The Aphroditoidea collected during two joint expeditions of the Forschungsinstitut Senckenberg, Frankfurt, Germany, and the Institute of Oceanology, Chinese Academy of Sciences, Qingdao, conducted in autumn of 1990 and spring of 1992 to Hainan Island, South China Sea, are presented herein. Altogether 386 specimens of Aphroditoidea (Annelida, Polychaeta) belonging to 35 species were identified. Families represented are the Acoetidae Kinberg, 1856 (1 species), Aphroditidae Kinberg, 1856 (2 species), Polynoidae Kinberg, 1856 (27 species), and Sigalionidae Kinberg, 1856 (4 species). Identification keys to the representatives of the latter two families are given. Of the 35 species, six, including one genus, are new to science: Russellhanleya striata gen. nov. et sp. nov., Harmothoe liaoi sp. nov., Harmothoe sinensis sp. nov., Lepidonopsis collinifer sp. nov., Subadyte micropapillata sp. nov., and Verrucapelma conifera sp. nov. Two poorly known species are redescribed: Paralentia annamita (Fauvel, 1934) and Lepidonotus hainanicus Uschakov, 1982, the latter having been originally described as L. dentatus hainanicus, but raised to species level herein. Eleven of the 35 species (more than 30%) represent new records for Hainan Island, with four of them being new to the South China Sea in general.
Paraphiloconcha meretricis Yamaguti, 1936, an incompletely known lichomolgid copepod living in the pericardium of the hard clam Meretrix lamarckii Deshayes, 1853, is redescribed from the southeastern coast of Japan. Although the genus Paraphiloconcha is closely related to Philoconcha, it can be differentiated from the latter by the presence of large lateral processes on the metasomites, a three-segmented maxilliped, and relatively more developed leg setation. In consideration of the morphology and development of mollusk-associated lichomolgid genera, Philoblenna and Briarella, both of which have been assigned to the family Philoblennidae until now, are transferred to the Lichomolgidae.
Critical examination of specimens referred to Pagurus conformis De Haan, 1849 or P. megalops (Stimpson, 1858) has revealed that the two taxa are conspecific and that the former species has frequently been misidentified. Pagurus conformis, the senior synonym of P. megalops, is redescribed and illustrated in detail and compared with three allied species, P. cavicarpus (Paul'son, 1875), P. carpoforaminatus (Alcock, 1905), and P. spinulentus (Henderson, 1888). The taxonomic identities of species to which the name P. conformis has been incorrectly applied are discussed.
A new species of the proturan genus Eosentomon, E. rishir, is described from Rishiri Island, Hokkaido, northern Japan. The present species is characterized by the position and/or shape of sensilla c' and b on the foretarsus, the absence of A5 on abdominal tergites IV-VII, and the position and shape of P1a on tergites II-VII. An updated key to the Japanese species of Eosentomon is presented.
Scythropochroa radialis Lengersdorf, 1926 is recorded from Japan (Honshu and Kyushu) as the first representative of this genus from East Asia. The female of this species is redescribed based on the Japanese specimens and compared with a closely similar species, S. gressitti Steffan, 1969 from Micronesia. The egg and xylophagous larva of S. radialis are described for the first time. The biology and larval morphology of Scythropochroa are briefly discussed.
Two specimens of a flathead fish, Grammoplites knappi Imamura and Amaoka, 1994, were collected from the coasts of Kochi and Tokushima Prefectures, southern Japan. Reported here for the first time from Japan, this species has been known only from the South China Sea off Thailand, Malaysia, and China. Intraspecific variation in some proportional measurements and in the serration on the pterotic ridge are probably related to the immature condition of the present specimens.