Athanas anatidactylus sp. nov., a new alpheid shrimp (Crustacea: Decapoda) associated with crinoids in the tropical western Pacific. Zoological Studies 46(2): 162-167. Athanas anatidactylus sp. nov. is described on the basis of a holotype specimen collected in Nhatrang Bay, Vietnam, and an additional specimen from the Bohol Sea, the Philippines. The specimen from Nhatrang Bay was collected from a crinoid host. The new species is unique within the genus Athanas in having non-enlarged, symmetrical chelipeds ending in a peculiar claw with duckbill-shaped fingers, and the 3rd maxilliped having a broadened ultimate segment, distally armed with a row of strong spines. It is closely related to A. ornithorhynchus Banner and Banner, 1973, known as a facultative symbiont of filter-feeding brittle stars. An earlier report of a crinoid-associated Athanas (Bruce 1987) suggests that A. anatidactylus sp. nov. may also occur on the Great Barrier Reef, Australia. http://zoolstud.sinica.edu.tw/Journals/46.2/162.pdf