The fatty acid composition of tropical marine algae of the genus Halimeda (Chlorophyta)

The fatty acid composition of the tropical genus Halimeda (Halimediaceae, B ryopsidales), represented by the six Caribbean species Halimeda opuntia (Li nnaeus) Lamouroux, Halimeda goreauii (W. R. Taylor), Halimeda copiosa Gorea u et Graham, Halimeda monile (Ellis et Solander) Lamouroux, Halimeda simula ns Howe, and Halimeda incrassata (Ellis) Lamouroux, is reported for the fir st time. The six species possessed similar fatty acid compositions with som e exceptions. Principal fatty acids were 14:0, 16.0, 18:2 (n-6), and 18:3 ( n-3), followed by 20:4 (n-6), and 20:5 (n-3). These species contained only 16:3 and no 16:4 as the key C-16 polyunsaturated fatty acid. In the species of Halimeda studied the 18:1 (n-7) /18:1 (n-9) ratio was less than I, with the exception of H. monile where it was close to I. The very long-chain fa tty acids tetracosanoic acid (24:0), pentacosanoic acid (25:0), and hexacos anoic acid (26:0), were identified in H. copiosa, H. monile, and H. incrass ata. The Delta 5,9 fatty acids 18:2 (n-9) and 20:2 (n-11) (H. monile) plus 26:2 (n-17) (H. copiosa) were identified in algae for the first time.