FATTY-ACID DISTRIBUTION AMONG SOME RED ALGAL MACROPHYTES

Macrophytic members of the Rhodophyta, which were grown under controlled conditions, were analyzed for their fatty acid distribution. Significant differences were found between some species of the Gelidiales and Gracilariales. Two dominant polyunsaturated fatty acids of the 20 carbon chain group, 20:4-omega-6 and 20:5-omega-3, were found in all the Gelidiales species, whereas only 20:4-omega-6 was found in the Gracilariales species. An inverse relationship between the content of these two polyunsaturated fatty acids in Gelidiales species and among the tao groups of species are reported and discussed. All other fatty acid characteristics were more or less similar in these two orders. We cannot draw any solid conclusion about the relationship between Gracilariopsis cf. lemaneiformis (formerly Gracilaria lemaneiformis) and the genus Gracilaria, since our results (the existence of 20:4-omega-6 and 20:5-omega-3 in Gracilariopsis) contradict results found by other researchers. The diverse growth conditions of photon flux density and temperature caused some differences in the distribution Of the fatty acids in each species. These differences could not explain the different results in similar species reported in the literature.