Discussion
The transmission of environmentally-induced epigenetic modifications to the offspring could have important implications for evolution (Richards et al. 2017; Verhoeven et al. 2016) but has proven challenging to study in natural populations, due to the confounding effects of genotype-by-environment interactions (Berbel-Filho et al. 2019; Herman & Sultan 2016) and also to the unequal paternal and maternal contributions to epigenetic states (Soubry et al. 2014). By rearing the self-fertilising mangrove killifish K. marmoratus under controlled environmental conditions, we identified significant physiological (basal metabolic rate and cortisol levels), behavioural (neophobia, activity) and epigenetic differences among parents reared under two different levels of environmental enrichment, which influenced the offspring phenotypes.