• 제목/요약/키워드: Dokdo

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A New Cyclopinid Species of the Rarely Known Genus Cyclopinopsis (Copepoda, Cyclopinidae) from Korea

  • Lee, Jimin;Chang, Cheon Young
    • Animal Systematics, Evolution and Diversity
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    • 제35권3호
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    • pp.114-122
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    • 2019
  • A new species belonging to the genus Cyclopinopsis Smirnov, 1935 (Cyclopinidae) is described from Korea, as the third species of the genus. Specimens were collected by washing the subtidal sediments off Dokdo Island in the East Sea and the intertidal sands at Baegripo beach, Taean Peninsula on the Yellow Sea coast. Cyclopinopsis deformata n. sp. is characteristic and distinguished from its two congeneric species currently recognized, C. curticauda Smirnov, 1935 and C. brasiliensis Herbst, 1955 in having a deformed seta at the outer distal corner of the third exopodal segment of leg 4. The seta is supposed to be deformed from an outer spine on the third exopodal segment of leg 4, which has been known as completely lost in the genus until now. A character comparison table of the three species and a key to species of the genus Cyclopinopsis are provided herein.

Redescriptions of Euplotes encysticus and E. rariseta (Protist: Ciliophora: Euplotida)

  • Kim, Eun-Hee;Lee, Won Je
    • Journal of Species Research
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    • 제8권1호
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    • pp.128-135
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    • 2019
  • Two euplotid ciliates, Euplotes encysticus Yonezawa, 1985 and E. rariseta Curds et al., 1974, were isolated from a freshwater pond called Mulgol in Dokdo of the East Sea and from Masan Bay/Jeju Island, Korea, respectively. Both species are redescribed based on live observations and protargol impregnation. Cells of Euplotes encysticus are asymmetrically oval, $63-79{\times}41-61{\mu}m$ in vivo and capable of encystment. The cells have 31-36 adoral zone of membranelles(AZM), 9 fronto-ventral cirri (FVC), 5 transverse cirri (TC), 2-3 caudal cirri (CC), 2 marginal cirri (MC), 7 dorsal kineties (DK), and 19-22 dorsal cilia in middle DK. The cells of Euplotes rariseta has a small ovoid form and are $32-44{\times}23-35{\mu}m$ in vivo, 18-22 AZM, 10 FVC, 5 TC, 2 CC, 1 MC and 6 DK.

First Record of Two Hyperiid Amphipods, Phronima atlantica and Oxycephalus clausi, from Dokdo, Korea

  • Shin, Myung-Hwa;Lim, Byung-Jin
    • Animal Systematics, Evolution and Diversity
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    • 제36권4호
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    • pp.408-415
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    • 2020
  • The suborder Hyperiidea is an abundant crustacean zooplankton in pelagic communities with copepods and euphausiaceans. Hyperiidean amphipods are known to be commensals or parasites of gelatinous organisms such as medusae, siphonophores, ctenophores, and salps. Korean hyperiid amphipods have not received taxonomical attention since the 1970s. During a survey of pelagic crustacean species, two species of hyperiid amphipods, Phronima atlantica Guérin-Méneville, 1836 belonging to the family Phronimidae and Oxycephalus clausi Bovallius, 1887 belonging to the family Oxycephalidae, were found on Dokdo, East Sea, Korea. These two species are new to Korean waters. In the present study, we provide descriptions and illustrations of these two hyperiid species.

A New Species of Antennella (Hydrozoa: Leptothecata: Halopterididae) from Korea

  • Hyo-Jin Yu;Seung-Joon Lee;Sung-Jin Hwang
    • Animal Systematics, Evolution and Diversity
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    • 제40권1호
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    • pp.79-87
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    • 2024
  • A taxonomic examination of hydroids collected from the subtidal zones of Ulleungdo and Dokdo located in the East Sea of Korea from 2017 to 2023 was conducted. Through this study, Antennella aurantia n. sp., a new species belonging to the family Halopterididae, was newly added to the hydrozoan fauna of Korea. This new species is clearly distinguished from similar species by the different morphology and size of the hydrothecae, lateral nematothecae, and gonothecae. By comparing the 16S rRNA sequence with 7 recorded species within the Antennella, the interspecific genetic distance to the new species was 8.2-28.9%, which is very high compared to the intraspecific variation of 0.0%, showing that it was clearly distinguished from other species. As a result of this study, a total of 4 Antennella species are reported in the hydrozoan fauna of Korea.

올해의 씰-2006 크리스마스 씰 I ♥ Dokdo

  • 대한결핵협회
    • 보건세계
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    • 제53권10호통권602호
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    • pp.22-23
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    • 2006
  • "독도"를 주제로 한 이번 씰은 일반인을 대상으로 주제 및 도안을 공모하여 뽑힌 한진아 씨의 작품으로 10월 2일부터 전국 우체국에서 구입할 수 있다.(10매 1시트 3,000원)

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진주배말(Cellana grata)의 수정 및 후기 피면자 유생의 착저단계에 미치는 저염분 영향 (Low Salinity Effects on the Fertilization and Settlement of Post Veliger Larvae in the Limpet Cellana grata)

  • 윤성진;정주학;김윤배
    • Ocean and Polar Research
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    • 제37권1호
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    • pp.37-47
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    • 2015
  • The effects of low salinity (fertilization success and larval survival) on the limpet Cellana grata were studied at early stages of development using the marine bioassay technique. It was shown that, under normal conditions for development from fertilization to the post veliger stage, the salinity must be not less than 20.0~35.0 psu. However, the fertilization rate and larval survival of C. grata was obviously reduced at 5.0 psu and 10.0 psu, respectively. Mass mortality was estimated to occur at <20.0 psu (48-h $EC_{50}=19.54psu$) and the survival rate of normal veliger larvae decreased with experimental time during exposure. No observed effective concentration (NOEC) and lowest observed effect concentration (LOEC) of post veliger were estimated at 30.0 psu and 25.0 psu, respectively, during 48-h exposure. The tolerance limits of the test species to salinity revealed various concentration ranges of salinity, which may reflect the physiology and ecology of the initial development stages of C. grata. These results demonstrate that reduced salinity is detrimental to the reproductive success and larval survival of C. grata, and if salinity is lowered by natural or anthropogenic sources during spawning, this would lead to decreased reproductive success and larval settlement.

