[Research on living status of Oncomelania hupensis in autumn and winter and its correlates in Eastern Dongting Lake area].

OBJECTIVE: To explore the dynamic changes of Oncomelania hupensis snail densities in autumn and winter and the relationship between hydrological and meteorological factors and snail growth and decline.

METHODS: From Octobers to Decembers of 2007 to 2014, a bottomland close to eastern Dongting Lake was selected as the study field. The snails and elevation of the points were surveyed, and the hydrological and meteorological data were collected. The snail densities and death rates of every month were calculated. The meteorological and hydrological data were described, and the relationship between the snail densities and associated factors were fitted by the multiple regression model.

RESULTS: The snail density was highest in October 2012 (41.88 per 0.1 m2 ) and lowest in November 2008 (1.23 per 0.1 m2 ). The snail mortality was highest in November 2008 (73.72%) and lowest in October 2012 (1.09%). The multiple regression model found a linear relationship between hydrological and meteorological factors and snail densities. The correlation coefficient between the prediction of ln (snail density) and its measurements by using this model was 0.927 ( P = 0.001).

CONCLUSIONS: The average minimum temperature in January and time of starting flood have an obvious influence on the snail densities in autumn and winter.