While vivid colours in sexual signals can provide information on individual quality, vivid colours in interspecific signals have been interpreted mostly as indicating species identity and maximizing signal detection. Here we investigate if colour differences in an interspecific signal could also indicate relevant aspects of individual quality because, similarly to sexual signalling, in interspecific communication it could sometimes be advantageous to assess individual quality. An example is the interaction between client and cleaner species, where clients should benefit from assessing which individual cleaners provide good service. Since oxidative stress commonly influence condition-dependent colour signals, we oxidized the diet of cleaner wrasses (Labroides dimidiatus) in laboratory conditions to test if this affects their vivid blue skin colour and the quality of their cleaning service. Compared to controls, experimental cleaners decreased blue colour saturation after the oxidized diet treatment, decreased the quality of their cleaning service by performing less tactile stimulation and, although clients in the laboratory were de-parasitized, also tended to decrease the touching the client with the mouth. We used visual modelling, based on the spectral sensitivity of vision in various client species, to show that some client species can perceive these changes in cleaner blue colour saturation, while other client species are not. We suggest that, similarly to sexual signals, some vivid colours used in interspecific communication may convey information on aspects of individual quality that are relevant to heterospecifics.

中文翻译：

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更清洁的蓝调：视情况而定的颜色和更清洁的鱼类服务质量

虽然性信号中鲜艳的颜色可以提供关于个体质量的信息，但种间信号中的鲜艳颜色主要被解释为表明物种身份和最大化信号检测。在这里，我们调查了种间信号中的颜色差异是否也可以表明个体质量的相关方面，因为与性信号类似，在种间交流中，有时评估个体质量可能是有利的。一个例子是客户和清洁工物种之间的相互作用，客户应该从评估哪些清洁工提供良好服务中受益。由于氧化应激通常会影响与条件相关的颜色信号，我们在实验室条件下氧化了清洁濑鱼 (Labroides dimidiatus) 的食物，以测试这是否会影响它们鲜艳的蓝色皮肤和清洁服务的质量。与对照组相比，实验清洁工在氧化饮食处理后降低了蓝色饱和度，通过减少触觉刺激降低了他们的清洁服务质量，尽管实验室中的客户被去除了寄生虫，但也倾向于减少客户与他们的接触。嘴。我们使用视觉建模，基于各种客户物种的视觉光谱敏感性，表明一些客户物种可以感知更干净的蓝色饱和度的这些变化，而其他客户物种则不能。我们建议，类似于性信号，