Abstract：
Signal theory predicts organisms should evolve signals that are conspicuous to intended receivers in natural signalling environments. Cleaner shrimps remove ectoparasites from reef fish clients and many signal their intent to clean by whipping long, white antennae. As white is a reliably conspicuous colour in aquatic environments, we hypothesized that selection has acted to increase broad-spectrum antennal reflectance in cleaners. Using scanning electron microscopy, optical models and reflectance measurements, we found that the antennae in three obligate cleaner species from two families (Palaemonidae and Lysmatidae) had thick (∼6 µm) chitinous layers or densely packed high refractive index spheres (300-400 nm diameter), which models show increase reflectance (400-700 nm). Two facultative and non-cleaning species had no visible antennae ultrastructure beyond the chitinous exoskeleton. Antennae reflectance was significantly higher in obligate cleaners than in facultative and non-cleaning species. Our results suggest that some obligate cleaners may have evolved ultrastructures that increase the conspicuousness of their antennae as signals.
摘要：
信号理论预测，生物体应该进化出在自然信号环境中对预期接收者明显的信号。清洁虾从珊瑚礁鱼客户那里去除外寄生虫，许多人表示他们打算通过长时间鞭打来清洁，白色触角。由于白色在水生环境中是可靠的明显颜色，我们假设选择可以增加清洁剂中的广谱触角反射率。使用扫描电子显微镜，光学模型,和反射率测量，我们发现，来自两个科（Palaemonidae和Lysmatidae）的三个专性更清洁物种的触角具有厚（〜6µm）的几丁质层或密集堆积的高折射率球体（直径300-400nm），该模型显示增加反射率（400-700nm）。两种兼性和非清洁物种在几丁质外骨骼之外没有可见的触角超微结构。专性清洁剂的天线反射率明显高于兼性和非清洁物种。我们的结果表明，一些专性清洁剂可能已经进化出超微结构，从而增加了天线作为信号的显着性。
