Effects of environmental factors on growth and survival of Gloiopeltis furcata thalli

The experiment investigated the effects of temperature, light intensity, salinity and nutritional salt ongrowth of Gloiopeltis furcata thalli as well asinfluences of pH, exposure to air and freshwater immersion on the survival of G.furcata thalli. G.furcata thalli were incubated at different temperatures (10 ℃, 14 ℃, 18 ℃, 22 ℃, 26 ℃) with different light intensities (photons) (2 500 lx, 4 500 lx, 6 500 lx, 8 500 lx and10 500 lx) in different salinities (15.5, 18.0, 20.5, 23.0, 25.5, 28.0, 30.5, 33.0, 35.5, 38.0) and by different concentrations of nutritional salt(adding NaNO3 of 10 mgL-1, 20 mgL-1, 40 mgL-1, 80 mg L-1and corresponding K2HPO4 of 1 mgL-1, 2 mgL-1, 4 mgL-1, 8 mgL-1 ) for 21 d. The results show that the optimum environment factors for growth of G.furcata thalli were temperature 10~14 ℃, light intensity 6 500~10 500 lx and salinity 18~38; nutritional salt of different concentrationis had no significant effect on its growth. G.furcata thalli which were incubated in sea water with different pH (5.5~10.0) for 10 dcould survive under pH 6.5~9.0. G.furcata thalli, which were dried in shade, immersed in freshwater and dried in the sun for different time, could normally survive after being dred in shade for 24 ~48 h or immersed in freshwater for 24~48 h, and those were immersed in freshwater for 3 h after being dried in shade for 3 h could also survive. G.furcata thalli could not normally survive after being dried in the sun for more than 2 h.