Amézquita Adolfo, Ramos Óscar, González Mabel Cristina, Rodríguez Camilo, Medina Iliana, Simões Pedro Ivo, Lima Albertina Pimentel
Department of Biological Sciences, Universidad de los Andes, Cra 1 #18A-10, Bogotá, 111711, Colombia.
Laboratório de Sistemática de Vertebrados, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga 6681, Prédio 40, sala 110, Porto Alegre CEP, 90619-900, Brasil.
Evolution. 2017 Apr;71(4):1039-1050. doi: 10.1111/evo.13170. Epub 2017 Feb 15.
Predation risk is allegedly reduced in Batesian and Müllerian mimics, because their coloration resembles the conspicuous coloration of unpalatable prey. The efficacy of mimicry is thought to be affected by variation in the unpalatability of prey, the conspicuousness of the signals, and the visual system of predators that see them. Many frog species exhibit small colorful patches contrasting against an otherwise dark body. By measuring toxicity and color reflectance in a geographically variable frog species and the syntopic toxic species, we tested whether unpalatability was correlated with between-species color resemblance and whether resemblance was highest for the most conspicuous components of coloration pattern. Heterospecific resemblance in colorful patches was highest between species at the same locality, but unrelated to concomitant variation in toxicity. Surprisingly, resemblance was lower for the conspicuous femoral patches compared to the inconspicuous dorsum. By building visual models, we further tested whether resemblance was affected by the visual system of model predators. As predicted, mimic-model resemblance was higher under the visual system of simulated predators compared to no visual system at all. Our results indicate that femoral patches are aposematic signals and support a role of mimicry in driving phenotypic divergence or mimetic radiation between localities.
据称，在贝氏拟态和缪勒拟态中，捕食风险会降低，因为它们的体色与不可口猎物的醒目体色相似。人们认为拟态的效果会受到猎物不可口程度的变化、信号的醒目程度以及看到它们的捕食者的视觉系统的影响。许多蛙类物种都有色彩鲜艳的小斑块，与深色的身体形成对比。通过测量一种地理分布可变的蛙类物种以及同域有毒物种的毒性和颜色反射率，我们测试了不可口性是否与种间颜色相似性相关，以及相似性对于体色模式中最醒目的成分是否最高。在同一地点的物种之间，色彩斑块的异种相似性最高，但与毒性的伴随变化无关。令人惊讶的是，与不显眼的背部相比，显眼的股部斑块的相似性更低。通过构建视觉模型，我们进一步测试了相似性是否受到模型捕食者视觉系统的影响。正如预测的那样，与完全没有视觉系统相比，在模拟捕食者的视觉系统下，拟态与模型的相似性更高。我们的结果表明，股部斑块是警戒信号，并支持拟态在推动不同地点之间的表型分化或拟态辐射中所起的作用。
