• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.265-281
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• 1992

The materials of this study consist of both specimens and survey records of the mollusks and crustaceans which were obtained from 30 collection sites in the Naktong Estuary during Aug.-Nov., 1991. The mollusks and crustaceans collected and identified in this study are 31 and 50 species, respectively. Of these two species of mollusks and six species of crustaceans were newly recored in this area. Including the previous records, the occurrence and distribution of 63 molluscan species and 138 crustacean species were compared in eight zones, before and after the construction of the Naktong Estuary Barrage. During this investigation, only a few species of mollusks occurred in the northern freshwaters off the Barrage. The habitats for the intertidal species were greatly destructed along the eastern part of the UIsuk Is. and the riverside of Tadaep'o where the bank was recently constructed. The commercial bivalves including Corbicula fluminea and Ruditapes Philkippinarum were greatly decreased in number in all the eatuarine waters. A freshwater crab, Eriocheir japonicus, seems to be extinguished in the Naktong River and its neighbouring streams.

• Proceedings of the Korean Quaternary Association Conference
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• 2002.06a
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• pp.9-9
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• 2002

• ALGAE
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• v.25 no.4
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• pp.217-227
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• 2010

During feeding on algal cytoplasm, some sacoglossans are known to keep the chloroplasts photosynthetically active for days to months in their digestive cells. Korean sacoglossan mollusks containing functional chloroplasts were screened using an in vivo chlorophyll fluorescence measuring system (pulse amplitude modulation, PAM). We collected six sacoglossans feeding on siphonous and siphonocladous green algae (Elysia atroviridis, E. nigrocapitata, E. ornata, Ercolania boodleae, Placida dendritica, Stiliger sp.) and one feeding on ceramiaceaen algae (Stiliger berghi) and performed feeding experiments using 37 algal species. Three species of Elysia showed strong photosynthetic activity for months. However, P. dendritica maintained functional chloroplasts only for several hours after feeding. E. boodleae, S. berghi, and Stiliger sp. showed no photosynthetic activity in any circumstances. Among all species, E. nigrocapitata was capable to tolerate the longest period of starvation for over 4 months. Four 'solar powered' sacoglossans bonded avidly to their specific algal food. Each species attached to and consumed only one algal species when several algae were given together. While they occasionally consumed other algae after prolonged starvation, they always reverted to their specific algae when available.

• 대한상한금궤의학회지
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• v.11 no.1
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• pp.1-9
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• 2019

Objective : The purpose of this study was to analyze the origin of Meretrix. Method : Bibliographies about Meretrix were examined focusing on the origin. Based on this analysis, the list and characteristics of the origin-mineral were presented. Results : Based on the Meretrix, the Korean and foreign literature were investigated to make a list, and the process of changing the origin was organized in chronological order. Based on these results, the shape of the currently cultivated or distributed drugs, the status of the distributed drugs and the status of the distributed products were summarized. In addition, the results of summarizing the adverse effects and sensitivities of the efficacy and prestige are as follows: 1. The origin of the Meretrix corresponded to the fall of the mollusks Merethrix metrix L. and Cyclina sinensis Gmelin, which are mollusks belonging to the reference family Veneridae. Their Herbal name is CONCHA CYCLINAE SEU MERETRICIS and they have therapeutic effects on cough, asthma, thirsty and chest heavies. 2. Munhap (文蛤) is a different name of GALLA CHINENSIS. It has therapeutic effects on various skin diseases. Conclusions : The Meretrix means two herbs. The first one is CONCHA CYCLINAE SEU MERETRICIS, the other is GALLA CHINENSIS. They should be used separately according to their clinical use.

• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.1-9
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• 2013

In this study, we tried to describe the distribution patterns of marine opportunistic mollusks in Korean waters where various environmental stresses have been imposed. Five opportunistic molluscan species were found from four types of disturbed benthic environments around Korea. Theora fragilis, Macoma incongrua, Musculista senhousia were typical dominant species mainly in the coastal area such as harbour regions and semi-enclosed regions where their sediments were enriched with organic matter and summer hypoxia occurred. However, in the waste dumping areas located in the Yellow Sea and southeastern shelf, small size bivalves such as Thyasira tokunagai and Raetellops pulchella were typical opportunistic species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.104-115
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• 2015

This study was conducted during April-June in 2008 and 2010, following the Taean Oil Spill. We measured year-to-year changes in benthos species abundances and composition in 16 intertidal zone regions of Chungcheongnam-do. In total, 154 species were found 2008 and 134 in 2010; the mean abundance per area was $403ind./m^2$ and $242ind./m^2$, respectively. In 2008, the 10 dominant species included four species of arthropods, three species of annelids, and three species of mollusks. In 2010, dominant species included five species of annelids, three species of mollusks, one species of arthropods, and one other species. We used bray-curtis similarity to group species and found two groups in 2008 and five in 2010, complementing our NMDS analysis. Finally, we tested correlations between abiotic and biotic factors, and implemented a BIO-ENV analysis, which showed that sediment type, MZ (Phi), and organic content are important environmental factors affecting benthos in the Chung-nam tidal flats.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.65-104
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• 2007

This catalogue is the result of a four-year survey of the mollusks of Jeju Island, the southernmost island in the Republic of Korea. Forty-eight survey stations were visited, with a total of 82 specific localities being sampled. Literature records were also obtained. Local and world distribution of each species is included. This survey reports a total of 1,072 mollusk species and subspecies; 1,015 marine and 57 land and freshwater. There are 812 gastropods, of which 755 are either entirely marine or have marine affinities. The best represented of the marine families are the Pyramidellidae, Trochidae, and Ovulidae. There are 225 bivalves, none being freshwater species, with the Veneridae, Mytilidae, and Arcidae having the largest number of species. Among the smaller classes there are sixteen Cephalopoda, eleven Polyplacophora, and eight Scaphopoda. Compared to mainland Korea, Jeju Island has a rather small terrestrial mollusk fauna and a depauperate freshwater one, with mainly Palearctic connections. The Helixarionidae and Bradybaenidae are the largest terrestrial families. The marine faunal affinities with the neighboring Japonic and Indo-West Pacific provinces are also discussed, revealing that this island's mollusk fauna is a blend of warm-temperate and subtropical-tropical species.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.128-138
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• 2019

Effects of feeding type and food resource availability on community structure of mollusks inhabiting hard-bottom subtidal areas were investigated. By following guidance from several references, mollusks observed in this study were divided into 5 groups according to feeding type - 1) grazing, 2) filter feeding, 3) deposit feeding, 4) omnivorous and 5) predation. The results showed that both grazing and filter feeders were the most numerous, explaining grazing type in the East Sea accounting for 47.9%, 32.6% in the South Sea and 29.6% for filter feeding, and filter feeding as a dominant feeding type in Yellow Sea accounting for 42.3%. Results of this study showed distinctive difference in community structure depending on mechanism of feeding type and geographical areas where sampling took place. With the results, attempts were made to understand whether community structure could be affected by feeding type or feeding availability and found out that community structure depended heavily on food resource availability. In the East Sea where marine algal density was high, the algal community in the forms of thick-leathery and sheet often occurred in water column with high transparency which provides proper environment for growth. In the South Sea where grazing and filter feeding types were predominated similarly, the algal density was high, but had the relative highest phytoplankton density. Whereas in the Yellow Sea showing the lowest algal biomass compared to the one in the East and the South Sea, and phytoplankton density was similar to those. It might be a adequate environment for filter feeders than grazers. This study concluded that community structure of mollusks showing high abundance was present where food resource availability with types and quantity was high.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.193-204
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• 1983

