Description of Crinotonia anastasiae, new genus, new species, a new crinoid associated pontoniine shrimp (Crustacea: Caridea) from Nha Trang Bay, Vietnam, with inclusion of Periclimenes attenuatus Bruce, 1971, in the new genus

Crinotonia anastasiae, new genus, new species, is described on the basis of several specimens collected from a shallow water crinoid, Phanogenia gracilis (Hartlaub, 1893), in Nha Trang Bay, Vietnam. Crinotonia, new genus, differs from other pontoniine genera in the combination of several morphological features, including the absence of a podobranch on the second maxilliped, an arthrobranch on the third maxilliped; the presence of several robust disto-lateral and ventro-mesial teeth on the first segment of the antennular peduncle; the extreme dimorphism of the second pereiopods; third pereiopod with propodus having a serrated ventral margin, without distoventral spines, with a specialized dactylus. Crinotonia, new genus, is similar to the genus Pontoniopsis Borradaile, 1915 (type species P. comanthi Borradaile, 1915) which is also associated with crinoid hosts. All referred morphological features are also present in Periclimenes attenuatus Bruce, 1971, which is therefore assigned to Crinotonia, new genus. Crinotonia anastasiae, new species, differs from Crinotonia attenuatus (Bruce, 1971), new combination, mainly in the stouter body and appendages, and the presence of several spines along the ventral margin of dactylus of the third pereiopod.