Unusually high levels of eicosatetraenoic, eicosapentaenoic, and docosahexaenoic fatty acids in Palestinian freshwater sponges.

The fatty acid compositioin of three freshwater sponges-Ephydatia syriaca, Nudospongilla sp., and Cortispongilla barroisi-were studied. Twenty principal fatty acids, and unusually high levels of eicosatetraenoic (5,8,11,14-20:4 up to 10.1% of the total acid mixture), eicosapentaenoic (5,8,11,14,17-20:5 up to 11.6%), and docosahexaenoic acids (4,7,10,13,16,19-22:6 up to 11.8%) were detected. The only demospongic acid found was 5,9,17-hexacosatrienoic acid (1.8-3.7%).