The present study was carried out to obtain more information clarification of the susceptibility of the snails, Lymnaea pervia and L. auricularia to the common liver flukes, Fasciola hepatica and F. gigantica. The snails were collected from paddy field and irrigation route in a rural area located along the Han-gang riverside. Cercariae naturally shed from the snails were examined for identification for Fasciola spp. On the other hand, L. pervia and L. auricularia were artificially bred and the offsprings were divided into 3 groups according to day of age; baby snail group(5-7 days of age), young group(15-17) and adult group(more than 60), respectively, and used for infection of miracidia of F. hepatica and F. gigantica. The liver flukes were collected from Korea cattle and morphologically classified for the experiment. Eggs of F. hepatica and F. gigantica were cultured in the laboratory. After hatching, miracidia were used to infect the snails.
The results obtained in the present study were summarised as follows ;
1) Cercariae were naturally shed from both species of snails and cercariae of Fasciola spp. were found from 3(1.2%) among 250 individuals of L. pervia, but not from 200 individuals of L. auricularia.
2) Among 376 worms of Fasciola spp., 23(6.1%) were F. hepatica, 144(38.3%) were F. gigantica and 209(55.6%) were intermediate form, respectively.
3) Infection rates in the baby, young and adult snail group of L. pervia treated with F. hepatica miracidia were revealed as 57.6%, 53.1% and 47.9%, respectively, and with F. gigantica were 100.0%, 95.6% and 86.4%, respectively. The differences of infection rates between the corresponding groups of the former and the latter were highly significant(p<0.005). However. infection rates in the baby and young groups of F. hepatica- or F. gigantica-treated L. auricularia were very low, and no infection was established in the adult groups.
From the results. it is evidenced that L. pervia is the most suitable intermediate host for F. gigantica and F. hepatica in Korea.
