Twelve new species of the streptaxid snail genus Discartemon Pfeiffer, 1856 are described from southern Thailand and western Malaysia, D. afthonodontia sp. n., D. circulus sp. n., D. deprima sp. n., D. discadentus sp. n., D. discamaximus sp. n., D. expandus sp. n., D. flavacandida sp. n., D. kotanensis sp. n., and D. megalostraka sp. n. from southern Thailand, as well as D. conicus sp. n., D. epipedis sp. n. and D. triancus sp. n. from western Malaysia. All 15 previously described species are revised and commented upon based on examined material. Streptaxis paradiscus Möllendorff, 1900 is considered a junior subjective synonym of the type species D. discus (Pfeiffer, 1853). Details of the genital anatomy of twelve species, and the radula and pallial system, are provided for the first time. An identification key is provided.
Angiostrongylus vasorum is a highly pathogenic metastrongylid nematode affecting dogs, which uses gastropod molluscs as intermediate hosts. The geographical distribution of the parasite appears to be heterogeneous or patchy and understanding of the factors underlying this heterogeneity is limited. In this study, we compared the species of gastropod present and the prevalence of A. vasorum along a rural-urban gradient in two cities in the south-west United Kingdom.