The effects of broodstock generation on ova fatty acid profile in Giant Kokopu Galaxias argenteus

Abstract

ABSTRACT The ability of different broodstock generations to provision lipids to their gametes is often overlooked in aquacultured freshwater fish. In this study we investigated the ability of two generations (F1 & F2) of Giant Kokopu (Galaxias argenteus) to provision fatty acids into their eggs. Here we show that eggs of captive-bred females (F2) displayed different relative fatty acid concentrations compared with eggs of females bred from wild fish (F1). F2 generation eggs showed significantly lower total mono unsaturated fatty acids (MUFA) concentration, predominantly through lower C18:1(n−9) Oleic acid, and higher total poly unsaturated fatty acids (PUFA) concentration, predominantly through higher 22:6(n−3) docosahexaenoic acid [DHA]. Furthermore, Oleic to n−3 fatty acid ratio, and Oleic to DHA ratio, both declined significantly from F1 to F2 generation. Our results suggest an elevated capacity of F2 females to provision better ratios of essential fatty acids during reproduction, most likely due to a transgenerational adaptive response, either to the fed diet or to a predictable laboratory environment. The findings of this study have important implications for aquaculture management in new captive freshwater species, particularly in aiding identification of more adapted broodstock generations.