Zh. V. Markina, N. A. Aizdaicher - The effect of lowered salinity of sea water on the growth and photosynthetic pigment content in three strains of the microalga Pseudo-nitzshia pungens (Grunow ex. P.T. Cleve) Hasle, 1993 (Bacillariophyta)

BIOLOGIYA MORYA, 2016, Vol. 42, No. 5, pp. 354-358

The effect of lowered salinity of sea water on the growth and photosynthetic pigment content in three strains of the microalga Pseudo-nitzshia pungens (Grunow ex. P.T. Cleve) Hasle, 1993 (Bacillariophyta)

A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok 690041

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The effect of lowered salinity on the growth and the content of photosynthetic pigments (PP) of chlorophyll a and of carotenoids was studied in three strains of the microalga Pseudo-nitzshia pungens: PP-07, PP-08, and PP-081. At a salinity of 24‰ the number of cells and PP contents in all P. pungens strains decreased after 1 day of exposure, compared to the control (salinity 32‰); with increasing exposure, these parameters restored to the control level. The number of cells and PP content decreased more significantly after 1 day of exposure to salinity lowered to 16‰. The number of dead cells was the highest at 8 and 4‰ after 1 day of exposure; by the end of the test the number of cells and PP contents were low. It was shown that the strains PP-07 and PP-081 were less tolerant to the effect of lowered salinity than the strain PP-08.

Key words: salinity, Pseudo-nitzshia pungens, cell number, chlorophyll a, carotenoids.