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1.
PeerJ ; 8: e10007, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33024639

RESUMO

We collected an undescribed laophontid copepod from a coarse sand habitat on the east coast of Korea and named it Quinquelaophonte enormis sp. nov. We compared the detailed morphological characteristics of the new species with those of congeneric species. Among them, the new species shows a superficial resemblance to the Californian species Quinquelaophonte longifurcata Lang, 1965. However, the two species are easily distinguishable by the setation of the syncoxa on the maxilliped and the fourth swimming leg. The new species has the variable setation on the second to fourth swimming legs. The variations appear among individuals or between the left and right rami of a pair of legs in a single specimen. Although complex chaetotaxical polymorphism occur in this new species, we used myCOI and Cytb to confirm that the new species is not a species complex. Also, partial sequences of 18S and 28S ribosomal RNA genes were used to analyze the position of the new species within the family Laophontidae. The new speciesis the fourteenth Quinquelaophonte species in the world and the second species in Korea.

2.
PeerJ ; 8: e9037, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32377453

RESUMO

During a survey of intertidal zones at beaches on Jeju Island, two species belonging to the family Thoracostomopsidae were discovered. One new species, Enoploides koreanus sp. nov. and one known species, Epacanthion hirsutum Shi & Xu, 2016 are reported. Along with morphological analysis, mitochondrial cytochrome oxidase c subunit 1 (mtCOI) sequences and 18S rRNA sequences of the species were also obtained and used to check relative p-distance and phylogenetic positions. While most species of Enoploides have long spicules, the new species belongs to a group of Enoploides with short spicules < 150 µm). Of the seven species with short spicules, the new species is most closely related to E. disparilis Sergeeva, 1974. They both have similar body length, fairly similar sized and shaped spicules with small gubernaculum running parallel to distal end of spicule, and an index value of b. The new species can be distinguished from E. disparilis by having pre-anal supplementary organ with short conical tail, while E. disparilis lacks pre-anal supplementary organ and has a long conico-cylindrical tail. Along with the description of the new species, the genus Enoploides Ssaweljev, 1912 is bibliographically reviewed and revised. Of 45 species described to date, 27 are now considered valid, 16 species inquirendae due to inadequate descriptions and ambiguity of the material examined, along with two cases of nomen nudum. With this review, we provide an updated diagnosis and list of valid species, a tabular key comparing diagnostic characters of all valid species, and a new complete key to species. One known species, Epacanthion hirsutum Shi & Xu, 2016, is reported in Korea for the first time. The morphology agrees well with the original description provided by Shi & Xu, 2016. As they had already reviewed the genus at the time of reporting four Epacanthion species, we provide only a description, depiction, and measurements for comparison purposes.

3.
PeerJ ; 8: e8506, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32095348

RESUMO

A new species of Sarsamphiascus Huys, 2009 was collected from sandy sediments of Hawaii at 12 -18 m depth. While the new species, Sarsamphiascus hawaiiensis sp. nov., is morphologically most closely related to S. kawamurai (Ueda & Nagai, 2005), the two species can be distinguished by the combination of the following morphological characteristics: elongated segments of the antennule in the new species, type of outer setae of the P5 exopod (bare in S. kawamurai), position of the inner seta of the P5 exopod in both sexes (more proximal in S. kawamurai), length and type of the setae of female P6 (shorter and bare in S. kawamurai). This is the first species of Sarsamphiascus from Hawaii to be discovered. Molecular analyses of mitochondrial cytochrome c oxidase subunit I (mtCOI) and nuclear 18S ribosomal RNA (18S rRNA) genes confirmed that S. hawaiiensis and S. kawamurai are distinct species.

4.
Environ Monit Assess ; 192(2): 81, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897611

RESUMO

Ecological quality (EcoQ) status of the Southwest and West coasts of South Korea was evaluated within the "National Investigation of Marine Ecosystems in Korea" in the 2015. In particular, the study dealt to assess the ecological quality of the sediments using free-living nematode communities. A total of 149 species were found in the study area, and Daptonema, Sabatieria, Parodontophora, Sphaerolaimus, and Viscosia were found as dominant genera. Statistical analysis of both environmental and faunal parameters showed an increasing human pressure from Western to Southern coasts. The community structure changed with the environmental features of the study area and allowed the detection of a suite of possible nematode indicators that might be used in monitoring studies. In particular, Dorylaimopsis spp. appeared heavy metal and organic matter resistant taxa, Sabatieria an eutrophication resistant genus, while Paracanthonchus and Neotonchus as heavy metal and organic matter sensitive genera. The principal component analysis (PCA) results showed a clear negative correlation between maturity index and both heavy metal and organic matter increasing, while diversity indices did not appear to be significantly influenced by them. Appling the thresholds of the synthetic nematode indices, the EcoQ of the study area was assessed as poor to moderate.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Nematoides/fisiologia , Poluição da Água/análise , Animais , Ecologia , Eutrofização , Sedimentos Geológicos/química , Atividades Humanas , Metais Pesados , República da Coreia
5.
Zootaxa ; 4896(2): zootaxa.4896.2.2, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33756862

