卵形半肠吸虫在贝类宿主体内发育的组织学观察

HISTOLOGICAL OBSERVATION ON THE DEVELOPMENT OF MESOCOELIUM OVATUM IN THE SNAILS BRADYBAENA SIMILARIS FERUSSAC

本文报道了卵形半肠吸虫Mesocoeliumovatum虫卵人工感染同型巴蜗牛 (Bradybaenasimilaris)后 ,在不同时间固定蜗牛 ,经石蜡包埋连续组织切片 ,观察卵形半肠吸虫幼虫期在蜗牛体内的发育情况。在感染10天的蜗牛体内发现早期母胞蚴 ,在感染 14天的母胞蚴体内出现早期子胞蚴胚球 ,感染 2 3天的子胞蚴已成形 ,体内可见尾蚴胚球 ;感染 2 6天子胞蚴体内的尾蚴胚球已明显增大 ,子胞蚴开始迁移。 37天的子胞蚴因体内尾蚴胚球数目增多而增大明显 ;4 0天的子胞蚴体内含大小不等的尾蚴胚体和胚球 ;感染 5 5天的蜗牛体内已可见到成熟的尾蚴和在子胞蚴体内成囊的后蚴。表明在夏季 ,人工感染蜗牛的情况下 ,卵形半肠吸虫在蜗牛体内发育成熟只需近

This paper reported the histological development of Mesocoelium ovatum in the snail Bradybaena similaris Ferussac. Snails were infected experimentally by feeding Mesocoelium ovatum eggs,5～6 snails were fixed in Bouins fluid at intervals of 3～6 days postinfection,the entire animal was dehydradted in ethanol toluol series,embedded in paraffin,serially sectioned at 10μm,and stained with Enlirchs hematoxylin eosin.The results:the germinal cells in the mother sporocyst stretched and scattered in 10 days postinfection snails,and the number of germinal cells increased.In the 14 th day postinfection snails,germinal cells created a large space around themselves and germinal balls were presented in mother sporocyst,each become a daughter sporocyst.On 20 th day postinfection mother sporocyst enlarged obviously,the number of germinal balls increased.On 26 th day postinfection,mother sporocyst scattered all over the intestine wall.The germinal balls lengthened at the both sides,and liberated from the mother sporocyst.The daughter sporocyst with a thick wall of a single layer of cells surrounded the cercarial germinal cells and balls. By 37 th day postinfection,the daughter sporocyst with different size of cercarial germinal balls enlarged significantly.After 40 days postinfection,the daughter sporocyst contained the different stages of the cercarial embryos.Some cercarial embryos began to mature in the daughter sporocysts.On 55 th day postinfection,the cercariae in daughter sporocyst were mature and metacercaria encysted in the daughter sporocyst.