• Parasites, Hosts and Diseases
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• v.24 no.2
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• pp.216-217
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• 1986

호림수산(滸林水産) 양식장(養殖場)에서 사육하고 있는 12개연령(個年齡)의 향어(香魚)(이스라엘잉어) 39마리중 36마리로부터 큰 후흡반(後吸盤)으로 세개내면에 고착(固着)하고 있는 132개체(個體)의 물고기거머리를 1986년(年) 4월(月) 7일(日)에 채집하여 충체(蟲體)의 구조(構造)를 상세(詳細)하게 검토(檢討)하였다. 충체(蟲體)는 짧고 두꺼우며, 전흡반(前吸盤)에는 두 짝의 안점(眼點)이 있다. 후흡반(後吸盤)은 최대체폭(最大體幅)의 $0.3{\sim}0.4$배(倍)이며, 유안점(類眼點)이 없다. 제1측방(第1側方) 돌출부(突出部)는 제(第)2의 것보다 작으며, 제(第)$2{\sim}5$의 것은 크지만 제(第)$6{\sim}11$의 것은 후단(後端)에 갈수록 점점 작아진다. 원체절(原體節)은 3체환(體環)으로 되어 있으며, 다시 작은 구조(溝條)로 분절(分節)되어 있다. 원체절(原體節)에 있어서 체환(體環)의 최다수(最多數)는 14개(個)이다. 이러한 형태학적(形態學的) 특징(特徵)으로 미루어 보아 Trachelobdella sinensis Blanchard, 1896이라고 동정(同定)한다. 이 물고기거머리는 저자(著者)가 우리나라에서 처음으로 발견(發見)하였으며 새로운 분포지역(分布地域)으로서 한국(韓國)을 추가(追加)한다.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.281-288
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• 1994

한국산 거머리(Erpobdella lineate)의 전, 후 흠반을 광학현미경과 투과전자현미경을 사용하여 조직화학적 및 미세구조적 연구를 수행한 결과 다음과 같았다. 거머리 전, 후 홍안에서 관찰된 상피세포는 불규칙한 단층원주형 상피로 되어 있으며, 상피세포의 상단에는 큐티를층이 있고 측면원형질 막은 거치상을 이루면서 여러개의 desmosome이 관찰되 었다. 큐티클층은 projection eplcuticularis, amorphorous stratum 및 fibrous stratum 등 3부분으로 구분되었다. 전, 후 출반의 상피조직 사이에서 공히 a형 분비과립과 b혐 분비과립 등이 관찰되었는데, 이 세포에서 분비된 과립들은 중성점액다당류로 확인되었다. 전 흠반의 횡단면 상피조직 밑에서 많은 근육세포들조 형성된 원형의 집단들이 다수 관찰되었는데, 이는 흠반의 흡수기능과 밀접한 관계가 있었다 비교적 통근형태의 근육세포들은 세포의 원형질막 내측에 많은 근섬유 다발을 지니고 있고 그 중앙에는 cristae가 발달된 많은 수의 사립체들이 모여 있었다. 전, 후 출반의 결합조직 내에서 5종류(A, B, C, D 및 I 등)의 분비과립들이 관찰되었다. 그 중 C, D 과립은 전, 후 흡반에서 공통으로 관찰되고, A, B 과립은 전 흠반에서, E 과립은 후 흠반에서만 각각 관찰되었는데, 이들 역시 모두 중성점액다당류로 확인되었다.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.313-320
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• 2001

