• Economic and Environmental Geology
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• v.45 no.3
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• pp.317-333
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• 2012

The Yeongweol Group is a Lower Paleozoic mixed carbonate-siliciclastic sequence in the Taebaeksan Basin of Korea, and consists of five lithologic formations: Sambangsan, Machari, Wagok, Mungok, and Yeongheung in ascending order. Sequence stratigraphic interpretation of the group indicates that initial flooding in the Yeongweol area of the Taebaeksan Basin resulted in basal siliciclastic-dominated sequences of the Sambangsan Formation during the Middle Cambrian. The accelerated sea-level rise in the late Middle to early Late Cambrian generated a mixed carbonate-siliciclastic slope or deep ramp sequence of shale, grainstone and breccia intercalations, representing the lower part of the Machari Formation. The continued rise of sea level in the Late Cambrian made substantial accommodation space and activated subtidal carbonate factory, forming carbonate-dominated subtidal platform sequence in the middle and upper parts of the Machari Formation. The overlying Wagok Formation might originally be a ramp carbonate sequence of subtidal ribbon carbonates and marls with conglomerates, deposited during the normal rise of relative sea level in the late Late Cambrian. The formation was affected by unstable dolomitization shortly after the deposition during the relative sea-level fall in the latest Cambrian or earliest Ordovician. Subsequently, it was extensively dolomitized under the deep burial diagenetic condition. During the Early Ordovician (Tremadocian), global transgression (viz. Sauk) was continued, and subtidal ramp deposition was sustained in the Yeongweol platform, forming the Mungok Formation. The formation is overlain by the peritidal carbonates of the Yeongheung Formation, and is stacked by cyclic sedimentation during the Early to Middle Ordovician (Arenigian to Caradocian). The lithologic change from subtidal ramp to peritidal facies is preserved at the uppermost part of the Mungok Formation. The transition between Sauk and Tippecanoe sequences is recognized within the middle part of the Yeongheung Formation as a minimum accommodation zone. The global eustatic fall in the earliest Middle Ordovician and the ensuing rise of relative sea level during the Darrwillian to Caradocian produced broadly-prograding peritidal carbonates of shallowing-upward cyclic successions within the Yeongheung Formation. The reconstructed relative sea-level curve of the Yeongweol platform is very similar to that of the Taebaek platform. This reveals that the Yeongweol platform experienced same tectonic movements with the Taebaek platform, and consequently that both platform sequences might be located in a body or somewhere separately in the margin of the North China platform. The significant differences in lithologic and stratigraphic successions imply that the Yeongweol platform was much far from the Taebaek platform and not associated with the Taebaek platform as a single depositional system. The Yeongweol platform was probably located in relatively open shallow marine environments, whereas the Taebaek platform was a part of the restricted embayments. During the late Paleozoic to early Mesozoic amalgamations of the Korean massifs, the Yeongweol platform was probably pushed against the Taebaek platform by the complex movement, forming fragmented platform sequences of the Taebaeksan Basin.

• Animal cells and systems
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• v.6 no.3
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• pp.201-206
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• 2002

Three halacarid species belonging to the genus Copidognathus are recorded from the shallow subtidal sands at Ko Taenae Islet (sand dune) off Ko Pha-Ngan Island, Thailand: Copidognathus thailandicus n. sp., C. euryalus Bartsch, 1997 and C. orarius Otto, 2001. Copidognathus thailandicus n. sp. comes close with C. cribrosoma (Police, 1909) and C. cribellus Bartsch, 1993 due to dorsal plates completely covered with rosette pores. Dissimilarities among them are discussed. Copidognathus euryalus and C. orarius are recorded hove for the first time from Thailand and away from its type locality. The present paper is also the first contribution on the taxonomy of Halacaridae (Acari) from Thailand.

• Animal cells and systems
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• v.8 no.3
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• pp.155-163
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• 2004

Tenuidraconema koreensis, a new species of free-living marine nematodes, collected from the subtidal coarse sediments and various invertebrates of Namae, is described. The new species differs from T. fiersi Decraemer, 1989, the only other species in the genus, by having the combination of the following characters: the position of twelve cephalic adhesion tubes in both sexes (anterior six cephalic adhesion tubes inserted on the rostrum and posterior six inserted on the body annules), and the number of posterior sublateral adhesion tubes (12 in male and 13 in female) and posterior subventral adhesion tubes (15 in male and 19 in female). This paper contains the description of the new species with illustrations and scanning electron microscope (SEM) photomicrographs. This is the first discovery of the monotypic genus Tenuidraconema outside the type locality.

• The Korean Journal of Malacology
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• v.11 no.1
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• pp.35-50
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• 1995

저자들은 1994년 7월부터 1995년 2월까지 남해안 마산만의 덕동 지역과 대주군인 자란도 및 이수도에서 오염원의 영향을 민감하게 받는 종을 선별하기 위하여 조간대 및 아조대의 저서동물 군집을 채집하고 정성, 정량적 분석을 실시하였다. 조사결과 덕동 지역 군집은 대조군인 자란도나 이수도에 비하여 구성 종 수가 현저히 적었고 다양도지수 및 균등도가 낮았으며 그 다음은 자란도와 이수도순이었다. 우점도는 덕동이 가장 높았고 자란도, 이수도순이었다. 또한 조사지역 내에서 연체류중 패각만 채집된 종수가 덕동에서 19종, 자란도 3종, 이수도 4종으로 중복된 것을 제외하면 총 25종이 되며 이들 또한 오염과 관계 있을 것으로 예견된다.

