Effects of salinity, light intensity and sediment on growth, pigments, agar production and reproduction in Gracilaria tenuistipitata from Songkhla Lagoon in Thailand

摘要: SUMMARY The effects of salinity, light intensity and sediment on Gracilaria tenuistipitata C.F. Chang & B.M. Xia growth, pigments, agar production, net photosynthesis rate were examined in the laboratory under varying conditions salinity (0, 25 33 psu), (150, 400, 700 1000 µmol photons m−2 s−1) 0.67 2.28 mg L−1). These simulated field conditions, to gain some understanding best for cultivation G. tenuistipitata. The highest growth was at psu, 700 µmol photons m−2 s−1 with no sediments, that provided a 6.7% increase weight gain. production (24.8 ± 3.0 %DW) 150–400 µmol sediment. pigment contents phycoerythrin (0.8 ± 0.5 mg g−1FW) phycocyanin (0.34 ± 0.05 mg g−1 FW) produced low 150 µmol m−2 s−1. 161.3 ± 32.7 mg O2  g−1 DW h−1 400 µmol without short period cultivation, (3 days) 60.3 ± 6.7 mg O2 g−1 DW h−1 25 psu, long (20 days). results indicated most crucial factor affecting G. tenuistipitata production. This would help promote back into lagoon using these now determined baseline conditions. Extrapolation from study it possible obtain two crops year lagoon, good yields agar, mid-January end April (dry season), mid-July September (first rainy season) when restricted.