• Ocean and Polar Research
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• 제44권1호
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• pp.39-59
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• 2022

How in the Antarctic icefish, generally, and Pseudochaenichthys georgianus, in particular, otoliths increase in size and build new material as the fish ages and passes through different life phases is largely unexplored. Morphometric details of 3418 otoliths of Ps. georgianus from S. Georgia and 318 from S. Shetland, were processed and proportions of the amounts of collagen and aragonite removed by EDTA were determined for different age groups. Microstructural investigations showed that characteristics of the 3-dimensinal collagen net are the reason for the radial direction and orientation of the aragonite needles of approximately 1.0 ㎛ in length in larval and 2.3 ㎛ in length in adult specimens. Earlier generated increment layers from the primordial centre (PC) in the dorsal direction restrict those of the secondary centre (SC), causing new growth layer accretion in different directions. In the otoliths of larval Ps. georgianus, aragonite layers are 0.89 ㎛ wide while in juveniles and adults they measure 1.45-2.86 ㎛. Otoliths change from a sphere shape in the larvae to a longish object of irregular outline in the older stages. It is tentaively suggested that the observed otolith shape differences at distinct growth stages are due to physical effects related to swimming speeds at particular water depths and locations. To confirm that otoliths, apart from being useful for age analyses, could also serve to establish correlations between developmental stage and the oceanic environment the fish spend time in, further analyses using additional species and state-of-the-art methods like µCT imaging to evaluate otolith volumes and shapes are required.

• 한국해양학회지
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• 제29권4호
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• pp.366-375
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• 1994

1991년 8월과 10월, 1992년 1월과 4월에 아산만의 30개 정점에서 채집된 동물플랑 크톤의 분포특성을 조사하였다. 동물플랑크톤의 출현 개체수는 240-1,458개체/m$^3$의 범위를 보였으며 요각류는 채집된 동물플랑크톤의 평균88%를 차지하여 가장 우점하였 다. Acartia bifilosa는 가을부터 봄에 걸쳐 우점 하였고, A. pacifica는 여름, Paracalanus parvus는 가을에 우점하였다. 동물플랑크톤의 수평분포는 식물플랑크톤의 분포와 밀접한 연관을 가져, 특히 식물플랑크톤의 출현개체수가 높은 봄에 높은 상관 관계 ($r^2$=0.66, p<0.01,n=30)를 보였다. 치자어의 출현개체수가 높은 여름에 동물플 랑크톤과 치자어의 수평 분포양상도 밀접한 관계를 가졌다. 동물플랑크톤의 출현개체 수에 의한 정점간 유사도를 집괴분석한 결과 본 해역은 내만과 외만으로 뚜렷이 구분 되었다.

• Journal of the korean society of oceanography
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• 제33권1-2호
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• pp.18-27
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• 1998

Based on 53 quantitative samples collected in April (23 stations) and August (30 stations) of 1993, the species composition, distribution and abundance of macrobenthic invertebrates and bottom characteristics in Chonsu Bay were conducted. Bottom sediments consisted of mud at the close to the dyke, sandymud in the central bay, and coarse sand in the mouth of the bay. A total of 273 species (177 species in April and 200 species in August) were identified. Mean density per sampling station was 480 ind./m$^2$ in April and 1126 ind./m$^2$ in August, respectively. Number of species and densities decreased in the northern part of the bay. The macrobenthos showed a temporal difference in species composition, range of distribution, and community delimitation caused by larval settling. Although during the settling period in summer, large numbers of juveniles added in most of regions, unrelated to environmental conditions, but, successful recruitment may has been a rare event locally Theora fragilis (bivalve), Lumbrineris longifolia(polychaete), Neptys oligobranchia (polychaete) were numerically dominant, but their densities varied seasonally. Community structures of macrobenthos in Chonsu Bay were affected by several bottom environmental conditions, related to tidal current speed, regionally.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.291-301
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• 2013

The genomic organization, tissue distribution, and developmental expression of two paralogous GAPDH isoforms were characterized in the mud loach Misgurnus mizolepis (Cypriniformes). The mud loach gapdh isoform genes (mlgapdh-1 and mlgapdh-2) had different exon-intron organizations: 12 exons in mlgapdh-1 (spanning to 4.88 kb) and 11 in mlgapdh-2 (11.78 kb), including a non-translated exon 1 in each isoform. Southern blot hybridization suggested that the mud loach might possess the two copies of mlgapdh-1 and a single copy of mlgapdh-2. The mlgapdh-1 transcript levels are high in tissues requiring high energy flow, such as skeletal muscle and heart, whereas mlgapdh-2 is expressed abundantly in the brain. Both isoforms are differentially regulated during embryonic and larval development, during which their expression is upregulated with the progress of development. Lipopolysaccharide challenge preferentially induced mlgapdh-2 transcripts in the liver. Therefore, the two isoforms have diversified functionally; mlgapdh-1 is associated more closely with energy metabolism, while mlgapdh-2 is related more to stress/immune responses, in the mud loach.