• Animal Systematics, Evolution and Diversity
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• v.29 no.1
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• pp.1-17
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• 2013

Micronesia is an island nation located north of Papua New Guinea in the Pacific Ocean. A survey was executed on Kosrae, which is one of the four main islands of Micronesia, during January 23-30, 2011 and January 8-15, 2012. The echinoderms were collected at eight intertidal areas and at 12 SCUBA diving points at depths of 10-50 m in the subtidal zone. They were identified based on morphological characteristics. In total, 50 species from 276 individuals were identified: three crinoids, 11 asteroids, seven ophiuroids, 10 echinoids, and 19 holothuroids. Among them, two crinoids, five asteroids, three ophiuroids, four echinoids and two holothuroids were newly recorded from Kosrae.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.663-671
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• 2015

We report the first finding of Halarachnion parvum and Champia lubrica from Korea based on morphology and the plastid rbcL sequence analyses. H. parvum occurs in the subtidal zone of Munseom, the southern part of Jeju. Thalli have short stipe, and elliptical to ovate fronds with marginal proliferations of up to 3 cm in height. H. parvum has zonately divided tetrasporangia and cystocarp immersed under the cortical layer. Champia lubrica appears in Namhae, Gyeongnam and Seopseom, Jeju. Thalli are erect, irregularly branched, terete, obtuse apex, up to 3-5 cm high, and have tetrahedrally divided tetrasporangia. Molecular analyses of the plastid rbcL gene reveal that two species are clearly separated from other species of their respective genera. H. parvum is sister with Halarachnion latissimum in 3.1-3.2% sequence divergence, and C. lubrica is closely related to the sample from Japan with 0.2% sequence divergence.

• The Korean Journal of Malacology
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• v.29 no.4
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• pp.343-376
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• 2013

The Federated States of Micronesia consists of four states of Yap, Chuuk, Pohnpei and Kosrae, which are located in the West Pacific Ocean. In order to investigate molluscan fauna of Kosrae Island, field survey was made twice from 21st to 30th of January, 2011 and from 6th to 17th of January, 2012 for four localities including 10 intertidal and 14 subtidal zones of Kosrae Island. The mollusk samples collected were identified based on their morphological characteristics, comprising a total of 120 species from 30 families through this survey. In this study, we provided species list and illustrations for 120 species identified, and combined these with the previous record, resulting in a total of 208 species from 47 families in Kosrae Island.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.319-328
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• 2017

The continuous exploration in deep seawater from Korea makes us lead the discovery of ancient Chlorophyta, Palmophyllum, in the Korean coast. The phylogenetic analyses of 18S rRNA and rbcL genes demonstrate that our specimens are Palmophyllum crassum (Naccari) Rabenhorst, recorded in Japan and clearly distinguished from P. umbracola from New Zealand and California, USA. Palmophyllum crassum grows in the subtidal region, 8-30 m deep, and has a crustose thallus which is closely adherent to substrates such as non-geniculate crustose coralline algae, sponge, shells, or rocks. P. crassum is composed of numerous spherical cells embedded in the gelatinous matrix. The discovery of this ancient green seaweed implies that the Korean coast is one of the hotspots of algal species diversity and has the suitable marine environment for algal speciation. We suggest the grounds to conserve the Korean coast environmentally as the biodiversity center of marine species by studying the phylogeny of seaweeds.

• ALGAE
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• v.28 no.1
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• pp.53-62
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• 2013

Actinotrichia is a calcified galaxauracean red algal genus with temperate and tropical distributions in the Indian and Pacific Oceans. Morphological characteristics, along with rbcL and cox1 sequences, were analyzed from specimens collected in the western Pacific and the Indian Oceans. Both rbcL and cox1 data confirmed the occurrence of A. fragilis, A. robusta, and Actinotrichia sp. in this region. The presence of A. fragilis was verified in tropical Indo-Pacific and temperate northeast Asian waters and was characterized by high genetic diversity. Although A. robusta commonly occurs in the East China Sea, we confirmed its presence on rocks and crustose algae in the subtidal zone of three islands in the Andaman Sea. Actinotrichia sp. was similar to A. calcea in morphology and distribution, but with sufficiently different sequences, thus, additional sampling over the range will enable a more realistic evaluation of its taxonomic status.

• Animal Systematics, Evolution and Diversity
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• v.31 no.3
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• pp.146-152
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• 2015

Two scleractinian species are newly recorded in Korea: Leptoseris mycetoseroides Wells, 1954 and Phyllangia hayamaensis (Eguchi, 1968). The two genera Leptoseris Milne Edwards and Haime, 1849 and Phyllangia Milne Edwards and Haime, 1848 are also newly recorded in Korea. The specimens were collected from the subtidal zones of Jeju-do Island, Korea by SCUBA diving from 1991 to 2007. Leptoseris mycetoseroides is characterized by its platelike growth form, intratentacular budding, irregularly developed collines, single styliform columella, and even septa and septocostae. Phyllangia hayamaensis is distinguished by its encrusting and plocoid growth form of corallites basally united with common coenosteum, trabecular columella, and irregular septal arrangements and paliform lobes.