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Kusatsu, Japan

Previous studies from southern Japan reported larval stages of eight gnathiid isopod species parasitising coastal elasmobranchs. Since gnathiid larvae of these different species closely resembled each other, it was necessary to obtain specimens of free-living adult males for identification to the species level. This was achieved by allowing larvae of the final stage to moult into adult males. From these males, specimens of a species new to science were discovered and described here as Gnathia rufescens n. sp. The main differentiating characteristics of G. rufescens n. sp. are: (i) the apex of pleotelson is oval shaped; (ii) the dorsal sulcus is wide in the posterior part; and (iii) the article 3 of the pylopod is not reduced in the male. Additionally, this paper summarises the specific pigmentation patterns of third-stage larvae of the new species and eight previously described species. Furthermore, host records and host use by the gnathiids were summarised based on data from 158 hosts and over 4,500 gnathiid samples; these are discussed with a focus on host-specificity of the nine gnathiid species studied. © 2015, Springer Science+Business Media Dordrecht. Source

Hu X.,Ocean University of China | Kusuoka Y.,Lake Biwa Museum
Acta Protozoologica | Year: 2015

Two oxytrichid freshwater ciliates, Apoamphisiella tihanyiensis (Gellért and Tamás, 1958) Foissner, 1997 and Notohymena australis (Foissner and O’Donoghue, 1990) Berger, 1999, were recorded for the first time in Lake Biwa, a 4-million-year-old lake located at the Shiga Prefecture in Japan. Their morphology was investigated based on observations of live and protargol-impregnated material. Based on the present observation and previous descriptions, A. tihanyiensis is characterized by having an elliptical body shape, yellowish cortical granules, two long frontoventral rows, enlarged frontal and transverse cirri, highly variable numbers of frontoventral, and postoral ventral cirri, and six to 11 caudal cirri arranged in three short rows. New data confirm the presence of pretransverse ventral cirri in this species. Morphologically, N. australis differs from its congeners in having the following combination of characters: greenish cortical granules, the cirrus V/2 located slight anterior to the leftmost transverse cirrus, dorsal kinety 3 almost as long as body, and seven to 10 caudal cirri arranged in three short rows. Morphogenesis in N. australis shows the same pattern as in N. apoaustralis but differs from that of other congeners in the origin of oral primordium and the formation of more than just three caudal cirri. © 2015, Jagiellonian University. All rights reserved. Source

Chang C.Y.,Daegu University | Lee J.,Daegu University | Smith R.J.,Lake Biwa Museum
Zootaxa | Year: 2012

Preliminary surveys of brackish and freshwater habitats in the southeast and east of South Korea produced a total of fifteen species. Ten of these species are new records for Korea, and one additional species, belonging to the genus Tanycypris, is newly described herein. Twenty-seven species of nonmarine ostracods are now reported from Korea, but this is probably only a small proportion of the actual number of species inhabiting the peninsula. The presence of Dolerocypris ikeyai Smith & Kamiya, 2006, Cryptocandona brehmi (Klie, 1934), Cryptocandona tsukagoshii Smith, 2011, Physocypria nipponica Okubo, 1990 and Vestalenula cylindrica (Straub, 1952) on the Korean Peninsula demonstrates that these species are also distributed on the continent, and are not endemic to Japan. Copyright © 2012, Magnolia Press. Source

A neotype is designated for the large and ecologically interesting species of Japanese earthworm, Drawida hattamimizu Hatai, 1930. Its morphological redescription is unambiguously combined with the neotype's sequence of the Cytochrome Oxidase I (COI) locus of the mitochondrial DNA, the first time an earth-worm species' type has been thus profiled. Probably it is an introduced exotic rather than a translocated native, with a patchy distribution that appears only partly defined in Japan where it is both a restricted and an endangered listed species. Brief comparison of sympatric Drawida japonica (Michaelsen, 1892) to the type-species Drawida barwelli (Beddard, 1886) - and this latter from Shiga appears as a new record for Japan - allows the diagnosis of Drawida Michaelsen, 1900 to be amended slightly. The contentious issue of molecular 'cryptic species' is queried in relation to the lack of molecular data from type-specimens, the unique name-bearing references employed in zoological nomenclature. Without such reference, neither eco-taxonomic nor genomic studies of earthworm taxa can progress. In this regard, questions are raised concerning the molecular identities and provisional divergences of cosmopolitan generotypes Allolobophora chlorotica chlorotica (Savigny, 1826), the Aporrectodea caliginosa (Savigny, 1826) species-complex sensu Blakemore (2002), and of ecotoxicological standard test-species icon Eisenia fetida fetida (Savigny, 1826). Resurrection of their respective synonyms is mooted. Resolution of relationships within and between earthworm genera and families without DNA testing of the representative type-species and type-genera is flagged as another crucial concern. Source

Gnathiid larvae were collected from the gill chambers of coastal sharks in southwestern Japan. Some were reared in a laboratory aquarium and successfully metamorphosed into adults. Morphological observations of the adult males identified three undescribed species, which are designated Gnathia albipalpebrata n. sp., G. parvirostrata n. sp., and G. dejimagin. sp. on the basis of their larval morphologies and pigmentation patterns. Copyright © 2014 Magnolia Press. Source

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