A simple alternative to separate filamentous bodies of Monostroma latissimum algae (large green algae) as seed stock. The filamentous bodies are easily separated and prepared for cultivation. At low luminosity (50 μm mole s−1m−2), the filamentous bodies grow into the filamentous colony. If the filamentous colony is in turns irradiated at the luminosity greater than 100 μm mole s−1m−2, it is turning into fronds. Thereby the filamentous bodies are evenly distributed into small segments so as to penetrate through the cotton rope for algal mass cultivation and further grow into fronds at high luminosity.
