This study was undertaken in order to describe new and poorly known species of the
Perinereis nuntia species group (Nereididae: Polychaeta), which are concurrently being investigated genetically. Six species are described from intertidal waters of Taiwan and adjacent areas, including southern Japan, east-central and southeastern China, Singapore, Malaysia, and Indonesia (Java). These include
P. mictodonta (Marenzeller, 1879),
P. nuntia (Savigny, 1818),
P. rhombodonta (Wu, Sun and Yang, 1981), and 3 new species,
P. shikueii sp. nov.,
P. viridis sp. nov., and
P. wilsoni sp. nov. Literature records of
P. nuntia brevicirris from the region are referred to as
P. mictodonta; those of
P. nuntia vallata are referred to as
P. wilsoni sp. nov. All species can be distinguished by a combination of pharyngeal paragnath numbers and the arrangement, and length ratios of the dorsal cirrus to dorsal notopodial ligule of the anterior and posterior parapodia. A key to tropical and subtropical Indo-West Pacific species of the
P. nuntia species group is provided. All species inhabit intertidal sandy substrata under rocks or boulders, except
P. viridis sp. nov., which occurs on reef shores in rock crevices.
Perinereis wilsoni sp. nov. is found on rocky or reef limestone coasts, whereas the other 4 species occur mainly on sedimentary intertidal flats. The high diversity of the
P. nuntia species group in Taiwan is attributed to a combination of factors including intrinsic reproductive features and Taiwan's position straddling 2 major biogeographic regions: the tropical Indo-West Pacific and the temperate Japan-East China Sea. The present results reveal a degree of sympatry not previously reported for the genus.