• 한국어류학회지
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• 제26권2호
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• pp.133-138
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• 2014

진해만에서 동계기간 동안 자어의 분포 및 종조성에 관하여 조사하였다. 조사기간 동안 8과 12종이 출현하였고, 우점종으로는 Pholis crassispina, Clupea pallasii, Liparis tanakae, Hexagrammos otakii였다. 이들 4종은 출현한 총 개체수의 93%를 차지하였다. 잠도와 칠천도 동쪽에서 높은 밀도와 종 다양성을 보여, 이 지역이 진해만에서 자어의 주요 산란장인 것을 의미한다.

• 환경생물
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• 제36권2호
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• pp.232-240
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• 2018

본 연구는 거친대추멍게(Ascidiella aspersa)의 알 발육과 유생 부착에 미치는 수온과 염도의 영향을 파악하고자 실시하였다. 거친대추멍게 알 발육과 유생 부착 실험은 12개의 수온 조건(6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, $28^{\circ}C$,과 2개의 염도 조건(30, 34 psu)에서 진행하였다. 거친대추멍게 알의 부화율과 발육률은 염도에 관계없이 수온이 높아짐에 따라 증가하는 경향을 보였으며 최적 수온 범위 이후 감소하는 경향을 보였으며 부화 및 발육을 위한 최적 수온은 $20{\sim}22^{\circ}C$의 범위를 보였다. 저온 발육임계수온은 30 psu와 34 psu에서 각각 $1.5^{\circ}C$와 $1.8^{\circ}C$로 큰 차이를 보이지 않았다. 부착률은 염도에 관계없이 $16{\sim}22^{\circ}C$의 최적 수온 범위를 보였으며 부착시간은 수온이 증가함에 따라 지속적으로 증가하였다. 결과적으로 거친대추멍게의 최적 발육 및 생존 수온은 염도 조건에 관계없이 $20{\sim}22^{\circ}C$ 범위를 보였다. 본 연구결과는 국내 양식장에서의 거친대추멍게에 의한 경제적 피해가 증가하고 있는 시점에서 거친대추멍게의 분포 및 발생시기를 예측하고 확산 방지 및 방제 방안을 구축하는 데 활용될 수 있을 것으로 생각된다.

• 생명과학회지
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• 제5권2호
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• pp.63-69
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• 1995

Cockroach antigen have been known as a cause of allergic disease. German ockroach(Blattella germanica L.) was chosen because it has the highest distribution range and poulation density. To identify the common and specific antigens of adult and larval stage of german cockroach, we made monoclonal antibodies which were confirmen by SDS-PAGE and EITB. Anti-B. germanica antibody producing hybridomas were 24 among the total 960wells. Only 4 hybridomas did not have cross reaction to other species of cockroach and hluse dust mites(Dermatophagodies farinae and D. pteronyssius). SDS-PAGE revealed about 20 bands from 90Kd to 15Kd to 15Kd. ETB showed specific antigens a6 60, 72 and 82Kd which were experimented by the culture supernatant of 4 selected hybridomas. Especially 60Kd coincided with a band of immunized mouse sera.

• 생명과학회지
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• 제5권2호
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• pp.7-7
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• 1995

Cockroach antigen have been known as a cause of allergic disease. German ockroach(Blattella germanica L.) was chosen because it has the highest distribution range and poulation density. To identify the common and specific antigens of adult and larval stage of german cockroach, we made monoclonal antibodies which were confirmen by SDS-PAGE and EITB. Anti-B. germanica antibody producing hybridomas were 24 among the total 960wells. Only 4 hybridomas did not have cross reaction to other species of cockroach and hluse dust mites(Dermatophagodies farinae and D. pteronyssius). SDS-PAGE revealed about 20 bands from 90Kd to 15Kd to 15Kd. ETB showed specific antigens a6 60, 72 and 82Kd which were experimented by the culture supernatant of 4 selected hybridomas. Especially 60Kd coincided with a band of immunized mouse sera.

• Animal Systematics, Evolution and Diversity
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• 제37권1호
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• pp.84-87
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• 2021

The subgenus Idioglochina Alexander, 1921 belongs to the genus Dicranomyia Stephen, 1829 and has a special habitat unlike other congeners. The larval stage inhabits marine algae near the intertidal zones. The most distinctive characters are found in the antennae with inner face of flagellar segments extended to produce a serrate form. A total of 30 species of the subgenus Idioglochina are recorded with the distribution is restricted to the Pacific and Indian Ocean regions. In this study, the subgenus and its species D. (I.) tokara (Nobuchi, 1955) are newly added to the Korean fauna. This species was previously recorded in Japan as an endemic species, but it was collected from Jeju Island. A redescription, period of activity, habitat information, and photographs of diagnostic characters of the species are provided. The female ovipositor is photographed for the first time.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.33-41
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• 2004

The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (＞1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.