 20 group was non-spatially constant and had loose structure. Part of the tubular system contracted into a pearl bubble structure and shared rough endoplasmic reticulum. Mitochondrion-rich cells in Trachinotus ovatus under salinities 5 and 20 appeared both seawater-type’s and freshwater-type’s features, and those in salinity 30 had typical characteristics as seawater-type MR cells. Structural changes of mitochondrion-rich cells were suited to different osmotic pressure.