Negotiations over parental care: a test of alternative hypotheses in the clown anemonefish

Abstract

In species with biparental care, conflict arises over how much each parent provides to their offspring because both parents benefit from shifting the burden of care to the other. Here, we tested alternative hypotheses for how parents will negotiate offspring care using a wild population of clownfish (Amphiprion percula). We experimentally handicapped parents by fin-clipping the female in 23 groups, the male in 23 groups, and neither parent in 23 groups and measured changes in indicators of female, male, and pair effort in response to handicapping. First, we found that handicapping resulted in a decrease in the number of eggs laid by fin-clipped females and a decrease in the amount of parental care by fin-clipped males. Second, contrary to predictions, female effort did not change in response to the male being handicapped, or vice versa. Finally, the number of embryos that matured to hatching, an indicator of pair effort, was not influenced by the manipulation, suggesting that although the handicap was effective, clownfish do not face the predicted “cost to conflict” when one parent is handicapped. Together, these results test the generality of theoretical predictions and uncover novel questions about whether and how negotiations operate in systems where interests are aligned.

Behavioural repertoire and the effect of male removal in a geotrupid beetle with parental care

“…Furthermore, we found no significant difference in care behaviour between females paired with a resident or a new mate or being without a mate. Females may not modify their care behaviour noticeably depending on the identity of their partner, indicating that there might be a strict division of tasks between the sexes (Barbasch et al., 2021; Henshaw et al., 2019). Our study also demonstrates that the behavioural repertoires of the sexes appear to be very similar in the two populations we studied.…”

Evolution, Development and Ecology of Anemonefishes

“…While the theory is sound, a test of a series of negotiation models in A. percula revealed that no current models fully explain whether and how anemonefish parents negotiate (Barbasch et al 2021). When one parent was experimentally handicapped via fin clipping, the other parent seemingly did not respond: males tended just as much when the female was handicapped and females tended just as much when the male was handicapped.…”

“…An alternative hypothesis is that female tending has more to do with monitoring clutch development, in preparation for their involvement on the night of hatching (Pacaro 2022). Another alternative is that female tending is indicative of her monitoring her partner's efforts, as part of a negotiation over levels of care (Barbasch et al 2021). Finally, it's also plausible that selection for male care is strong and selection against low levels of female care is weak, meaning that female care may be a case of intergender hitchhiking (Clint et al 2012) in these sex-changing fish.…”