欧洲鳗鲡寄生鳗鲡肤孢虫的超微结构和组织病理特征

Ultrastructural and Histopathological Characteristics of Dermocystidium anguillae Spangenberg,1975 Infecting European Eel Anguilla anguilla Linnaeus,1758

为了完善鳗鲡肤孢虫(Dermocystidium anguillae Spangenberg,1975)形态学和组织病理学信息,进行扫描电镜和透射电镜观察,并研究该寄生虫对欧洲鳗鲡(Anguilla anguilla Linnaeus,1758)鳃组织的病理损伤。扫描电镜观察显示:鳗鲡肤孢虫孢子呈球形,大小均一;大部分孢子处于同一发育时期,个别孢子处于二分裂阶段;孢子被表面一层网状物质包裹;部分孢子可观察到分裂时形成的芽痕,芽痕上有多个不规则的凹陷。透射电镜观察显示:鳗鲡肤孢虫具有电子疏松的细胞壁;孢子内有较大的遮光体,液泡、细胞核、脂质空泡等细胞器位于遮光体一侧。组织病理分析显示:鳗鲡肤孢虫在宿主鳃丝中形成大量孢囊,孢囊挤压周围鳃组织,导致鳃丝融合、鳃小片脱落;孢囊具有一层嗜酸性孢囊壁;孢囊周围可见明显的炎性细胞浸润。

To improve the morphological and histopathological information of Dermocystidium anguillae Spangenberg,1975,scanning and transmission electron microscopes were used for related observation,and pathological damage of this parasite to gills of European eel Anguilla anguilla Linnaeus,1758 was studied.Scanning electron microscopy showed that spores of D.anguillae were spherical and uniform in size.Except few spores within binary fission,most spores were in the same developmental stage.Spore surface was covered by an unknown reticular substance.Fission bud scars with several irregular depressions were observed in some spores.Transmission electron microscopy revealed that spores of D.anguillae were enveloped by an electron-lucent cell wall.In addition,the spores were mostly occupied by a refractile body,with vacuoles,nucleus and lipid vacuole around it.Histopathological analysis found that a number of cysts of D.anguillae developed in gill filaments of European eels,which caused compression of adjacent gill tissue,fusion of gill filaments,and shedding of secondary lamellae.Cysts of D.anguillae were covered by an eosinophilic wall,around which obvious inflammatory cell infiltration occurred.