The Jinyang Lake is dammed up Nam River, and surrounded by Jinju city and four counties; Jinyang, Sanchong, Hading, and Sachon in kyongsang-Nam-Bo, Korea. The areas around this man-made lake have been known as an endemic focus of clonorchiasis in Korea. The present study was first aimed to know the distribution of freshwater mollusks including medically important snails, and larval trematodes shed from Parafossarulus manchouricus and Semisulcospira libertina. In addition to above studies, water analyses in each snail habitat were carried out in order to figure out a part of their environmental factors. This malaco-ecological survey was done at the sirs areas around upper, middle and lower parts of the lake for 4 months, August-November, 1983. Total nine species of freshwater mollusks were collected throughout the study: 4 species of gastropods: Semisulcospira libertina, Cipangopaludina chinensis, Parafossarulus manchouricus and Radin auricularia, and 5 species of bit.alves; Unio dcuglasiae, Ancdonta woodiana, Lamprotula gottschei, Corbicula yuminea and Limncperma lucustris. Out of nine species of freshwater mollusks, three species of gastropods; S. Zibertina, p. manchouricus and R. auricularia were medically important in terms of the transmission of digenetic trematodes to humans. P. manchouricus and R. auricularia were mainly collected from the shallow ponds and the irrigation channels with the muddy basin, but S. libertine and the bivalves were only collected from the stream of Nam River where the gravels and rocks were dominant. The levels of dissolved oxygen (D.O.) and biochemical oxygen demand \(B.O.D._5)\ of the water specimens sampled from the study areas ranged from 6.0 to 9.6 ppm and from 0.4 to 1.6 ppm respectively. As a result, it is considered that water system around the Jinyang Lake might be relatively clean without any heavy pollution of aquatic microorganisms and organic materials during the period of this study. On the other hand, eight metalic constituents from the water samples were also assayed, and all metalic ions detected were remarkably low below the legal criteria. However, calcium ion in the water samples from the habitats of P. manchouricus was considerably higher than others. Infection rates of digenetic trematodes in the snails were 6.9% in P. manchouricus and 4.8% in S. libertine, respectively. P. manchouricus snails harboring with thc cercariae of Clonorchis sinensis were only 0.14% among the snails examined, and other trematode cercariae except cercaria of C. sinensis were: furcocercus cercariae, cercaria of Loxogenes liberum type I and II. S. libertine snails parasitized with the cercariae of Metagonimus yokogawai were 1, 5% out of the snails examined, and no cercaria of Paragonimus westermani was found in S. libertine snails in the present study. Digenetic trematode cercariae other than M. yokogawai observed in S. libertina snails were: Cercaria yoshidae (B type) , Cercaria cristata, Cercaria innominatum, Cercaria of Centrocestus formosanus and Cercaria nipponensis.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.377-384
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• 2012

The importance of biological resources has been gradually increasing, and mollusks have been utilized as main fishery resources in terrestrial ecosystems. But little is known about genomic and transcriptional analysis in mollusks. This is the first report on the transcriptomic profile of Meretrix lusoria. In this study, we constructed cDNA library and determined 542 of distinct EST sequences composed of 284 singletons and 95 contigs. At first, we identified 180 of EST sequences that have significant hits on protein sequences of the exclusive Mollusks database through BLASTX program and 343 of EST sequences that have significant hits on NCBI NR database. We also found that 211 of putative sequences through local BLAST (blastx, E < e-10) search against KOG database were classified into 16 functional categories. Some kinds of immune response related genes encoding allograft inflammatory factor 1 (AIF-1), B-cell translocation gene 1 (BTG1), C-type lectin A, thioester-containing protein and 26S proteasome regulatory complex were identified. To determine phylogenetic relationship, we identified partial sequences of four genes (COX1, COX2, 12S rRNA and NADH dehydrogenase) that significantly matched with the mitochondrial genomes of 3 species-Ml (Meretrix lusoria), Mp (Meretrix petechialis) and Mm (Meretrix meretrix). As a result, we found that there was a little bit of a difference between sequences of Korean isolates and other known isolates. This study will be useful to develop breeding technology and might also be helpful to establish a classification system.