Comparative study of sheep and buffalo isolates of Fasciola gigantica in the intermediate host Lymnaea auricularia.

A comparison was made of the biological behaviour of two isolates of Fasciola gigantica, obtained from sheep and buffalo, in the aquatic snail Lymnaea auricularia. The sheep isolate exhibited a lower rate of infection, slower larval development and the production of fewer cercariae. Larger eggs, miracidia and metacercariae were obtained from the buffalo isolate while the rediae and cercariae were smaller. Metacercariae of sheep origin were dark brown with a mortality after 80 days of storage at 4 degrees C of 30.6 per cent while those of the buffalo isolate were straw coloured and had a mortality of 10.2 per cent.