First record of a marine microalgal species, Chlorella gloriosa (Trebouxiophyceae) isolated from the Dokdo Islands, Korea

  • Kang, Nam Seon;Lee, Jung A;Jang, Hyeong Seok;Kim, Kyeong Mi;Kim, Eun Song;Yoon, Moongeun;Hong, Ji Won
    • 환경생물
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    • 제37권4호
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    • pp.526-534
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    • 2019
  • Chlorella gloriosa (Chlorellaceae, Trebouxiophyceae) was isolated from seawater off the coast of the Dokdo Islands in Korea. An axenic culture was established using the streak-plate method on f/2 agar media supplemented with antibiotics, allowing identification of the isolate by morphological, molecular, and physiological analyses. The morphological characteristics observed by light and electron microscopy revealed typical morphologies of C. gloriosa species. The molecular phylogenetic inference drawn from the small-subunit 18S rRNA sequence verified that the microalgal strain belongs to C. gloriosa. Additionally, gas chromatography-mass spectrometry analysis showed that the isolate was rich in nutritionally important omega-3 and -6 polyunsaturated fatty acids and high-performance liquid chromatography analysis revealed that the high-value antioxidants lutein and violaxanthin were biosynthesized as accessory pigments by this microalga, with arabinose, galactose, and glucose as the major monosaccharides. Therefore, in this study, a Korean marine C. gloriosa species was discovered, characterized, and described, and subsequently added to the national culture collection.

독도 인근 해저퇴적물과 유기 퇴적물 분포 특성 (Characterization of Clastic and Organic Sediments Near Dokdo, Korea)

  • 전창표;김창환;이성주
    • 한국광물학회지
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    • 제26권2호
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    • pp.65-80
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    • 2013
  • 독도로부터의 거리 및 수심에 따라 채취된 표층 퇴적물에 대하여 입도분석, 광물분석, 유기물 분석 및 미화석 분석 결과를 이용하여 독도 인근 해저의 퇴적 기작 및 유기 퇴적물의 분포를 규명하였다. 독도 인근 해저 퇴적물은 자갈 및 사질이 우세하며, 끌림에 의한 퇴적 작용이 주를 이루는 반면에 독도와 거리가 멀어짐에 따라 실트와 머드의 비율이 증가하며 점토광물과 장석 등의 광물 성분의 변화를 보이고 뜬짐에 의한 퇴적이 우세해지는 경향을 보인다. 퇴적물에 포함된 유기 퇴적물의 군집 조성 또한 큰 변화를 보이는데, 연안 퇴적물에서는 해양 기원의 유기 퇴적물이, 심해 퇴적물에서는 육상 기원의 유기 퇴적물이 우점한다. 이러한 유기 퇴적물의 군집 변화는 퇴적물의 입도에 큰 영향을 받는 것으로 밝혀졌으며 유기 퇴적물중 높은 화분 농집도는 심해 퇴적물의 유기탄소 함량을 증가시키는데 중요한 역할을 하는 것으로 판단된다.

Genetical identification and morphological description of the larvae and juveniles of Porocottus leptosomus (Pisces: Cottidae) from Korea

  • Shin, Ui Cheol;Jeong, Yeon Kyu;Yoon, Sang Chul;Choi, Kwang Ho;Kim, Jin-Koo
    • Fisheries and Aquatic Sciences
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    • 제21권12호
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    • pp.37.1-37.10
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    • 2018
  • The larvae and juveniles of Porocottus leptosomus belonging to the family Cottidae were collected (n = 95, 3.9-16.5 mm in body length, BL) from Busan, Korea, in March 2015. The larvae and juvenile were identified using DNA barcoding as P. leptosomus, and their morphological description was presented in detail. The yolk-sac larvae (3.9-5.6 mm BL) body was slightly compressed, the head was large, the eye was round and large, and the anus was before the middle of the body. The preflexion larvae (5.2-10.0 mm BL) body length drastically increased; caudal fin rays began to occur. The flexion larvae (9.4-11.8 mm BL) notochord flexion started; dorsal, pectoral, and anal fin rays began to occur; pelvic fin buds are seen; they possessed a pair of parietal spine; and a pair of supraocular cirri was first to develop. At 12 mm BL, the notochord was completely flexed. The larva stage (3.9-12.6 mm SL) had the stellate melanophores in the head, isthmus, gut, and tail (along to the ventral midline). During the juvenile stage (11.4-16.5 mm BL), melanophores covered the head and began to form five black bands on the side of the body. The larvae of P. leptosomus spent pelagic life, but moved to the bottom during the juvenile stage. The larvae and juveniles of P. leptosomus differ from other cottid larval fishes by body shape, melanophore head pattern, and spine development. P. leptosomus can be distinguished from Porocottus allisi by morphological development and the occurrence of larval fish: preopercular spine development, melanophore pattern, and caudal fin development.