Total Amounts and Ratios of n-3 and n-6 Fatty Acids of Fish Eggs in Response to Parasite Infection in Wild Fish

Maternal allocation of fatty acids to eggs has profound consequences for egg viability, larval survival, and therefore recruitment of the population. Teleost eggs are rich in polyunsaturated fatty acids, particularly EPA and DHA, which are vital for normal embryo development. Parasites rob the host of energy ultimately affecting maternal diet and body stores, which are the main sources of fatty acids in eggs. General linear models were used to explore the effects of parasite infection on the percentage and ratios of DHA, EPA, PAL, and ARA in fish eggs collected from female common snook Centropomus undecimalis in spawning aggregations on the east coast of Florida. Ninety-eight percent (n = 39) of the study population was infected with either live or dead parasites. Egg fatty acids were affected by biological, spatial, and infection factors. However, we demonstrate that these relationships are not necessarily linear and can be positive or negative. Among the fatty acids examined, parasite infection had the strongest effect on EPA, and as a consequence, in ratios containing EPA. Considering the deleterious effects on larval survival from EPA deficiency, and antagonistic functions in relation to other fatty acids, this study suggests that infection with parasites contributes to recruitment variation.