A new species of Scolelepis (Polychaeta: Spionidae), highly abundant on the sand beaches of western Phuket Island, Thailand

Scolelepis (Scolelepis) laciniata n. sp. is described from the intertidal zone of sandy beaches along the west coast of Phuket Island, Thailand. It belongs to the group of species that lacks notopodia on the first setiger and lacks hooded hooks in all notopodia. The most striking character of the new species is the presence of 3-5 lateral fringes on the notopodial postsetal lamellae of anteriormost middle setigers. Furthermore, on most of these setigers 1-5 terminal and subterminal, clavate papillae are present on the branchiae. Ciliation on the palps is strongly reduced. During the height of the southwest monsoon season (especially July to October), the new species is the dominant element within the macrofauna of the intertidal zone just above median tide level. Scolelepis (S.) laciniata appears to be particularly plentiful at more protected sites.