• Animal cells and systems
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• v.8 no.4
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• pp.267-280
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• 2004

Three new species of Collocheres are described as associates of crinoid and ophiuroid echinoderms from Cheju Island, Korea: Collocheres brevipes n. sp. from the crinoids Comanthus solaster A. H. Clark and Decametra tigrina (A. H. Clark); C. solidus n. sp. from two species of the crinoids Comanthus solaster and Comanthus japonicus (Muller) and one species of ophiuroid-Ophiomastax mixta (Lutken); and C. tamladus n. sp. from the crinoid Catoptometra rubroflava (A. H. Clack). The three species are distinguished from one another and other congeners by the body size, dimension of caudal ramus and free segment of leg 5, and shape and ornamentation of urosome.

• Animal Systematics, Evolution and Diversity
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• v.19 no.1
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• pp.103-109
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• 2003

Presynaptiphilus poraminutus is described as a new species in association with the ophiuroid Ampioplus ancistrotus (H. L. Clark) collected from an intertidal sand beach in the Yellow Sea. The new species is closely related to P. minutus in having the identical leg structure, but may be differentiated from the latter by the larger body, the longer genital double-somite and caudal rami, and the shorter pre-anal semite.

• Animal Systematics, Evolution and Diversity
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• v.30 no.2
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• pp.108-118
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• 2014

Micronesia is an island nation located north of Papua New Guinea in the Pacific Ocean. A survey was conducted on Chuuk, which is one of the four main islands of Micronesia, from 11-25 Nov 2012. Echinoderms collected at one intertidal area as well as at 16 SCUBA diving points of 10-40 m depths in the subtidal zone were identified based on morphological characteristics. In total, 35 species from 165 individuals were identified: two crinoids, eight asteroids, four ophiuroids, seven echinoids, and 14 holothuroids. Among them, one asteroid, one ophiuroid, one echinoid, and two holothuroids were newly recorded from Micronesia.

• Journal of Species Research
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• v.9 no.3
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• pp.273-279
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• 2020

We describe a newly recorded brittle star to South Korea, Amphiura (Amphiura) digitula (H.L. Clark, 1911), that was collected from Geoje Island, at a depth of 47 m. The species is characterized by a small disk, covered by numerous fine scales, small radial shields that are wider than long, a small stumpy hook at the distal end of the radial shield, two tooth papilla, two adoral shield spines, 2nd adoral shield spine longer than other, tapered dramatically toward dull tip, five arms with four proximal arm spines, and two tentacle scales. We also obtained a 657 bp sequence from COI gene and the amplified sequence matched the general DNA barcoding region. The NJ and ML phylogenetic analyses revealed A. (A.) digitula as monophyletic in the Amphiura clade. This species is clearly distinguished from other Amphiura species by morphological characteristics and the mitochondrial COI sequence, and thus represents the sixth Amphiura species reported to occur in Korea.

• Animal Systematics, Evolution and Diversity
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• no.nspc5
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• pp.47-60
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• 2005

The joint faunal survey of Jindo Island, Korea was performed by the Korean Society of Systematic Zoology during June 29-July 1, 2004 in commemoration of the 20th anniversary. In this study, 20 echinoderm species of 13 families, ten orders in four classes such as one crinoid species, seven asteroid species of four families in three orders, five ophiuroid species of three families in two orders, four echinoid species of two families in one order, and three holothuroid species of three families in three orders collected from six localities (Bealpo, Chopyung, Supum, Hoedong, Seomang, and $34^{\circ}11'N\;and\;126^{\circ}21'E)$ were identified. Of these, one crinoid (Antedon serrata), two asteroids (Solaster dawsoni and Distolasterias nipon) and one pohiudoid (Astrodendrum sagaminum) are newly added to the echinoderm fauna of Jindo Island and one holothudoid (Pseudocnus sp.) is newly recorded in Korean waters. The total 31 species are presently listed with some brief remarks and their distribution patterns are discussed based on the composition of geographical distribution forms.