RESUMO

Two new planktonic ostracods of the genus Proceroecia Kock, 1992, P. hwanghaensis sp. nov. and P. joseondonghaensis sp. nov., collected from neritic waters off the south coast of South Korea are described. Morphologically, they are similar to P. microprocera (Angel, 1971), the type species of the genus, but show several clear morphological differences, most prominent being the shape of the male endopodite on the second antenna and the presence of a sensilla on the coxale of the fifth limb. The two new species have subtle differences, such as the length of the frontal organ, number of spines on the comb-like e-seta on the first antenna in males, number of spinules on the b-seta on the second antenna in females, etc. Sequences derived from partial mitochondrial cytochrome oxidase c subunit 1 (mtCOI) for these novel species have been compared with sequences available for other Proceroecia species on GenBank, including P. microprocera. These comparisons suggest that both new species are distinct taxa. They also indicate that one set of sequences on GeneBank previously attributed to P. microprocera and derived from material collected from Chinese waters, belong to P. hwanghaensis, and that another set of sequences of an unidentified Proceroecia species from the South China Sea can be attributable to P. joseondonghaensis. Hence, these new species occur widely in the neritic waters of East Asia. The present study increases the number of the known Proceroecia species to nine, and the numbers of halocyprid ostracod species recorded from Korean waters to six.


Assuntos
Crustáceos , Plâncton , Animais , Crustáceos/genética , Feminino , Masculino , República da Coreia
6.
Zookeys ; 893: 69-89, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31844400

RESUMO

A new species in the genus Acartia, Acartia nadiensis sp. nov., is described from Fijian coastal waters. This species belongs to the subgenus Odontacartia based on the following morphological features: presence of a rostral filaments, a pointed process on the last prosomite, a serrated terminal spine on female P5, and the absence of a protrusion on the basis of the male right P5. This new species can be differentiated from its congeners by the combination of the absence of a spine on the first segment of the antennules, the short outer seta of female P5, and a medial spine on the exp-2 of the left male P5. Phylogenetic analyses using mitochondrial COI partial sequences show that the new species is distinct from its congeners.

7.
PeerJ ; 7: e8023, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31763070

RESUMO

A new species of the genus Mesacanthion Filipjev, 1927 was discovered during a survey of natural beaches of Jeju Island in South Korea. The new species Mesacanthion jejuensis sp. nov. shares general morphology of the genus such as the outer labial and cephalic setae being situated at the middle of cephalic capsule, well-developed mandibles with two columns united by a curved bar, and three equally sized and shaped teeth shorter than the mandibles. The new species belongs to a group of Mesacanthion species in which spicules are shorter than two anal body diameters. The new species is most closely related to M. pannosum, first discovered in Puget Sound, Washington, in terms of having enlarged cervical setae flap at the end of cephalic capsule, spicules which are shorter than 2 anal body diameter, both supplementary organ and gubernaculum. It can be distinguished from M. pannosum by its stronger inner labial setae, longer outer labial setae, and difference in the index value of b and c'. Along with the description of Mesacanthion jejuensis sp. nov., the genus Mesacanthion Filipjev, 1927 is bibliographically reviewed and revised. Including the new species, a total of 48 species are described within the genus; 39 which are valid; eight which are considered to be species inquirenda due to misplacement of genus and poor description; one which is considered nomen nudum. An updated diagnosis of the genus is provided along with a compiled tabular key comparing different diagnostic morphological characters of all valid species, as well as a pictorial key consisting of 21 species with spicules shorter than two anal body diameters.