An ecological study was conducted to determine the geographic distribution, community structure, and habitat characteristics of eelgrass, Zostera marina L. beds along the southern coast of Korea. Plants and sediment samples were collected during June 2000 and December 2000 on twenty-eight locations, including two Cheju Island stations, which were used to compare morphological characteristics with habitat types. Z. marina populations existed from the intertidal to subtidal zone, mainly in the bays along the coast and the island, the barrier reef, and the estuary where the water depth was 0.5${\sim}$8.0m. Salinity range in Z. marina beds ranged 18.2 to 34.5%$_o$. Sediments of Z. marina beds contained 49.7${\sim}$99.1% of sand and were classified into sand, muddy sand, and sandy mud. Mean grain size varied from 1.5 to 4.4 phi. Height of vegetation shoots varied from 54.7 to 171.4 cm, depending on water depth, location, substrata and habitat types. quantitative morphological features that enabled recognition of the two phonetic groups were short-narrow leaf type and long-broad leaf type. Statistical analysis indicated that biomass of individual plants and their quantitative morphological characteristics were significantly correlated.

• Ocean and Polar Research
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• v.27 no.1
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• pp.67-74
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• 2005

The phonology and reproductive effort of Zostera marina L. (Dongdae Bay and Aenggang Bay) on the southern coast of Korea were investigated from September 2002 to August 2003. The Dongdae Bay(DB) exhibited a finer sediment grain size with richer organic content than the Aenggang Bay(AB). Water temperature at DB site ranged from $7.5^{\circ}C$ in February to $25.5^{\circ}C$ in August, while water temperature at AB site ranged rrom $6.7^{\circ}C$ in February to $25.2^{\circ}C$ in september. Both populations exhibited a perennial lifB span, but the sexual reproductive effort was significantly higher at DB than AB. The reproductive shoots of DB site were developed from February to June 2003, while those of AB site from March to June 2003. At DB site, the frequency of reproductive shoot ranged from 11 to 33%, whereas reproductive shoot of AB did below 5%. Reproductive structures were larger and more abundant at DB, with the exception of number of fruits and seeds per spadix. Water temperature seems most important to regulate the timing of reproductive phase of Z. marina populations for two study sites.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.70-77
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• 2003

From March 1998 to August 2000, the phenological and morphometric changes of Zostera marina L. were examined at the Duksan Port in the eastern coast of Korea. Morphometric characteristics, phenological stage, shoot density, biomass of Z. marina population and environmental parameters were also measured. Nutrient levels in water column varied over the season. Morphometric characteristics of vegetative shoot changed with season; shoot heights ranged from 54.2 cm (March) to 100.0 cm (October). Reproductive shoots appeared from mid-March to early September of which the height was ranged from 97.8 cm (March) to 213.0 cm (July). The flowering phase started at 12$^{\circ}C$ and the fruit development was resulted up to 21$^{\circ}C$. The seed maturing was developed at 22$^{\circ}C$-$25^{\circ}C$. Shoot density and biomass in permanent quadrate (0.25 m$^2$) were significantly different among seasons ranging from 38 to 136 shoots (mean 80.3$\pm$6.5) for shoot density, and 190 g dry wt m$^{-2}$ in October 1998 to 922 g dry wt m$^{-2}$ in June 1998 for biomass respectively. Relationships between shoot morphometrics and physico-chemical parameters were not significantly correlated. Seasonal changes in water temperature seemed responsible for the replacement of reproductive phases and the annual changes of shoot morphometrics in Z. marina populations.

• Journal of fish pathology
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• v.23 no.3
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• pp.399-407
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• 2010

On the inner side of each operculum of the crucian carp, Carassius auratus (n=10), the leech, Limnotrachelobdella sinensis of 1-4 individuals were parasitic. The leeches had approximately 41.0 mm in total length and 11 mm in width. These body was composed with anterior sucker, neck, trunk and posterior sucker and average length was 2.3 mm, 7.2 mm, 23.3 mm and 8.7 mm respectively. To both sides of the trunk lateral vesicle of 11 pair existed. When observed by SEM, anterior sucker was hemisphere shape and the mouth where proboscis comes out existed with the its center. Proboscis was connected the esophagus directly. Under light microscopy, bloodsucking gill of C. auratus showed lamella fusion, hypertrophy the epithelial cell of the filament and lamella, increased mucocytes and congested capillaries. On the other hand, necrotic and hydropic degeneration epithelial cell of the lamella, and infiltration of the macrophages from some individuals were suggested the secondary infection with the bacteria or virus after bloodsucking activity of the leech.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.336-341
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• 2000

