Tracing Transgenerational Plasticity Through Ova Fatty Acid Biomarkers in Giant Kōkopu (Galaxias argenteus)

Abstract

Broodstock management has traditionally focused on heritable traits and diet-induced gamete quality. However, the potential of transgenerational plasticity (TP) underscores the importance of understanding adaptive trait transfer in aquaculture, where the sustainability of production can be hampered by mortality arising from disease and stress. Notably, the role of fatty acids (FAs) as important biomarkers is an untapped area of TP research with implications for the management of new aquaculture species. We assessed TP in Giant Kōkopu (Galaxias argenteus) by comparing the ova FA profiles of broodstock across five captive generations; wild-caught, F1, and three successive F2s. Our study revealed intergenerational shifts in ova FA profiles. We encountered a significant decline in C18:1 (n-9) (Oleic Acid, OLA) and C20:4 (n-6) (Arachidonic acid, ARA), and an increase in C16:0 (Palmitic acid, PAL) from wild-caught to captive-bred broodstock. These shifts reveal that latter generations of captive-bred G. argenteus are reducing the provision of FAs associated with stress (OLA) and lower reproductive success (ARA), while increasing those linked to improved immune response (PAL), signalling a significant adaptation to captivity. Our findings help elucidate the theoretical understanding of TP through the use of FAs as biomarkers, providing practical insight for broodstock management.