Gingins Simon, Roche Dominique G, Bshary Redouan
Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland.
Proc Biol Sci. 2017 Apr 26;284(1853). doi: 10.1098/rspb.2016.2469.
Predatory reef fishes regularly visit mutualistic cleaner fish () to get their ectoparasites removed but show no interest in eating them. The concept of compensated trait loss posits that characters can be lost if a mutualistic relationship reduces the need for a given trait. Thus, selective pressures on escape performance might have relaxed in due to its privileged relationship with predators. However, the cost of failing to escape a predatory strike is extreme even if predation events on cleaners are exceptionally rare. Additionally, cleaners must escape from non-predatory clients that regularly punish them for eating mucus instead of parasites. Therefore, strong escape capabilities might instead be maintained in cleaner fish because they must be able to flee when in close proximity to predators or dissatisfied clients. We compared the fast-start escape performance of with that of five closely related wrasse species and found that the mutualistic relationship that cleaners entertain with predators has not led to reduced escape performance. Instead, conflicts in cleaning interactions appear to have maintained selective pressures on this trait, suggesting that compensated trait loss might only evolve in cases of high interdependence between mutualistic partners that are not tempted to cheat.
肉食性珊瑚礁鱼类经常拜访互利共生的清洁鱼（ ）以清除体表寄生虫，但对吃掉它们没有兴趣。补偿性性状丧失的概念认为，如果互利共生关系减少了对特定性状的需求，那么相关性状可能会丧失。因此，由于清洁鱼与捕食者之间的特殊关系，对其逃逸能力的选择压力可能已经放松。然而，即使清洁鱼遭受捕食的事件极为罕见，未能逃脱捕食攻击的代价也是极其高昂的。此外，清洁鱼必须逃离那些经常因它们吃掉黏液而非寄生虫而惩罚它们的非捕食性客户。因此，清洁鱼可能反而保持了强大的逃逸能力，因为当它们靠近捕食者或不满的客户时，必须能够迅速逃离。我们将清洁鱼的快速启动逃逸能力与五种亲缘关系密切的隆头鱼物种进行了比较，发现清洁鱼与捕食者之间的互利共生关系并未导致其逃逸能力下降。相反，清洁互动中的冲突似乎对这一性状保持了选择压力，这表明补偿性性状丧失可能只会在互利共生伙伴之间高度相互依赖且不存在欺骗诱惑的情况下才会演化。
