多子小瓜虫的形态发生及其寄生导致翘嘴鳃组织病理变化

MORPHOLOGY AND MORPHOGENESIS OF ICHTHYOPHTHIRIUS MULTIFILIIS AND PATHOLOGICAL STUDY OF GILLS OF CULTER ALBURNUS

  • 摘要: 为阐明小瓜虫的形态发生及其对鳃组织的危害过程,本文开展了多子小瓜虫的光镜观察和翘嘴鲌鳃组织病理切片方面的研究。光镜形态研究发现小瓜虫运动时呈球形,直径500-800 m;前端具有耳廓状胞口和内陷的袋状胞咽;环境温度为18℃时,滋养体经1h左右发育成包囊,体表形成一层透明胶膜,并以虫体中央的分裂沟为界进行二分裂;子代虫体从8细胞期进入16细胞期时,包囊内部形成内胞膜将子代虫体等分为两个集团。组织切片结果显示虫体呈卵圆形,挤压了周围的包裹细胞,导致组织变形;鳃小片黏连,鳃丝上皮细胞受到破坏,严重区域鳃丝结构被完全破坏。本研究解析了小瓜虫的形态发生与发育过程以及对宿主危害的组织病理结构与机制,为揭示小瓜虫的侵染、发育和成熟规律奠定了理论基础,并为小瓜虫病害的有效防控提供理论资料。

     

    Abstract: Ichthyophthirius multifiliis, a widely distributed protozoan ciliate, can infect various aquatic animals and results in Ichthyophthiriasis to cause serious economic losses. In order to clarify the morphology and morphogenesis of I. multifiliis and the pathological injuries of gill caused by this parasite. In present study, we carried on a survey on morphology and morphogenesis of I. multifiliis trophont and gill histopathology caused by this parasite isolated from Culter alburnus. Under light microscopy, trophonts that removed from host tissue assumed a spherical shape with a diameter range from 500 to 800 m; ear-shaped cytostome and bag-shaped cytopharynx located in the anterior field; trophont encysted itself and transformed to tomont at 18 in 1h, and then underwent a rapid sequence of binary fission; a new endocystical membrane formed to separate the daughter cells into two equal groups during 8-cell stage to 16-cell stage. Pathological analysis indicates that I. multifiliis assumed oval in parasitic positions, stimulated and stressed the surrounded epithelial cells, caused deformation of tissue, adhesion of secondary gill and injuries of epithelial cells and even completely damaged the structure of gills. The present study provides detail description of morphology and morphogenesis of I. multifiliis and the mechanism of pathological injuries caused by this parasite, in order to lay the theoretical foundation for clarifying I. multifiliis invasion and development in the host and provide theory for treatment of Ichthyophthiriasis.

     

/

返回文章
返回