• Journal of Aquaculture
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• v.19 no.3
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• pp.216-221
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• 2006

The Effect of different temperatures and photon irradiance on the growth of crust and the regeneration of tissue fragments of the commercially important red alga Grateloupia acuminat Okamura were examined in laboratory cultures. The tetraspore developed into basal crusts and produced upright thalli. Crust grew very fast at $25^{\circ}C$ and $80{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ after one week in indoor culture. However, they stopped growing after three weeks. Maximum growth was $275{\mu}m$ in diameter. They required four weeks to get upright thalli at $5^{\circ}C$, while only three weeks were required at $10^{\circ}C$. When different light intensities were compared at $15^{\circ}C$, cells of the crusts were well differentiated $80{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and consistently divided so that upright thalli were produced. In aeration culture, the upright thalli grew up to 6.5 cm in length within 4 months. Thus, it is possible to produce mass cultures of Grateloupia in the field. In addition, female and male gametophytes developed from the tetraspores and they were fertilized to produce tetrasporohyte thalli. By this procedure, the normal life cycle of the red alga G. acuminata was completed.

• ALGAE
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• v.38 no.2
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• pp.151-157
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• 2023

Grateloupia turuturu is a red alga with a flat but firm slippery thallus. Throughout its lifetime, this alga experiences a wide range of environmental stresses in the intertidal rocky shores. The aim of this study is to investigate the effect of salinity and irradiance on the early developmental stages of G. turuturu tetrasporophytes. The released carpospores were cultivated at different salinities (S = 15, 25, and 35) and irradiances (50, 100, and 200 μmol photons m^-2 s^-1). Germination of carpospores and development of juvenile tetrasporophytes were observed every 5 days and recorded by a digital camera. Discoid crusts were formed at all conditions within 5 days. The discoid crusts at 200 μmol photons m^-2 s^-1 died within 20 days regardless the salinity. The discoid crusts at S = 35 also died at all irradiance conditions within 25 days. Except for those at S = 35 and 200 μmol photons m^-2 s^-1, the discoid crusts reached about 8,000-9,000 ㎛² by day 20. Regardless of irradiance, the upright thalli formation rate from discoid crusts was 85 and 10% at S = 15 and S = 25, respectively. These results suggest that salinity and irradiance are important factors influencing early developmental stages of G. turuturu.

• Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.13.1-13.8
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• 2016

Reproductive phenological pattern on tetrasporophytes and carposporophytes of Grateloupia subpectinata thalli were observed at Yangyang, on the middle east coast of Korea from January to December 2013. DNA sequences of cox1 gene from 48 selected samples were compared to assure that sample collection is single species, and they were all identical G. subpectinata. Density, length and width of thalli were significantly changed monthly. The maximum of density, length and fresh weight occurred in September, and continuous growth was observed during the autumn and winter. Tetrasporophytes were grown dominantly in October and November, whereas carposporophytes were dominated in September and March. Upright thalli disappeared in June and July and then juveniles were abundant in August. There was a significant difference in length between tetrasporophytes and carposporophytes. These reproductive pattern and seasonality together with phenological data of G. subpectinata would provide valuable information about successful seedling supply for aquaculture of the species in the future.

• ALGAE
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• v.24 no.3
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• pp.163-168
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• 2009

Grateloupia filicina (J.V. Lamouroux) C. Agardh (Halymeniaceae, Cryptonemiales, Rhodophyta) is an edible seaweed as well as an important source of carrageenan. In the present study, attempt has been made to develop a suitable protocol for effective regeneration of the seaweed and the rapid multiplication of the desired varieties. The young upright thallus of G. filicina was grown in axenic culture using both solid and liquid media. The various media tested were f/2, Provasoli’s Enriched Seawater (PES) and Enriched Seawater (ESW). The effect of glycerol (as a carbon source) and various plant growth regulators i.e. auxin (NAA) and cytokinins (Kinetin and BA) were tested. Although, regeneration of young thalli was observed from the cut ends in all the media, better growth was found in f/2, PES, f/2 (0.5% Glycerol), f/2 (NAA ${10^{-5}}_M)\;and\;f/2\;(BA\;{10^{-6}}_M$). On the other hand callusing was observed only in solid media supplemented with low concentration of Glycerol (0.5%) in f/2, NAA ${10^{-5}}_M\;in\;f/2,\;PES\;and\;BA\;{10^{-5}}_M$ in f/2. Young thalli were developed from the callus sub culture after 40 days of inoculation.