This study was conducted to clarify the habitat characteristics and distribution of seagrass. Zostera marina L. (Zosteraceae) in the brackish Hwajinpo Lake, Korea in June 1998 and July 2000. Z. marina beds were distributed along the sea-side cost of the lower lake mouth at 0.8 to 1.5m in death, and the seagrass bed area was about 3,200 m$^{2}$. Salinity, water temperature and pH were in the range of 8.0${\sim}$23.0$%_{o}$, 22.0${\sim}$23.7$^{\circ}C$ and 8.34${\sim}$8.62, respectively. Nutrient concentrations were generally now (TN: 24.34 ${\mu}$M, NH$_{4}$-N: 2.57 ${\mu}$M, NO$_{3}$-N: 0.56 ${\mu}$M, NO$_{2}$-N: 0.27 ${\mu}$M, TP: 2.08 ${\mu}$M, PO$_{4}$-P: 0.34 ${\mu}$M). Suspended particulate matters (SPM) concentration averaged 62.8 mg/l and particulate organic matter (POM) averaged 21.3 mg/l. Organic content of SPM averaged 33.9%. The beds substratum was composed of well-sorted, fine sand and its mean brain size was 3.13${\Phi}$. The Z. marina vegetation was almost submerged, and the morphological characteristics can be classified as steno-leaf phenotype by the shoot length, leaf width, and number of leaf vein. Shoot length and leaf width were 70.0${\sim}$126.5 cm and 5${\sim}$7 mm, respectively. Shoot densities ranged from 264 to 296/m$^{2}$, and the plants biomass was estimated at 332.6 to 373.0 g dw/m$^{2}$. Therefore, the habitats of Z. marina in Korea were recognized in a brackish lake, and morphological characteristics appeared to be variable.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.43-52
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• 2015

The growth and population dynamics of eelgrass (Zostera marina) due to changes in sediment composition were examined in the lower intertidal zone of the Seomjin Estuary, Korea. We surveyed environmental factors such as water temperature, underwater irradiance, main types and organic content of sediment, tidal exposure, and nutrient concentrations in the water column and sediment pore water, in relation to the shoot density, biomass, morphological characteristics, and growth of Z. marina inhabiting lower intertidal zones. The survey was conducted monthly from May to December of 2004 and 2009. The water temperature showed obvious seasonal trends in both study years. Underwater irradiance was significantly higher in 2009 than in 2004. Tidal exposure was not significantly different between 2004 and 2009. The sediment was muddy-sand in 2004 but became sandy and with a significantly lower organic content in 2009. Water column $NH_4{^+}$ concentrations were significantly higher in 2004 than in 2009. Sediment pore water $NO_3{^-}+NO_2{^-}$ concentrations were significantly higher in 2009 than in 2004. Other nutrient concentrations did not differ significantly between 2004 and 2009. Morphological characteristics, including eelgrass length and leaf width were significantly lower in 2009 than in 2004. Eelgrass shoot height, leaf length, and sheath length showed typical seasonal patterns, increasing in early summer and decreasing in autumn, in both years. Vegetative shoot density was not significantly different between 2004 and 2009, while the biomass of individual plant parts and the total biomass were significantly lower in 2009. Eelgrass leaf productivity did not differ between years, but leaf turnover time was significantly shorter in 2009 than in 2004. Eelgrass downsizing and decreased turnover time in 2009 compared to 2004 indicate more effective adaptations to the stress of long-term changes in sediment composition. Overall, results suggest that changes in sediment composition can be a limiting factor for seagrass growth in the intertidal zone.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.154.3-155
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• 2001

• Proceedings of the Korean Society of Soil Zoology Conference
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• 1998.10a
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• pp.7-7
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• 1998