Oncomelania hupensis (Gastropoda: Rissooidea) in eastern China: molecular phylogeny, population structure, and ecology

Schistosoma japonicum risk in Jiangsu province, People’s Republic of China: identification of a spatio-temporal risk pattern along the Yangtze River

“…This two-peak transmission pattern is consistent with previous reports and can be explained by the evolvement of the snail populations and the length of the schistosome life cycle in P.R. China (Zhang et al, 1990;Wilke et al, 2000;Zhou et al, 2011). It means that cercariae were first shed from infected snails around June and infecting their definitive hosts around this time, providing the time needed to mature into worms and complete their life cycle resulting in a new generation of infected snails beginning the shedding cycle in September.…”

Conservation and variation in mitochondrial genomes of gastropods Oncomelania hupensis and Tricula hortensis, intermediate host snails of Schistosoma in China

“…But, the pairwise comparison only revealed a limited degree of variation (3.1% in mean genetic distance) between the two kinds of O. hupensis hupensis, which may support, at least to some extent, the opinion by Wilke et al (2000) that low genetic diversity existed between ribbed-shelled and smooth-shelled O. hupensis in mid-low reaches of the Yantgze River. Other authors also reported a low level of genetic variation between the ribbed-shelled, and smooth-shelled with varix, O. hupensis hupensis.…”

“…The taxonomy of O. hupensis in China has been a dispute for decades, due to the variation in shell sculpture, operculum, etc. (Liu et al, 1981;Davis et al, 1995;Wilke et al, 2000). In general, two morphotypes, i.e., ribbed-and smoothshelled O. hupensis can be distinguished.…”

“…In Yunnan and Sichuan Provinces, the snails are smaller, smooth-shelled with no varix, and are considered as the sub-species O. hupensis robertsoni (Liu et al, 1981;Davis et al, 1995Davis et al, , 1999a. In the middle and lower (mid-low) reaches of Yangtze River, another sub-species O. hupensis hupensis is distributed, and this sub-species is much longer than O. h. robertsoni, which however has varix, no matter whether the shell is ribbed or smooth (Davis et al, 1995;Wilke et al, 2000). In Fujian Province and Guangxi Autonomous region, the snails are smooth-shelled also with varix, but are assigned to the sub-species O. hupensis tangi (Davis et al, 1995), and recently snails distributed in Fujian and Guangxi were further separated as different sub-species (Li et al, 2009).…”

Phylogenetic relationships of the Emmericiidae (Caenogastropoda: Rissooidea)

“…It revealed a significant degree of saturation in the third position of the sequences. In rissooids, COI approaches saturation with about 18.6% or 120 nucleotide differences (DAVIS et al 1998, WILKE et al 2000a, which seems to happen after approximately 10 million years. However, to avoid a substantial loss of information in the case of closely related species, this position was not excluded from the dataset and it was used for the analysis.…”