Robertsiella silvicola, a new species of triculine snail (Caenogastropoda: Pomatiopsidae) from Peninsular Malaysia, intermediate host of Schistosoma malayensis (Trematoda: Digenea)

A new species of pomatiopsid gastropod, Robertsiella silvicola, is described from Perak, peninsular Malaysia. The encapsulation of the ducts of the bursa copulatrix complex, short (wide) spermathecal duct and penial stylet indicate that this is a species of Robertsiella. Robertsiella silvicola is distinguished from other Robertsiella by its small size, the lack of pronounced spiral macrosculpture on the shell, and the nature of the stylet. Robertsiella silvicola is found in water bodies ranging from small, spring-fed, first-order streams to tiny trickles of water draining off forested hillsides. This species appears restricted to limestone areas in the foothills of the mountain chains of Kedah and Perak States, West Malaysia. It appears to be a highly compatible intermediate host for the parasitic blood fluke Schistosoma malayensis Greer, Ow-Yang & Yong, 1980 that infects humans and other mammals in Malaysia.