The Indo-Pacific scorpionfish Scorpaenodes albaiensis (Evermann and Seale, 1907), for which the Philippines was previously the northernmost record, is recorded from East Asia (Taiwan and Japan) for the first time on the basis of 16 specimens. Specimens from Taiwan and Japan previously identified as S. minor (Smith, 1958) are shown to include the closely related species S. albaiensis as well. The East Asian specimens of S. albaiensis are described, and comparisons of the two species are made on the basis of Indo-Pacific specimens.
Satyrichthys rugosus (Fowler, 1943) was established with no comparison to other peristediid searobins. Our examination of types and other material of both S. rugosus and S. clavilapis (Fowler, 1938) has clarified that S. rugosus represents postlarvae and juveniles of the latter species. We therefore regard S. rugosus as a junior synonym of S. clavilapis and comment on its ontogenetic changes in morphology.
Stelgistrum mororane Jordan and Seale, 1906, previously synonymized with Stelgistrum stejnegeri Jordan and Gilbert, 1898, is here redescribed as a valid species of the genus Icelus. Contrary to the original description, the holotype of S. mororane has palatine teeth, which are diagnostic of Icelus but absent in Stelgistrum. Icelus mororanis comb. nov. is distinguished from all other species of Icelus by the following combination of characters: body relatively short; parietal spine undeveloped; subocular and supraocular spines absent; scales absent on cheek, between dorsal scale row and lateral line, and below lateral line except at pectoral axilla; small and simple cirrus present on upper rim of eye; two pairs of nuchal cirri present; and four saddles present on dorsolateral surface of body. Additionally, seven specimens of Stelgistrum stejnegeri collected from the Pacific coast of eastern Hokkaido are described, representing the first confirmed records of this species in Japanese waters.
A new species of brittle star, Asteroschema amamiense, is described from off Amami-oshima island, southwestern Japan. Asteroschema amamiense is distinguished from its congeners in having a single arm spine in each tentacle pore, both polygonal and elongated flat, plate-shaped dermal ossicles on the aboral periphery of the disc and basal portions of the arms, and radial shields composed of a single ossicle. Three species of Asteroschema, including this new species, and all the species of Astrocharis have plate-shaped dermal ossicles; a close relationship between all of these species is indicated. Moreover, single ossicle radial shields, which have not previously been reported for any species of Asteroschema, are found both in this new species and two species of Astrocharis.
We report new records from Japan for four species of freshwater Nematomorpha (Gordiida). Two species closely, but not exactly, resemble known species and were determined as Gordionus cf. lineatus (Leidy, 1851) and Parachordodes cf. okadai Inoue, 1955. The other two species are Chordodes japonensis Inoue, 1952 and Gordionus chinensis (Villot, 1874). All specimens were identified using scanning electron microscopy, with images given for Gordionus cf. lineatus and Parachordodes cf. okadai.
Three new species of free-living marine nematodes, belonging to three genera, Epacanthion Wieser, 1953, Enoplolaimus De Man, 1893 (both family Enoplidae Dujardin, 1845), and Oncholaimus Dujardin, 1845 (family Oncholaimidae Filipjev, 1916), are described from northern Japan. Epacanthion quadridiscus sp. nov. is most similar to Epacanthion enoploidiforme (Gerlach, 1953), E. gorgonocephalum Warwick, 1970, and E. georgei Inglis, 1971 in spicule length and the absence of a precloacal supplement, but differs from them in the shape of the gubernaculum and the arrangement of the subcephalic and cervical setae in the male. Enoplolaimus longigubernaculum sp. nov. differs from all of its congeners in having a long and straight gubernaculum. Oncholaimus secundicollis sp. nov. is distinguished from all of its congeners by the presence of a precloacal papilla, postcloacal papilla, and tail papilla in the male.