Mohamed Zein Alabdein Nassar¹ , Hamdy Ramadan Galal² , Hanan Mohamed Khairy¹ , Sara Hamdy Rashedy¹

1. National Institute of Oceanography and Fisheries, Hydrobiology Lab, Egypt
2. Botany Department, Faculty of Science, South Valley University, Egypt
Author    Correspondence author
International Journal of Marine Science, 2016, Vol. 6, No. 1   doi: 10.5376/ijms.2016.06.0001
Received: 28 Sep., 2015    Accepted: 19 Nov., 2015    Published: 01 Jan., 2016

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 Nassar M. Z., Galal H. R. M., Khairy H. M., and Rashedy S. H., 2016, Biological Responses of the Marine Diatom Chaetoceros simplex Ostenfeld to Different Treatments of Phosphate and Nitrate, International Journal of Marine Science, Vol.6, No.01 1-8 (doi: 10.5376/ijms.2016.06.0001)

Chaetoceros simplex Ostenfeld of marine diatoms was isolated and purified from the sub-surface waters of the north-western part of the Red Sea, Egypt (Hurgada). The isolated grown cells are exposed to different concentrations of nitrate and phosphate to estimate their effects on the growth and some metabolic activities of the organism. In general, the results indicated thatconcentrations of 100 μM nitrate and 5μM phosphate stimulated the algal growth by 60% and 32%, respectively in the 8^th day of culture. While, the values of 300 μM nitrate and 50 μM phosphate exhibited a decrease in the algal growth by 44% and 49%, respectively as compared with the control culture. The photosynthetic pigments (Chl-a, Chl-c and Carotenoids), total soluble proteins and carbohydrates of Chaetoceros simplex followed a similar pattern of change to that of growth in response to different treatments of nitrate and phosphate. While, the addition of different treatments of nitrate and phosphate to F/2 medium decreased the total lipids of C. simplex.  Statistical analysis of the data indicated that 5 μM phosphates and 50 μM nitrates were the highly significant and most effective concentrations that positively affect most of different metabolic activities of Chaetoceros simplex. Thus, Chaetoceros simplex culture could be used as larval feed or other purposes cultured using 50 μM nitrate and 5μM phosphate.

Chaetoceros simplex; Nitrate; Phosphate; Metabolic activities