8.
Zootaxa ; 4563(3): zootaxa.4563.3.6, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-31716532

RESUMO

A new species of the genus Thalassironus de Man, 1889 was discovered during several surveys of the offshore marine ecosystem in Korea. This new species belonging to the family Ironidae, Thalassironus koreanus sp. nov., shares general morphological traits of the genus such as an optically smooth cuticle, buccal cavity consisting of two parts with three movable teeth and thick cuticularized walls, six rounded lips with ten cephalic setae, slit-like amphid and short conical tail with caudal glands present. The new species is most closely related to T. bohaiensis, first discovered in the Bohai Sea, in terms of body ratio (a, b, c, c') and general morphology, but differs by its generally longer and larger body structures, cervical setae at the level of the buccal cavity, paired somatic setae distributed along the body, and longer/larger spicule. A description of Thalassironus koreanus sp. nov., diagnosis of the genus, emended pictorial key for the genus and discussion of important characteristics for the genus is provided.


Assuntos
Enoplídios , Nematoides , Animais , Ecossistema , República da Coreia
9.
Zookeys ; 832: 35-56, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30930644

RESUMO

A new interstitial species, Caecianiropsisgoseongensis sp. n. is described from littoral off the east coast of Korea (Sea of Japan). The species can be distinguished from its congeners by the number of antennular articles, shape of the male appendix masculina, setation of pereopods, and length ratio of the uropodal rami. To aid species identification a taxonomic key to all species of Caecianiropsis Menzies & Pettit, 1956 is also provided as well as a partial 16S mitochondrial ribosome RNA of the new species, which is the first genetic information for the genus.

10.
PeerJ ; 7: e6642, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30923656

RESUMO

We describe a new agglutinated monothalamous foraminiferal species, Capsammina crassa sp. nov., based on integrated observations of the test morphology and the chemical characteristics of materials composing the test. The new species was found at a depth of <60 m on the East coast of Korea. The test morphology is typical of the genus Capsammina, comprising two or more mica plates with a ring of finely agglutinated mineral grains sandwiched between them and surrounding the cell body. There is no distinct test aperture. Elemental analyses of the agglutinated grains revealed 15 different types of mineral grains of which quartz is the most abundant. The surface areas of grains exposed on fractured surfaces ranged from 1.6 to 7,700 µm2 and the large plate-like grains forming the upper and lower surfaces measured about 420-2,350 µm in maximum width. The new species is morphologically similar to C. patelliformis, however, the differences in size, distribution area and depth support that these two species are distinct. This discovery is the first record of the genus Capsammina from the North Pacific. Therefore, it extends the biodiversity and geographical distribution of the genus Capsammina, which has been reported only from the bathyal NE Atlantic. Our finding also suggests the possibility of additional discovery of monothalamous foraminifera from around Korea.

11.
Zookeys ; (814): 33-51, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30651711

RESUMO

Male monstrilloid copepods belonging to the genus Caromiobenella Jeon, Lee & Soh, 2018 were collected from Chuja Island, Jeju, Korea, using a light trap. This paper describes a new species, Caromiobenellaohtsukai sp. n., based on the display of reduced, knob-like fifth legs on the ventral side of the first urosomal somite. A unique combination of male genitalia features and number of caudal setae further confirms its specificity. Molecular analysis based on two partial gene sequences of mitochondrial cytochrome c oxidase subunit I (mtCOI) and 28S ribosomal RNA (28S rRNA) also supports the designation of this species by showing a relevant divergence from known congeners. Caromiobenellaohtsukai sp. n. is the ninth member of this genus and also the ninth monstrilloid reported from Korea.

12.
Mol Phylogenet Evol ; 130: 366-379, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30308279

RESUMO

Nannopus (Harpacticoida, Nannopodidae) species are abundant and widely distributed throughout the world across a variety of habitats. Nannopus is well known for high frequencies of misidentifications and thus may comprise several cryptic complexes and morphologically distinct species. Cryptic taxa are common in meiofauna communities. In this study, we aimed to identify Nannopus species using an integrative approach including molecular taxonomy. We adopted a non-destructive DNA extraction method so that morphological and molecular data could be obtained from the same specimen. We analyzed the molecular diversity and distributions of Nannopus using a total of 190 individuals. We sequenced the 190 mtCOI, 53 mtCYTB, 25 18SrDNA, and 43 28SrDNA genes from 190 individuals. Several species delimitation approaches were applied, including uncorrected p-distances for mtCOI, mtCYTB, 18SrDNA, and 28SrDNA, and Automatic Barcode Gap Discovery and Bayesian implemented Poisson tree processes for mtCOI and mtCYTB data. The maximum likelihood and Bayesian approaches were used to examine the phylogenetic relationships among individuals using the combined set of all four genes. Our species delimitation and phylogenetic analyses indicated the presence of three cryptic and six morphologically distinct species. All species are sympatric and widely distributed across mudflats ranging from the Yellow Sea to the South Sea in Korea. The divergence patterns of the four genes were not congruent. A phylogenetic tree based on the concatenated dataset was the most robust, was congruent with morphology, and suggested two major clades. We considered the validity of reinstating the genus Ilyophilus (Lilljeborg, 1902) and ultimately concluded that including all congeners in Nannopus until the type species (N. palustris Brady, 1880) is re-described was the most prudent approach.


