Summary: | Fatty acid composition of eggs affects development, growth, and ecological performance of fish embryos and larvae, with potential consequences for recruitment success. Essential fatty acids in eggs derive from the maternal diet, and the time between ingestion and deposition in eggs is ecologically important but unknown. We examined the dynamics of diet-egg transfer of arachidonic acid (ARA) in the batch-spawning fish, red drum (Sciaenops ocellatus), by measuring ARA concentrations in eggs after a single diet shift and during a period of irregular variations in diet. ARA concentrations in eggs changed within 2-16 days of a diet shift. The rate of change was proportional to the magnitude of the shift, with no evidence of equilibration. These results are not consistent with eggs being assembled entirely from accumulated body stores. The immediate source of ARA in eggs appears to be the recent diet. We propose that batch spawning produces rapid diet-egg transfer of ARA because it removes large amounts of fatty acids from the body and prevents equilibration. The immediacy of the diet-egg connection suggests that spawning migration combined with short-interval batch spawning may have evolved to take advantage of nutrients critical for offspring survival that are available at the spawning site. Arachidonic acid content of individual spawns of eggs from captive red drum after a diet-shift.Data were manually entered into a Microsoft Excel spreadsheet then imported into Systat statistical software for analysis and graphing. Data extracted from Systat to create this file. Variable names and descriptions are provided in ReadMe.txt.Diet-shift data.xlsRegression statistics for changes in arachidonic acid concentration of red drum eggs over time after a diet shift. Regression statistics are estimates of initial concentration and incorporation rate of arachidonic acid in eggs.Data were derived from linear regressions computed by Systat statistical software and exported to create this file. Variable names and descriptions are ...
|