Occurrence of cis-9,10-methylenehexadecanoic and cis-9,10-methyleneoctadecanoic acids in the lipids of immature and mature Fundulus heteroclitus (L.), and in roe

Abstract

1. 1. Analysis of saturated fatty acids in the mummichog Fundulus heteroclitus (L.) by argentation chromatography and open-tubular gas-liquid chromatography detected cyclopropanoid fatty acids as well as all of the anticipated saturated fatty acids, including a variety of branched-chain saturated fatty acids previously found in fish. 2. 2. Cyclopropanoid fatty acids were identified in juveniles, male and female bodies, and roe. When the levels of these acids in eviscerated male and female bodies were compared with roe, roe had the highest concentration, followed by female and then male fish. 3. 3. Whole immature mummichog had almost twice the proportion of cyclopropanoid fatty acids found in whole mature male fish. 4. 4. The cyclic acids probably originate indirectly in the diet of the mummichog. This consists mainly of invertebrates probably consuming bacteria associated with plant detritus. 5. 5. The Atlantic silversides Menidia menidia collected from the same habitat had lower proportions of odd-chain methyl-branched fatty acids, and lower proportions of cyclopropanoid fatty acids, indicating differences in sources of dietary fatty acids.