Dick Jaimie T A, Elwood Robert W
School of Biological Sciences, Queen's University of Belfast, Belfast BT9 7BL, Northern Ireland, UK.
Biol Lett. 2006 Dec 22;2(4):501-4. doi: 10.1098/rsbl.2006.0512.
Models of parent-offspring conflict concerning levels of caregiving centre on conflict resolution by offspring control, compromise or offspring 'honest signalling' that parents use to maximize their own fitness. Recent empirical studies on motivational control of parental feeding of offspring are interpreted as supporting the latter model. Here, we examine parental care in an amphipod, Crangonyx pseudogracilis, which directs care to embryos in a brood pouch. Embryo removal and transplantation elucidated causal factors that determine levels of caregiving. In the short-term, females with all embryos removed reduced care activities, but partial embryo removal did not affect caregiving, evidence of 'unshared' parental care. In the long-term, females with all embryos removed ceased care. Thus, females have a maternal state that is maintained by stimuli from offspring. Transplantation of early/late stage embryos among females originally carrying early/late stage embryos revealed that stimuli from embryos indicate their age-dependent needs, but only modify caregiving within the constraints of a changing endogenous maternal state. Thus, we demonstrate that mothers and offspring share motivational control of care. However, we highlight the inappropriate use of motivational data in reaching conclusions about the resolution of parent-offspring conflict.
关于照料水平的亲子冲突模型主要围绕后代控制、妥协或后代“诚实信号”来解决冲突展开，父母利用这些方式来最大化自身的适应性。近期关于亲代对后代喂养的动机控制的实证研究被解释为支持后一种模型。在此，我们研究了一种双足节肢动物——伪细钩虾的亲代照料行为，该物种会将照料行为指向育儿袋中的胚胎。胚胎移除和移植揭示了决定照料水平的因果因素。短期内，所有胚胎都被移除的雌性减少了照料活动，但部分胚胎被移除的情况并未影响照料行为，这是“非共享”亲代照料的证据。从长期来看，所有胚胎都被移除的雌性停止了照料。因此，雌性具有一种由后代刺激维持的母性状态。在最初携带早期/晚期胚胎的雌性之间进行早期/晚期胚胎移植，结果表明胚胎的刺激表明了它们随年龄变化的需求，但仅在不断变化的内源性母性状态的限制范围内改变照料行为。因此，我们证明了母亲和后代共同控制照料行为的动机。然而，我们强调在得出关于亲子冲突解决的结论时不恰当地使用了动机数据。
