Fundamental studies on physiology of rotifer for its mass culture: III. Influence of phytoplankton density on population growth
Hirayama, K.; Watanabe, K.; Kusano, T. (1973). Fundamental studies on physiology of rotifer for its mass culture: III. Influence of phytoplankton density on population growth. Bull. Jpn. Soc. Sci. Fish 39(11): 1123-1127
In: Nippon Suisan Gakkaishi = Bulletin of the Japanese Society of Scientific Fisheries. Japanese Society of Scientific Fisheries: Tokyo. ISSN 0021-5392; e-ISSN 1349-998X, more
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| Authors | | Top |
- Hirayama, K.
- Watanabe, K.
- Kusano, T.
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| Abstract |
The population growth of the rotifer, Brachionus plicatilis cultured with a marine sp of Chlorella suspended at various densities was investigated. Experiments were performed by culturing many individuals in many test tubes each containing 2 individuals in the experimental medium. From daily counts of eggs laid and surviving individuals, time intervals from hatching to 50 per cent survival and to peak of fecundity, net reproduction rate, intrinsic rate of population increase and mean generation time were estimated. The results obtained are summarized as follows. (1) The values of the indices concerning population growth of the rotifer indicate that for its mass production the marine Chlorella should be kept always at the density of 85-213 x 104 cells/ml, where 150 x 104 cells/ml may be the most desirable because of the highest values of intrinsic rate of population increase and net reproduction rate. (2) Population growth of the rotifer can be restrained in Chlorella suspension even at the density (less than 213 x 104 cells/ml) where the rotifer cannot reach a satiated condition. (3) The wt and vol of the Chlorella were estimated at 7.1 x 10-6 µg and 1 x 10-8 mm3 per average cell, respectively. Therefore, the most suitable density for population growth of the rotifer is estimated as 10.7µg/ml or 1.5 x 10-2 mm3/ml. |
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