RESUMO
OBJECTIVE: To understand the possibility of the survival and reproduction of Oncomelania hupensis robertsoni snails in water network regions in Hubei Province, as well as their expected lifespan after leaving the original propagating environment, so as to provide the basic data and precondition for reducing the infection rates of O. h. hupensis in the lake regions. METHODS: The O. h. robertsoni snails, smooth-shell, were collected from Danling County, Sichuan Province,and raised in the cages in Baimasi Town of Jiangling County, Hubei Province. The survival and reproduction abilities of the snails were observed on regular time. The O. h. hupensis from Jiangling County, Hubei Province was studied as a control group. The expected lifespan of snails was calculated by using the animal life table. RESULTS: After 3-, 6-month, the survival rates of O. h. robertsoni were maintained more than 75% in the homogeneous and mixed living conditions, still above 20% after 9-month. Compared with the control group, there was a statistically significant difference in the 3-month group (Chi2 three months = 38.641, P < 0.05), there was a significant difference between the homogeneous and mixed groups for the female snail survival rates (Chi2af = 13.255, P < 0.05, Chi2cg = 4.882, P < 0.05), but not in the 6-, 9-month groups (Chi2 six months = 3.253, P > 0.05; Chi2 nine months = 5.017, P > 0.05). Filial generation snails were found after nine months in each group. The expected lifespan of 0. h. hupensis was 41.16 d and that of O. h. robertsoni was 35.84 d in the laboratory. CONCLUSIONS: The O. h. robertsoni snails from foreign lands can continually survive and reproduce in water network regions in Hubei. O. h. robertsoni snails have enough survival time to passive remote diffusion after leaving the original propagating environments.
