• Fisheries and Aquatic Sciences
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• 제4권4호
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• pp.257-260
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• 2001

The effects of light, desiccation and salinity on the discharge of spores in Korean agarophyte, Gracilaria verrucosa were studied. Among the examined factors, light after darkness was the most effective for spore discharge. The maximum release of tetraspores was induced at 24 h after the treatment. Desiccation also seems to be conductive to the release of tetraspores. However, its effect, as in treatment of distilled water for salinity, was hardly found in induction of carpospore discharge. This may suggest that spore discharge in this alga is primarily related with photoperiodic rhythm. Also it appears that the amount of light energy received by fertile thalli also significantly affects to the spore release, considering relationship between the amount of the discharged spores and the elapsed time after treatment.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.108-113
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• 2002

Apical and subapical fragments of Gracilaria verrucosa (Hudson) Papenfuss (Rhodophyta) were cultured on a temperature-light gradient table with four temperature $(15,\;20,\;25\;and\;30^{\circ}C)$ and five light intensity $(20,\;40,\;60,\;80\; and\;100{\mu}mol\;photons\;m^{-2}s^{-l})$ regimes to examine growth responses. Their growth was measured weekly. Plant weight and lateral branch formation were affected by temperature and light intensity. As compared with other reports, relative growth rate (RGR) in both fragments was more or less high with 6.27 to $11.95\%$ $day^{-1}$. It was lowest at $15^{\circ}C$ with $20\mu mol$ photons $m^{-2}s^{-l}$, whereas, the highest value was recorded at $25^{\circ}C$ with $100\mu mol$ photons $m^{-2}s^{-l}$ During the experimental period, the growth pattern in G. verrucosa was significantly different between apical and subapical fragments, even though RGR based on weight was similar. Growth in apical fragments depended on elongation by apical growth. By contrast, subapical fragments mainly increased their weights by proliferation of lateral branch. This suggests that intercalary activity (e.g. lateral branch formation) is also an important means for growth of the thallus in Korean G. verrucosa. In conclusion, the relatively high growth potential with the intercalary activity in G. verrucosa will be helpful for mariculture in Korea.

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.147-151
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• 1998

The reproductive phenology of Gracilaria verrucosa was studied in Cheongsapo near Pusan, Korea. Among the life history phases, tetrasporic plants occurred dominantly in varying degrees of abundance throughout the year except from July to September. Cystocarpic plants increased rapidly during summer, and then recorded maximum abundance in July. Whereas, seasonal peaks of spermatangial plants were observed in April and September. However, they were less than cystocarpic plants in abundance. Vegetative plants dominated from December to May for long period, with a occurrence peak in February. Even though fertile plants in both gametophytes and tetrasporophytes occurred throughout the year, their seasonal abundance suggests that the positive correlation between reproduction and water temperature is basically found in the reproductive pattern of Gracilaria verrucosa. The distributional aspect of life history phases appears to be related with differences of their longevity, fecundity or survivorship.

• 환경생물
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• 제30권3호
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• pp.193-199
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• 2012

We performed qualitative and quantitative surveys on the distribution of seaweed species and dominant species with their standing crop and temporal variations in Hauido tidal flats in order to understand the role of seaweeds in a coastal wetland ecological system that may be used for conservation and management of coastal wetland ecological system. A total of 9 species were found at 7 stations of the study area; 4 species of Chlorophyta (Ulva compressa, U. prolifera, U. pertusa and Ulothrix flacca), 3 species of Phaeophyta (Ectocarpus arctus, Scytosiphon lomentaria and Myelophycus simplex) and 2 species of Rhodophyta (Gracilaria verrucosa and Caulacanthus okamurae). Major dominant species were U. compressa, U. prolifera and U. pertusa (Chlorophyta), Scytosiphon lomentaria (Phaeophyta) and Gracilaria verrucosa (Rhodophyta). Standing crops of U. compressa and U. prolifera were $2.94{\sim}45.25g{\cdot}dw{\cdot}m^{-2}$ and $6.19{\sim}91.9g{\cdot}dw{\cdot}m^{-2}$, respectively, in spring. Seaweed habitat was characterized by textural differences that the percentage of coarse particles and organic material were a little higher in seaweed flourishing areas than in seaweed barren areas.

• Journal of Plant Biology
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• 제38권4호
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• pp.389-398
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• 1995

한국 서해 중부 연안의 12개 지소에서 조간대 해조류의 종조성과 생물량을 조사하였다. 조사지역에서 채집 동정된 해조류는 남조식물 19종, 녹조식물 20종, 갈조식물 32종 및 홍조식물 80종으로 총 151종이었다. 이 가운데 지충이(Sargassum thunbergii), 마디털(Stylonema alsidii) 및 꼬시래기(Gracilaria verrucosa)의 3종이 12개 조사지소 모두에서 출현하였다. 단위면적당 해조류 생물량은 백사장과 대천에서 41 g dry $wt{\cdot}m^{-2}$의 매우 낮은 평균 생물량을 보인 반면, 조사지역 가운데 가장 북쪽에 위치한 의항리에서 549 g dry $wt{\cdot}m^{-2}$로 가장 많았는데, 이 수준은 지금까지 서해안에서 측정된 해조류 생물량 가운데 가장 많은 양이다. 해조류의 문별 생물량 구성비율은 전반적으로 갈조식물이 가장 높게 나타난 반면, 녹조식물이 가장 낮았다. 출현종 가운데 지충이는 모든 조사지소에서 조간대 전반에 걸쳐 우점적인 생육을 보였다. 그러나 산호말류(Corallina spp.)는 조사지역의 상부인 태안반도의 지소들에서 우점적인 생육을 보였고 하부의 지소들에서도 부분적으로 출현하였으나, 중부의 지소들에서는 거의 출현하지 않는 분리 분포를 보였다.