• Title/Summary/Keyword: Gastropod

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Evaluation of Interface Friction Characteristic using Waste Resource (불용 자원의 접촉면 마찰 특성 평가)

  • Lee, Seung-Eun;Chang, Yong-Chai;Bowders, John J.
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1456-1462
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    • 2008
  • This study conducted a direct shear test to evaluate friction properties on contact surface of waste resources including turban shell, gastropod shell and PET bottle film. The contact surface that was considered for computation of shear strength in contact surface were turban shell/turban shell, gastropod shell/gastropod shell, and PET bottle film/PET bottle film. As a result of test, friction angle was found to be $16.7^{\circ}$ for contact surface of turban shell/turban shell, $35.4^{\circ}$ for gastropod shell/gastropod shell, and about $11^{\circ}$ for PET bottle film/PET bottle film. Using the results, the author aims to provide a possibility for application of waste resource in the field.

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Heavy Metal Concentrations in the Mollusc Gastropod, Cipangopaludina chinensis malleata from Upo Wetland Reflect the Level of Heavy Metals in the Sediments

  • Kim, Heung-Tae;Kim, Jae-Geun
    • Journal of Ecology and Environment
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    • v.29 no.5
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    • pp.453-460
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    • 2006
  • Upo wetland is the largest inland wetland in Korea as Ramsar Convention Area. The purposes of the study were to investigate the levels of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the sediment and Cipangopaludina chinensis malleata from three sites of the wetland and to assess the potential of the gastropod as a bioindicator for heavy metal levels. The gastropods were dissected into shell and soft tissue without the digestive and excretive organs. The levels of Cd, Cu and Pb were below the guideline of Soil Environment Conservation Act and the heavy metals except Cr were slightly different among the sites. Cd was higher in Upo site ($0.32{\mu}g/g$) than Sajipo site ($0.28{\mu}g/g$). Cu and Zn showed the highest value in Sajipo as $43.5{\mu}g/g\;and\;39.8{\mu}g/g$, respectively while the concentrations of Pb and Zn were the highest in Upstream as $58.8{\mu}g/g\;and\;138{\mu}g/g$, respectively. In the soft tissues and shells of the gastropod, the overall common trend in the concentrations of the heavy metals was revealed with the following order: Zn > Cu > Cr > Ni > Pb > Cd and Ni > Zn > Cr > Cu > Pb > Cd, respectively. Although the soft tissues exhibited higher concentrations of the heavy metals except Ni than the shell in the gastropod, the levels of Cd and Pb in the gastropod were generally below the restrictive values set up by Korea Food & Drug Administration. From Duncan's Multiple Range Test (DMRT) results, the concentrations of Pb and Zn in the sediments among the sites were reflected on the soft tissue (Pb) and the shell (Pb and Zn) of the gastropod in the same order. The lower value of coefficient of variation (CV) in Pb concentration of the shell than in that of the soft tissue supports the usefulness of the shell as a bioindicator for Pb pollution. Although the CV value in the shell was a little higher than in the soft tissue, DMRT results and the stability of incorporated Zn into the shell support the use of the shell of the gastropod as a potential bioindicator for long-term contamination of Zn.

Three New Species of Anthessius (Copepoda, Cyclopoida, Anthessiidae) Associated with Mollusks

  • Lee, Jimin;Kim, Il-Hoi
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.3
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    • pp.187-204
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    • 2021
  • Three new copepod species of Anthessius are described as associates of mollusks. Anthessius tuberculatus n. sp. associated with the bivalve Asaphis violascens (Forsskal in Niebuhr, 1775) in Kosrae, Micronesia bears a pair of dorsal tubercles on the fifth pedigerous somite. Anthessius rarus n. sp. is associated with the aplysiid gastropod Dolabella auricularia (Lightfoot, 1786) in Bohol, the Philippines and has elongate caudal rami which are about 5.2 times as long as wide. Anthessius cucullatus n. sp. associated with the aplysiid gastropod Aplysia kurodai Baba, 1937 in Korea has a hood-like dorsal expansion on genital double-somite of the female.

Evaluation of Interface Friction Properties between Coarse Grained Materials and Geosynthetics (조립재료와 지오신세틱스의 접촉면 마찰특성 평가)

  • Chang, Yongchai;Lee, Seungeun;Seo, Jiwoong
    • Journal of the Korean GEO-environmental Society
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    • v.9 no.5
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    • pp.53-59
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    • 2008
  • The purpose of the study was to evaluate how much gastropod shell effected its properties better than crushed stone as coarse grained materials by comparing friction properties of a contact surface between coarse grained materials and geosynthetics with the large-scale direct shear test. To achieve the purpose, the study compared and analyzed friction coefficient and friction angle by making crushed stone or gastropod shell into model ground and by installing and shearing non-woven fabric or geostrip geosynthetics. As the results of the analysis, crushed stone had the internal friction angle of $33.8^{\circ}$ when its unit weight was $13.7kN/m^3$ and gastropod shell had the internal friction angle of $35.4^{\circ}$ when its unit weight was $5.4kN/m^3$. Also, the friction angle of a contact surface between geosynthetics and crushed stone was larger than the friction angle of a contact surface between geosynthetics and gastropod shell.

