The purpose of this study is to determine the optimum physical growth conditions of free conchocelis of the red alga Neopyropia tenera (Asakusa-Nori). To achieve this, experiments were conducted under combined conditions of water temperature and light irradiance, as well as under shaking and static conditions.
Experiments under combined water temperature and light irradiance conditions were conducted at four water temperatures (10, 15, 20, 25 ℃) and five light irradiances (25, 50, 75, 100, 125 µmol m^-2s^-1) for a total of 20 experimental plots. The maximum % daily growth rate of 23.98±8.48 was obtained in the experimental plot with water temperature of 20 ℃ and light irradiance of 50 µmol m^-2s^-1. The % daily growth rate was 13.17±6.54 under shaking conditions and 12.73±7.10 under  static conditions, showing no significant difference (p > 0.05) between the experimental plots. As a result, based on the above, the optimal culture conditions for N. tenera free conchocelis were found to be 20 ℃ water temperature, 50 µmol m^-2s^-1 light irradiance, and static conditions. However, there are still some unknowns, such as the formation of conchosporangium and the effect of aeration, that need to be clarified in the future.

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Wakame (Undaria pinnatifida) in Japan is mainly produced by aquaculture, and juvenile sporophytes are used as sporelings in wakame aquaculture. In this study, we used three types of LED light (red, green, and blue) and fluorescent light to evaluate the effects on the growth of sporophytes (blade area) and holdfasts.
The daily growth rate calculated from the blade area of the sporophyte was higher at 59.5 ± 6.2 % under blue light and lower at 43.0 ± 5.7 % under red light. Regarding the area and a number of holdfasts, blue and fluorescent lights had a larger area and the number. On the other hand, red light had the lowest values for both. An evaluation of the above revealed that the use of blue LED is suitable for sporeling production after the fertilization of gametophytes.

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