Assuntos
Biodiversidade , Copépodes/classificação , Água do Mar , Animais , Sequência de Bases , Teorema de Bayes , Código de Barras de DNA Taxonômico , Bases de Dados Genéticas , Geografia , Filogenia , República da Coreia , Análise de Sequência de DNA , Especificidade da Espécie
13.
PeerJ ; 6: e4938, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29915690

RESUMO

Two forms of the monstrilloid copepod, one represented by males, the other by females, were dominant among the monstrilloids collected while sampling zooplankton with a light trap in southern coastal waters of Korea. Morphological examination revealed that the males are conspecific with the previously reported and rather specialized Korean species Monstrillopsis longilobata Lee, Kim & Chang, 2016, hitherto known only from males that have extremely long genital lappets. The females also show several diagnostic features of Monstrillopsis, such as prominent eyes, bilobed fifth legs with the inner lobe unarmed and reduced, and four urosomal somites. In addition, though, these females are extraordinary among all Monstrilloida in that their ovigerous spines are directed ventrally, not posteriorly as in most species or anteriorly as in those assigned to Maemonstrilla. Genetic divergence analyses based on partial mitochondrial cytochrome c oxidase subunit I, complete Internal Transcribed Spacer 1 (ITS1)-5.8S-ITS2, and partial 28S rRNA revealed little or no genetic divergence between the present males and females, thus demonstrating that they are mutually conspecific. The present report (1) provides the first morphological description of female M. longilobata with the proposal of a revised nomenclature for antennular setal armament; (2) presents the molecular evidence for conspecificity of the males and females; and (3) lists several morphological characteristics that are sexually dimorphic in this species, and thus likely also in other monstrilloids. Matters bearing on the validity of the genera Haemocera, Monstrillopsis, and Maemonstrilla are discussed.

14.
PeerJ ; 6: e4979, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29915699

RESUMO

The ectosymbiotic copepods, Vostoklaophonte eupenta gen. & sp. nov. associated with the sea cucumber Eupentacta fraudatrix, was found in the subtidal zone of Peter the Great Bay, East/Japan Sea. The new genus, Vostoklaophonte, is similar to Microchelonia in the flattened body form, reduced mandible, maxillule and maxilla, but with well-developed prehensile maxilliped, and in the reduced segmentation and setation of legs 1-5. Most appendages of the new genus are more primitive than those of Microchelonia. The inclusion of the symbiotic genera Microchelonia and Vostoklaophonte gen. nov. in Laophontidae, as well as their close phylogenetic relationships, are supported by morphological observations and molecular data. This is the third record of laophontid harpacticoid copepods living in symbiosis with sea cucumbers recorded from the Korean and Californian coasts.

