Dynamics of diet-egg transfer of fatty acids in the teleost fish, red drum (Sciaenops ocellatus).

Eggs of marine organisms are increasingly being recognized as important components of marine food webs. The degree to which egg fatty acid profiles reflect maternal diet fatty acid profiles, and therefore the value of fatty acids in eggs as trophic biomarkers, depends on the species' reproductive strategy and the extent of modification of ingested fatty acids. We measured the dynamics of transfer of recently ingested fatty acids to spawned eggs in a batch-spawning teleost, red drum (Sciaenops ocellatus). Results of 21 diet-shift experiments, from which the fatty acid profiles of the diets and eggs were compared, showed that 15 of 27 fatty acids measured (one saturated, two monounsaturated and 12 polyunsaturated fatty acids) in eggs were correlated with their levels in the recent diet, and the rate of incorporation into eggs was proportional to the magnitude of the diet shift. Large shifts in diet might occur naturally during spawning migrations or when prey communities vary over time. Results of this study indicate that fatty acids in red drum eggs can be useful for studying adult diet and exploring trophic linkages in marine systems. This article is part of the theme issue 'The next horizons for lipids as 'trophic biomarkers': evidence and significance of consumer modification of dietary fatty acids'.