Department of Biology, University of Neuchâtel, Emile-Argand, 11, 2000 Neuchâtel, Switzerland.
Fishery Research Unit, LAZBW, Argenweg 50/1, 88085 Langenargen, Germany.
J Exp Biol. 2020 Dec 29;223(Pt 24):jeb231613. doi: 10.1242/jeb.231613.
In many mutualisms, benefits in the form of food are exchanged for services such as transport or protection. In the marine cleaning mutualism, a variety of 'client' reef fishes offer 'cleaner' fish access to food in the form of their ectoparasites, where parasite removal supposedly protects the clients. Yet, the health benefits individual clients obtain in the long term from repeated ectoparasite removal remain relatively unknown. Here, we tested whether long-term reduced access to cleaning services alters indicators of health status such as body condition, immunity and the steroids cortisol and testosterone in four client damselfish species , , and To do so, we took advantage of a long-term experimental project in which several small reefs around Lizard Island (Great Barrier Reef, Australia) have been maintained cleaner-free since the year 2000, while control reefs had their cleaner presence continuously monitored. We found that the four damselfish species from reef sites without cleaners for 13 years had lower body condition than fish from reefs with cleaners. However, immunity measurements and cortisol and testosterone levels did not differ between experimental groups. Our findings suggest that clients use the energetic benefits derived from long-term access to cleaning services to selectively increase body condition, rather than altering hormonal or immune system functions.
在许多互利共生关系中，以食物形式提供的好处被用来换取运输或保护等服务。在海洋清洁互利共生关系中，各种“客户”礁鱼为“清洁鱼”提供食物，即它们的外寄生虫，去除寄生虫据称可以保护客户。然而，客户从反复去除外寄生虫中获得的长期健康益处仍知之甚少。在这里，我们测试了长期减少清洁服务的机会是否会改变健康状况的指标，如身体状况、免疫力以及皮质醇和睾酮等类固醇在四种客户雀鲷物种、、和 中。为此，我们利用了一个长期的实验项目，自 2000 年以来，蜥蜴岛（大堡礁，澳大利亚）周围的几个小珊瑚礁一直没有清洁工，而对照珊瑚礁则不断监测其清洁工的存在。我们发现，在没有清洁工的珊瑚礁上生活了 13 年的四种雀鲷的身体状况比有清洁工的珊瑚礁上的鱼差。然而，实验组之间的免疫测量和皮质醇和睾酮水平没有差异。我们的研究结果表明，客户利用长期获得清洁服务的能量益处来选择性地增加身体状况，而不是改变激素或免疫系统功能。
