Carryover effects of embryonic predation risk on larval growth, behaviour, morphology, and metamorphic traits of Euphlyctis cyanophlyctis

Early life experiences can have latent effects, which could manifest at a later stage of life history. Though the carryover effects of predation on the behaviour of prey are well-known, the integrative effects of predation on the growth, behaviour, and morphology of prey are less known. Hence, we used early (Gosner stages 10–14) and late (stages 15–19) embryonic stages of Euphlyctis cyanophlyctis to determine the carryover effects of predation risk on larval growth, behaviour, morphology, and metamorphic traits. Early and late embryonic stages were exposed to cues of predation risk to assess their antipredator responses later during larval life and at metamorphosis. The results show that embryonic exposure to cues of predation risk elicits antipredator behavioural responses towards kairomones of the dragonfly nymphs at the larval stage. Late embryonic stages exposed to cues of predation risk grew faster as larvae and displayed stronger antipredator responses than those exposed during early embryonic stages. Further, early embryonic stages facing cues of predation risk developed narrow bodies and longer tails as tadpoles. However, late embryonic stages facing cues of predation risk accrued greater body mass had narrow tails with greater tailfin heights and deeper tail muscles as tadpoles. The carryover effects of embryonic exposure to cues of predation risk were also apparent at metamorphosis. Embryos exposed during early stages metamorphosed earlier with larger body size. In contrast, embryos exposed to cues of predation risk at later stages metamorphosed earlier with larger length. Thus, the results of our study suggest that embryonic exposure to cues of larval predation induces latent behavioural and developmental carryover effects similar to those displayed by tadpoles facing predation risk.

Recognizing early life dangers may help animals to respond to such dangers later in their life. In this study, for the first time, we show the integrative effects of embryonic exposure to cues of predation risk on growth, behaviour, morphology and life history traits of larval life of the skipper frogs. In the skipper frogs, embryonic exposure to cues of predation risk induces behavioural and developmental effects similar to those shown by tadpoles facing predation risk.