Effect of habitat fragmentation on survival and reproducibility of schistosome-transmitting snail Oncomelania hupensis in Anhui province, China

Abstract： Oncomelania hupensis is of great medical importance as the sole intermediate host of human blood fluke Schistosoma japonicum. Snail habitats in China are becoming increasingly fragmentation as a result of intensive environmental management. Two administrative villages, Anhui province, China were selected to assess the effects of habitat fragmentation on snail survival and reproducibility of snails. The snail habitats of Cao village were fragmented in 2002, and then the fragmentation degree of this village is higher that of Tangxi village. The proportion of qudrats with live snails in Cao village decreased from 87.7% in 2001 to 24.7% in 2010, and reducing by 71.8%, while the proportion of qudrats with live snails in Tangxi village increased from 16.8% in 2002 to 31.7% in 2010, and increased by 88.7%. The mean snail density of Cao village decreased from 5.60 snails / 0.11m2 in 2001 to 0.95 snails / 0.11 m2 in 2010, and reduced by 83.0%, while the mean snail densities of Tangxi village increased from 0.63 snails / 0.11m2 in 2001 to 2.85 snails / 0.11m2 in 2010. The mortality of snails in Cao village was always higher than that in Tangxi village, and the mean live egg density of snails in Cao village was always less than that in Tangxi village in 2009 and 2010. The snail habitats in the study area have exhibited visible fragmentation. Habitat fragmentation could reduce the snail population size and increase the mortality of snails.