Reproductive control via the threat of eviction in the clown anemonefish

In social groups, high reproductive skew is predicted to arise when the reproductive output of a group is limited, and dominant individuals can suppress subordinate reproductive efforts. Reproductive suppression is often assumed to occur via overt aggression or the threat of eviction. It is unclear, however, whether the threat of eviction alone is sufficient to induce reproductive restraint by subordinates.Here,we test two assumptions of the restraint model of reproductive skew by investigating whether resource limitation generates reproductive competition and whether the threat of eviction leads to reproductive restraint in the clown anemonefish Amphiprion percula. First, we use a feeding experiment to test whether reproduction is resource limited, which would create an incentive for the dominant pair to suppress subordinate reproduction. We showthat the number of eggs laid increased in the population over the study period, but the per cent increase in fed groups was more than twice th...

在社会群体中，当群体的繁殖产出受限，且优势个体能够抑制从属个体的繁殖活动时，往往会出现较高的繁殖偏倚（reproductive skew）。繁殖抑制（reproductive suppression）通常被认为是通过公开的攻击行为或驱逐威胁来实现的。然而目前尚不清楚，仅靠驱逐威胁是否足以促使从属个体产生繁殖克制行为。本研究以公子小丑鱼（Amphiprion percula）为研究对象，通过探究资源限制是否会引发繁殖竞争，以及驱逐威胁是否会促使从属个体产生繁殖克制，来检验繁殖偏倚克制模型的两项假设。首先，我们通过喂食实验（feeding experiment）检验繁殖过程是否受资源限制——若繁殖受资源限制，则优势配对会产生抑制从属个体繁殖的激励动机。我们发现，研究期间种群的产卵总量有所上升，而投喂组的产卵量增幅则是其两倍多……