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.