15.
Zootaxa ; 4360(1): 1-66, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29245452

RESUMO

Five Nannopus Brady, 1880 species that are new to science are described from the intertidal mudflats of the Korean West Coast, Yellow Sea (South Korea). Nannopus minutus sp. nov. and N. dimorphicus sp. nov. belong to a group of species defined by seven elements on P4 exp-3, and these two species are unique by the pinnate caudal seta III. These species differ in the number of dorsal integumental windows on the cephalothorax (three in N. minutus, one in N. dimorphicus), shape of the distal small seta on the P4 endopod (naked in N. minutus, pinnate in N. dimorphicus), shape of the caudal seta IV (inflated and leaf-shaped in N. minutus, with a globular expansion at its insertion and slender in N. dimorphicus), and shape of the caudal seta V (anterior part cylindrical in N. minutus, inflated and bulbous in N. dimorphicus). The males of N. minutus and N. dimorphicus differ in the number of dorsal integumental windows on the cephalothorax (without any in N. minutus, with one integumental window in N. dimorphicus), number of outer spines on P2-P3 exp-3 (three in N. minutus, four in N. dimorphicus), shape of the inner seta on P3 enp-2 (naked in N. minutus, pinnate in N. dimorphicus), and shape of the outer medial and outermost setae on the P5 endopod (pinnate in N. minutus, naked in N. dimorphicus). Nannopus serratus sp. nov. and N. unisegmentatus Shen & Tai, 1964 share the presence of two setae on P2 enp-2 but differ in ornamentation and position of the setae on the mandibular palp, shape of the inner seta on P3 enp-2, and shape of distal seta on P4 enp-2. Nannopus parvus sp. nov. and N. bulbiseta sp. nov. belong to the group of species with the female P5 exopod fused, but these two species can be separated from the others by the presence of two bulbiform pinnate setae on the second segment of the antennule, as well as by the relative length and shape of the inner subdistal pectinate seta of P4 exp-3 (pectinate and 0.5 to 0.7 times as long as those in other congeners), and the shape of outer medial and outermost setae on the P5 endopod (naked only in female). However, they both display unique characters among all congeners. The caudal ramus of N. parvus is trapezoidal or square-shaped, and 0.4 to 0.5 times as long as those in other congeners, and the caudal seta V is very short and spine-like. Nannopus bulbiseta has four and five setae on P2 and P4 exp-3 respectively, the caudal ramus is sub-cylindrical or sub-rectangular, and the proximal part of the female caudal seta V is bulbous and very slender distally. A key to 14 valid species of Nannopus is provided.


Assuntos
Copépodes , Estruturas Animais , Animais , Cor , Meio Ambiente , Feminino , Masculino , República da Coreia
16.
Zookeys ; (665): 37-57, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28769625

RESUMO

Two new species of Leptopsyllus are described from the subtidal zone of Korea. Both species were assigned to the subgenus Leptopsyllus (Leptopsyllus) T. Scott, 1894, based on following three characters: two-segmented rami of P1, absence of endopod on P2 and P3, and presence of one-segmented endopod of P4. L. (L.) pundius sp. n. is most closely related to L. (L.) punctatus Mielke, 1894, however clearly distinguishable from it based on mandibular exopod with two setae, shape of P6, and caudal seta III ornamented with spinules in the new species. L. (L.) koreanus sp. n. is clearly distinguishable from its congeners by the second segment of P1 endopod armed with one element, male baseoendopod of P5 with one seta, and one segmented endopod of mandibular palp. The world distribution and updated key to the species of the genus Leptopsyllus are provided.

17.
Zookeys ; (680): 13-31, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28769714

RESUMO

A new species of Microcharon Karaman, 1934 (Asellota: Lepidocharontidae) is described from Miho-Uchihama beach, Shizuoka, Japan. Microcharon tanakaisp. n. differs from its congeners by having nine simple, five penicillate setae on antennal article 6; one simple distal seta on article 1 of the mandibular palp and having the apical lobe of male pleopod 1 convex, rounded, armed with seven setae. A key to Asian species of the genus and 16S rRNA of the new species are provided.

19.
Zookeys ; (718): 35-64, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29290714

RESUMO

Two new species of the genus Emertonia were found from the west coast of Korea. The first new species, E. koreanasp. n., is closely related to E. acutifurcata. However, the new species is clearly distinguished by the presence of two modified pinnate setae on the P5 baseoendopodal lobe. All body somites of the new species except for the last two urosomites have strongly developed hyaline frills forming quadrilateral lappets. The second new species, E. simplexsp. n., superficially resembles E. mielkei in the structure of antennary exopod (with five setae), and the shape of P5. However, this new species differs from its congener mainly by having a caudal ramus 3.5 times as long as width, and P1 enp-2 with two claw-like setae. In addition, a key to the worldwide species of Emertonia is provided.

20.
Anim Cells Syst (Seoul) ; 21(3): 217-222, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30460072

RESUMO

The rapid increase in carbon dioxide levels in seawater is causing ocean acidification and is expected to have significant effects on marine life. To explore the ability of the harpacticoid copepod Tigriopus japonicus to adapt to an increased concentration of dissolved carbon dioxide (CO2) in seawater, we compared the survival rates of adult and nauplius stages at 400, 1000, and 1550 ppm pCO2 over a 14-day period. The survival rate of T. japonicus dramatically decreased over time with increase in pCO2 concentration. At 1550 ppm, the survival rate showed a decrease of more than 20% at the end of the experimental period over that at 400 ppm. Furthermore, the survival rate decreased by a greater amount at all concentrations in nauplii than in adults, with a greater effect in wild-collected specimens than in culture-derived individuals. The results suggest that future ocean acidification may negatively influence the sustainability of T. japonicus and thus may eventually influence benthic ecosystems.

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