Potential for employing the distribution of anomalous non-methylene-interrupted dienoic fatty acids in several marine invertebrates as part of food web studies.

A group of homologous, nonmethylene-interrupted dienoic fatty acids (NMID) recently reported in oysters has been found in several other shellfish species and also in other marine phyla. The distribution of most other "normal" fatty acids among several species of shellfish is basically similar but mantle lipids from two other molluscan species, both squid, differ radically. The squid mantle fatty acids do not include NMID, suggesting that in molluscs NMID may accumula-e primarily in filter-feeders or herbovores. The distribution of these anomalous fatty acid components in higher species suggests that they reflect invertebrates in the diet and are biochemically inert.