Permalink : http://hdl.handle.net/2115/51115

KEYWORDS : Red tide;Chattonella marina;Growth;Nutrients

Growth of the fish-killing raphidophyte Chattonella marina MS3-P was examined in the 200 mL modified SWM-3 culture medium in a 500-mL flask at a temperature of 25C with light intensity of 120 mol photons m-2 sec-1 under a photo-cycle of 14hL-10hD. Growth conditions were supposed to be ideal and sufficient to achieve the potentially maximum growth rates, and the obtained growth rates were 1.42 and 1.48 divisions day-1. C. marina MS3-P also grew in the filter-sterilized (0.1 m pore) seawater (collected in winter) with a growth rate of 0.81 divisions day-1, suggesting a possibility that C. marina can reach from the cell density of several cells mL-1 to the red tide level of several hundreds cells mL-1 (fish-killing level) or higher within about a week. These rather higher growth rates presumably contribute to form harmful red tides in the coastal seas of Japan such as the Seto Inland Sea, Yatsushiro Sea, and other embayments.