著者

李 正根 平山 和次

出版者

長崎大学水産学部

雑誌

長崎大学水産学部研究報告 (ISSN:05471427)

巻号頁・発行日

no.71, pp.p163-168, 1992-03

被引用文献数

1

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The population growth of Noctiluca scintillans was investigated, using Tetraselmis tetrathelle as food, at salinities ranging from 8.5-34‰, food levels from 1×10³-8×10⁵ cells/ml and temperatues from 5-32℃. Under every experimental condition, ten to twenty Noctiluca were grown individually in 1 or 3ml of food suspensions for three to four days. The specific growth rates were obtained from the linear regression analysis of the population growth. Salinity: The specific growth rate was maximal at approximately 22‰, and decreased differentially with increasing or decreasing salinities. The lowest salinity for the minimal and continual growth was 14‰, but the sudden drop from 34‰ to 14‰ was lethal. Food Level: There was little growth at the food levels lower than 3×10⁴ cells/ml. At food levels between 3×10⁴ and 3×10⁵ cells/ml, the specific growth rate increased proportionally with increasing food levels. With further increases in food level, the rate increased asymptotically. The values of the specific growth rates were 0.03 (S. D; 0.16) at 3×104 cells/ml, 0.74 (S. D; 0.16) at 3×10⁵ cells/ml and 0.81 (S. D; 0.12) at 8×10⁵ cells/ml. Temperature: The specific growth rate was maximal around 23℃, and decreased differentially with increasing or decreasing temperatures. All Noctiluca died at 32℃ within a day. It grew at 5℃ normally but slowly.