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Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) in the Republic of Korea and Its Surface Ultrastructure

  • Han, Eun-Taek;Park, Jeong-Hyun;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.50 no.2
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    • pp.177-180
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    • 2012
  • Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) was detected from a brackish water gastropod species (Cerithideopsilla cingulata) in a coatal area of Shinan-gun, Jeollanam-do (Province), the Republic of Korea, and its surface ultrastructure was studied using a scanning electron microscope. The cercariae were found freely swimming or enveloped within daughter sporocysts when the snail host was mechanically broken. They were morphologically characterized by a linguiform and ventrally concave body, a long and bifurcated tail, and the presence of a holdfast (=tribocytic) organ posterior to the ventral sucker. On the whole ventral and dorsal surfaces, peg-like tegumental spines were densely distributed. Around the oral sucker, several sensory papillae, each with a short cilium, were distributed, and on the tail, sensory papillae, each with an extensively long cilium, were observed. This is the first record describing a cyathocotylid cercaria from a brackish water gastropod in the Republic of Korea.

Sr and Pb Isotopic Properties in Limnetic Gastropod (Semisulcospira libertina) Shell in the Jinan, Jeonbuk Area. (하천에 서식하는 민물고동(다슬기)의 Sr, Pb 동위원소 특성)

  • Jeon Seo-Ryeong;Chung Jae-il
    • Economic and Environmental Geology
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    • v.38 no.2 s.171
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    • pp.129-134
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    • 2005
  • The $^{87}Sr/^{86}Sr$ ratios between water and biogenic material are similar in marine and lacustrine environment. Pb isotope ratios we, however, reported not to have been corresponding between the biological tissues and ambient water in aquatic system, contrary to the Sr isotope ratios. In order to explore the potential application of two isotopes as environmental tracers, we report here the isotopic compositions of strontium and lead of gastropod shell in fresh water in Jinan area. The $^{87}Sr/^{86}Sr$ ratios of carbonate shells of gastropod living in fresh stream water, are similar as that of ambient water but are different by sites. The different $^{87}Sr/^{86}Sr$ ratios of stream water between the sites is likely caused by the difference of the isotopic composition of Sr derived form rocks in the basin. In contrast, there is a distinct difference of the lead isotopic values between the water and the gastropod shell, suggesting that shell-fish available lead in aquatic system is different from dissolved lead in water. It is assumed that the majority of Pb in stream water is derived from atmospheric Pb accumulated on soil materials over years rather than from rock.

Development of Assistive Mobility Equipment Modeled on Pedal Crawling Locomotion of Terrestrial Gastropod

  • Morikawa, Hirohisa;Fujihara, Ryousen;Fukaya, Yuhya;Kobayashi, Shunichi;Sakai, Hiroshi
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.79-80
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    • 2003
  • In order to develop an indoor assistive mobility equipment, we paid attention to the mechanism of locomotion in a snail, or a terrestrial gastropod molluscs. It is known that the snail moves by propagation of a pedal wave generating on a pedal surface of the snail and a pedal locomotion has flexibility far ground condition. An air mattress with a function of a pedal-like locomotion mechanism was developed and the performance of the pedal locomotory air mattress as mobility equipment was discussed.

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TEM Observations of Chemosynthetic Bacteria in the Deep-sea Hydrothermal Vents and Seep Organisms

  • Kim, Dong-Sung;Ohta, Suguru
    • Ocean and Polar Research
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    • v.24 no.3
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    • pp.215-223
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    • 2002
  • Symbiosis of chemoautrophic bacteria with the members of hydrothermal vent and cold seep communities in the deep-sea were examined by histology using transmission electron microscopy; Bathymodiolus spp. from Sagami Bay, the Iheya Ridge and the North Fiji Basin; and Ifremeria nautilei from the North Fiji Basin. Two species of Bathymodiolus, each from Sagami Bay and the Iheya Ridge harbored methane-oxidizing symbionts within their gill tissues. Vent gastropod Ifremeria nautilei from the hydrothermal vents of the North Fiji Basin housed two types of symbionts; one sulfur-oxidizing type and the other methane-oxidizing type. The occurrence of chemosynthetic symbionts in these organisms were expected before-hand based on the ecological observations of their habit. The other members of these groups from world oceans and the recent advances in the symbiosis of the vent and seep communities were reviewed.

Eggs and Egg Capsules of Three Stenoglossan Gastropod Species, Ceratostoma rorifluum, Ocinebrellus inornatum & Neptunnea constricta, (Mollusca: Neogatropoda) in the Korean Waters

  • Son, Min-Ho;Hong, Sung-Yun
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.531-532
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    • 2000
  • The morphology of molluscan egg capsule is generally regarded as being species specific (Turner, 1992), and form and structure of the egg capsule reflect the degree of anatomical complexity of the reproductive organs (Fretter & Hian, 1984). Ceratostoma rorifluum and Ocinebrellus inornatum are common and widespread muricid species found throughout the Korean rocky and boulder shores, and Neptunnea constricta is found frequently from continental shelf of the eastern sea of Korea. In spite of their predominance along the Korean coasts, morphology of their eggs and egg capsules is unknown so far. The purpose of the present study, therefore, is to provide descriptions and illustrations for identifying egg capsules of the foregoing 3 stenoglossan gastropod species. (omitted)

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