An ecological study of Bithynia snails, the first intermediate host of Opisthorchis viverrini in northeast Thailand

Freshwater habitats of ponds, streams and rice paddies possess significantly different abiotic water qualities, which may account for the differences in Bithynia snail abundances. •Snail population and distribution is affected by biotic and abiotic factors.•Different snail habitat types possessed significantly different water qualities.•B.s. goniomphalos snails were more dominant in rice paddy habitats.•B.s. goniomphalos and F.m. martensi snail populations were negatively correlated.•Rice planting practices regulate snail population dynamics at rice paddy habitats. Infection with the food-borne trematodiasis, liver fluke Opisthorchis viverrini, is a major public health concern in Southeast Asia. While epidemiology and parasitic incidence in humans are well studied, ecological information on the O. viverrini intermediate hosts remains limited. This study aimed to investigate the factors affecting the distribution and abundance of the first intermediate host, Bithynia siamensis goniomphalos snails. Water quality and snails were sampled in 31 sites in Muang District, Khon Kaen Province, Thailand from June 2012 to January 2013 to characterize the B.s. goniomphalos snail habitats. Species relative abundance and Shannon's diversity and evenness indices were employed to describe snail compositions and diversities across different habitat types. Statistical analyses were conducted to examine the extent to which the water quality variables and species interactions account for the relative abundance of B.s. goniomphalos snails. The results showed that the freshwater habitats of ponds, streams and rice paddies possessed significantly different abiotic water qualities, with water temperature and pH showing distinct statistical differences (P