• Ocean and Polar Research
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• v.41 no.2
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• pp.47-61
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• 2019

The Dokdo coast is known for its high biodiversity. However, few studies have examined the biodiversity and macrobenthic community on the subtidal soft-bottom. Therefore, we collected macrobenthos (> 1 mm) using a Smith-McIntyre grab ($0.1m^2$) at 15 stations along the Dokdo coast in September 2016. The sediments consisted of badly sorted (1.7) coarse sand with gravel and the mean sediment grain size was $-0.4{\phi}$. In total, 177 macrobenthic species were collected; their mean density was $1,566ind./m^2$. The number of species and density of macrobenthic fauna decreased significantly with the mean grain size. The dominant species were the amphipods Melita denticulata (16.5%) and Melita shimizui (5.5%), polychaete Salvatoria clavata (5.4%), bivalve Glycymeris aspersa (4.4%), and ophiuroid Ophionereis dubia (4.3%). The dominant macrobenthos species on the subtidal soft-bottom differed from the coastal areas of the East Sea, suggesting that the difference in the sediment grain size affected the macrobenthos. Cluster analysis was performed to divide the study area into four groups, and environmental factors which correlated with species composition and distribution in the study area were the combination of the four parameters of salinity, dissolved oxygen, total organic carbon and depth. A future seasonal investigation is needed to understand the species composition and characteristics of the Dokdo macrobenthos.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.326-344
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• 2011

Although anthropogenic disturbance of 20 years duration affects benthic habitats, few studies have examined its effects on the macrobenthic communities of a bay. The aim of this study was to determine the influence of environmental variables on the macrobenthic communities after the construction of the Hwaong dike. Macrobenthos were collected at 22 sites using a Smith McIntyre grab (0.1 $m^2$) in August 2007 and February 2008. Total organic content was very low around the Hwaong dike. Sediment grain size increased from the Hwaong dike to the outer bay. In total, 317 species of macrobenthic fauna were collected and the mean density was 1,155 ind. $m^{-2}$, both of which were higher than the results of previous studies. The dominant species, $Hetermastus$ $filiformis$, known to be a potential pollution indicator, was more abundant near the Hwaong dike. Conversely, species sensitive to organic pollution, such as the polychaete $Ampharete$ $arctica$ and the ophiuroid $Amphioplus$ $squamata$, exhibited higher mean densities in areas distant from the dike. A cluster analysis indicated that the macrobenthic community was divided into two distinct groups: group I near the dike and group II in the outer bay, which were affected by sediment grain size and total organic content. This study suggests that variations in sediment grain size and organic content after dike construction are important factors controlling the macrobenthic community in Asan Bay.

• Economic and Environmental Geology
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• v.42 no.4
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• pp.367-376
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• 2009

Forty specimens of fossil ophiuroids were collected from two formations of the Cenozoic marine deposits, Duho Formation and Hagjeon Formation, Pohang Basin, Korea. A few specimens were three-dimensionally preserved: most of them were remained flattened and articulated. Although a gross morphology is well preserved in some specimens, the details such as disk shape and plates which is the most important diagnostic features were not observed. Most of the arms are disarticulated, and thus arm vertebra, arm spines and/or arm plates are separately preserved. Only an oral side is recognized in an attached specimens because crossing arms into disk are clearly visible. It is, thus almost impossible to identify Korean ophiuroid fossils as a species level or even a genus level. The fossils were classified into 3 groups by gross morphology of disk and arm, and architecture of vertebra. The most abundant fossils (32 specimens), were found only in the Hagjeon Formation. The majority of specimens are partially disarticulated, having only proximal and median portions of their arms preserved. Arm plates are disarticulated from arm vertebra: most of them show structure of arm vertebra. It has long and well-preserved arm spines, and large tentacle pore. Some specimens (4 specimens) from the Duho Formation is characterized by short and conical arm spines, and well-developed arm plates. Lateral arm plates are small in compared to dorsal and ventral arm plates. The others (4 specimens) is poor in preservation state showing circular oral disk and relatively short sinuous arms. No arm plates are either identified.