Sixteen deepwater eelpout species were collected from a trawl fishery survey conducted by a joint Japanese-Peruvian team between 1998 and 2003 off Peru. Two are described here as new to science. Lycenchelys imamurai sp. nov. is distinguished from congeners in the area by its unique lateral line configuration, two pelvic-fin rays, lack of head and nape scales, head pore pattern, and counts of the axial skeleton. Pachycara dolichaulus sp. nov. is distinguished from its congeners in the area by its lateral line configuration, low vertebral count, dorsal-fin origin, five postorbital pores, and lack of nape scales.
A single specimen of the rare cottid fish, Artediellus aporosus Soldatov, 1921, was collected from the Sea of Okhotsk off Esashi, Kitami, Hokkaido, Japan. The species is characterized by having a soft body covered with loose skin, nasal bones concealed under the skin with no or rudimentary spines, and no sensory pores on top of the head. The identification of the present specimen has been confirmed by a comparison with the type series of the species. Although this species has been reported from the Sea of Okhotsk and the northern Sea of Japan, the present specimen represents the first record of it from Japanese waters. Differences between A. aporosus and the close relative A. miacanthus Gilbert and Burke, 1912 are discussed.
Amathillopsis takahashiae, a new amphipod species of the family Amathillopsidae from Japan, is described and illustrated. This is the first record of this family from Japan. The new species differs from the known species of Amathillopsis by the combination of eyes being present and pereonites 1-4 lacking middorsal teeth.
Two new species of vestimentiferan tubeworm collected from the Brothers Caldera in the Kermadec Arc, South Pacific Ocean, are described here, based on morphological and molecular analyses, including sequence comparisons of over 600bp of the mitochondrial COI gene. Lamellibrachia juni sp. nov. differs from congeneric species in having flexible and thin-walled tubes, up to three pairs of lamellar sheaths, and similarly sized cuticular plaques on the vestimentum and trunk. Oasisia fujikurai sp. nov. differs from its sole congener in having eight pairs of branchial lamellae instead of up to 20. Oasisia and Ridgeia are shown likely to constitute a monophylum, but are retained as separate genera for now. The relationships between this clade and the genera Tevnia and Riftia remain unresolved. Within the monophyletic genus Lamellibrachia, L. juni sp. nov. is closest to L. sp. L7 from the Manus Basin.
Lake Kurilskoe (77.05km^2, maximum depth 316m; 104m above sea level) is an oligotrophic caldera lake on the southern Kamchatka Peninsula, Russian Far East. The littoral zone is devoid of macrovegetation. During a hydrobiological study in 1994-1998, 43 taxa of oligochaetes were found, 26 of them identified to the species level. The littoral zone was inhabited mostly by the Enchytraeidae, Lumbricillus pagenstecheri (Ratzel, 1869), L. arenarius (Michaelsen, 1889), Mesenchytraeus kuril Healy and Timm, 2000, Marionina charlottensis Coates, 1980, and M. klaskisharum Coates, 1983. Propappus arhynchotus Sokolskaya, 1972 and Haplotaxis gordioides (Hartmann, 1821) were also sometimes abundant. Naidinae included a large form of Nais communis Piguet, 1906, together with N. variabilis Piguet, 1906, N. pardalis Piguet, 1906, and Pristina aequiseta Bourne, 1891. Tubificidae s.s. and Lumbriculidae preferred the deeper littoral and sublittoral areas of the lake. The profundal zone was inhabited by Embolocephalus kurenkovi (Sokolskaya, 1961), Limnodrilus profundicola (Verrill, 1871), Tasserkidrilus americanus (Brinkhurst and Cook, 1966), and Styloscolex opisthothecus Sokolskaya, 1969, all in great abundance. Many oligochaete species widely distributed in nearby regions were not found in this lake.
Two species of parasitic nematodes, both associated with the Japanese clawed salamander Onychodactylus japonicus (Houttuyn, 1782) (Caudata: Hynobiidae), are treated in this paper. The first, Angiostoma onychodactyla Bursey and Goldberg, 2000 (Rhabditoidea: Angiostomatidae), is redefined as having an elliptical oral aperture without lips; double lateral alae; and male caudal papillae comprising nine pairs of pedunculate papillae, a single sessile papilla anterior to the anus, and two minute projections on the posterior anal lip. A new genus, Shunyanema, is established for Parapharyngodon japonicus Bursey and Goldberg, 1999 (Oxyuroidea: Pharyngodonidae). The new genus is characterized by the didelphic amphidelphic genital system, the vulva situated in the middle region of the body, and the anteriorly directed vagina in females; the absence of a V-shaped sclerotized structure supporting the genital cone in males; and the lack of an operculum and filaments in the eggs. Shunyanema japonicum comb. nov. is also redescribed and illustrated in detail.
Two new species of dicyemid mesozoan are described from Amphioctopus areolatus (de Haan, 1840) collected off Irino in Tosa Bay, southern Shikoku, and off Akashi in Osaka Bay, Honshu, Japan. Dicyema balanocephalum sp. nov. is a species of medium size that reaches about 1500μm in length. The vermiform stages are characterized by 19-21 peripheral cells, an elongate calotte, and an axial cell that extends to the base of the propolar cells. Infusoriform embryos consist of 37 cells; two nuclei are present in each urn cell, and the refringent bodies are solid. Dicyema leiocephalum sp. nov. is a species of medium size that reaches about 2000μm in length. The vermiform stages are characterized by 22 peripheral cells, a conical, smooth-surfaced calotte, and an axial cell that extends to the base of the propolar cells. Infusoriform embryos consist of 37 cells; two nuclei are present in each urn cell, and the refringent bodies are solid. This is the first report of dicyemids in A. areolatus.