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Seoul, South Korea

Chertoprud E.S.,Moscow State University | Frenkel S.E.,Russian Federal Research Institute of Fisheries and Oceanography | Kim K.,Marine Act co. | Lee W.,Hanyang University
Journal of Natural History | Year: 2015

Based on novel data and a literature review, an inventory of Harpacticoida from the northern part of the East Sea and the southern part of Sea of Okhotsk is compiled. A total of 151 species belonging to 70 genera and 26 families, of which 16 species are deemed to be new to science, are recognized from the region. Twelve harpacticoid species assemblages are described from marine and brackish water soft sediments and the phytal zone. Estuarine faunas were similar throughout the East Sea and Sea of Okhotsk, both in species composition and dominant-taxon structure. Conversely, the fauna of marine soft sediment and phytal zones differed greatly throughout this region. This distinction may have been caused by differences in dispersal rates or by differences in environmental conditions. The distribution of littoral and sublittoral harpacticoids was determined primarily by climatic factors and the temperature of surface waters. Three basic sub-regions were distinguished within the survey area: Korean, which includes many tropical taxa (39%) and a smaller amount (about 20%) of boreal taxa; Primorye, where boreal and subarctic-arctic species (>40%) predominate, and representatives of the tropical complex are rare (17%); and Soya, with a mix of tropical (22%) and boreal (31%) faunal elements. The faunas of the Korean and the Primorye sub-regions are distinct, whereas that of the Soya has intermediate features. © 2015 Taylor & Francis Source

Hong J.-H.,Hanyang University | Hong J.-H.,Marine Act co. | Tchesunov A.V.,Moscow State University | Lee W.,Hanyang University
Zootaxa | Year: 2016

One new and one known species of the family Comesomatidae Filiepjev, 1918 were collected from marine sediments in the East Sea, Korea. Cervonema donghaensis sp. nov. is related to C. proximamphidum Tchesunov, 2000 and C. chilensis Chen & Vincx, 2000 but differs from them by the presence of the gubernaculum and by having outer labial setae and ce-phalic setae of unequal length. It differs from C. proximamphidum by having a rather shorter tail and the shape of the pos-terior widening of the pharynx, which has distinct muscular striation. Cervonema donghaensis sp. nov. differs from C. chilensis in body length, higher de Man's ratio c, and having a shorter cylindrical portion of the tail. Cervonema deltensis Hope & Zhang 1995 is considered as a junior synonym of C. tenuicauda (Schuurmans Stekhoven, 1950) Wieser, 1954. Specimens of Laimella filipjevi Jensen, 1979 from East Sea, Korea largely agree with the original description of Jensen (1979) of nematodes from the Western Baltic Sea, except for slight differences in length of cephalic setae and spicules. It also coincides well with the redescription of L. filipjevi by Tchesunov (2000) based on specimens from the White Sea. Pictorial keys for the identification of valid species in the genera Cervonema Wieser, 1954 and Laimella Cobb, 1920 are given. Copyright © 2016 Magnolia Press. Source

Karanovic T.,Sungkyunkwan University | Karanovic T.,University of Tasmania | Kim K.,Hanyang University | Kim K.,Marine Act co. | Lee W.,Hanyang University
Zootaxa | Year: 2015

Three new species of Enhydrosoma Boeck, 1873 are described from Korea, all found in muddy sediments in the sublittoral zone. They also all have a bifurcate rostrum, just like the type species of this genus, E. curticauda Boeck, 1872, and one recently described Korean representative, E. coreana Kim, Trebukova, Lee & Karanovic, 2014. These five species share a number of other morphological features, and mostly differ in details of integumental relief, caudal rami shape, and ornamentation of the male antennula. We aim to compare molecular and morphology-based phylogenies obtained for four Korean species of Enhydrosoma and two other members of the family Cletodidae: Geehydrosoma intermedia (Chislenko, 1978) from Korea and Russia and Stylicletodes sp.from Korea. Similar studies in other animal groups have helped to reevaluate the suitability of morphological characters for reconstructing phylogenetic relationships and taxonomic revisions, and the genus Enhydrosoma is considered to be polyphyletic and in urgent need of revision. We use partial sequences of the mtCOI gene for our molecular phylogeny and 32 non-additive characters for our morphology-based phylogeny. High congruence between all cladograms suggests that reconstructing phylogenetic relationships in this group of harpacticoids may be straight-forward, but highlights as homoplastic some morphological characters previously considered important for defining supraspecific taxa in this family. On the other hand, some characters previously overlooked in species descriptions show a significant phylogenetic signal. Even though there is no doubt about the monophyly of the Korean Enhydrosoma, their high average pairwise maximum likelihood distances suggest only a remote relationship, and explain their sympatry and/or parapatry. Weak bootstrap support for our basal nodes in molecular phylogenies shows limitations of a single-gene approach, and probably cannot be resolved without a wider taxon and character sampling. Wider taxon sampling will also be necessary to improve bootstrap values of basal nodes in morphology-based cladograms. Copyright © 2015 Magnolia Press. Source

Lee K.,Marine Act co. | Kim K.,Hanyang University | Lee W.,Hanyang University
Proceedings of the Biological Society of Washington | Year: 2014

The damaging effect of mid-ultraviolet (UVB, 280-315 nm) radiation on a marine copepod, Tigriopus japonicus sensu lato was investigated. Copepods were collected from tidal pools on rocky shores, Yeosu, on the south coast of Korea, and were cultured under constant conditions (temperature: 20°C, salinity: 20 psu, L : D = 12 : 12 h) in the laboratory. Each stage of nauplius (N1-N6) and copepodite (CI-CVI) was harvested from the culture and exposed to one of eight irradiation doses (1, 5, 10, 15, 20, 25, 30, and 35 kJ m-2) of UVB. No deleterious effect was induced by UVA or PAR. Extensive morphological deformities were observed, i.e., shrunken body (in groups 5 kJ m-2 at N4; 1 and 15 kJ m-2 at CI), in the urosome and caudal rami (5 and 15 kJ m-2 at N6; 10 kJ m-2 at CI), in the swimming legs (5, 10, and 15 kJ m-2 at CI; 10 kJ m-2 CIV), and in the antennule (5 kJ m-2 at CIII; 1 kJ m-2 at CIV). The types of deformity observed depended on the developmental stages of copepods that were exposed to UVB radiation. UVB radiation had a damaging effect on the morphology of T. japonicus s. l. Exposure of earlier larval stages to mid-ultraviolet affected the shape of the entire body, and the prosome shape was abnormal. Exposure of later larval stages to mid-ultraviolet resulted in abnormalities at the appendage level, i.e., in the antennules and swimming legs. Source

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