Effect of Salinity on the Growth and Fatty Acid Composition of Ulva pertusa Kjellman (Chlorophyta)

Abstract

Changes in the specific growth rate and fatty acid composition of Ulva pertusa were observed at various salinities (20, 25, 3O, 35 and 40‰), in a completely randomized laboratory experiment. Specific growth rates were highest at 30 and 35‰. Moisture content did not significantly vary between salinity treatments. Crude lipid contents of thalli at salinities above 30‰ were 30-70% higher than at lower salinities (e.g., at 30‰, crude lipid was 1.47% of fresh weight or 5.59% of dry weight; at 25‰, crude lipid was 0.42% of fresh weight, or 1.93% of dry weight). High salinity increased the overall levels of the n-3 major polyunsaturated fatty acids (16:4n-3, 18:3n-3 and 18:4n-3), whereas, low salinity increased the levels of the fatty acids, 16:0, 18:1, 20:3 and the essential fatty acid 20:5