Ziegelbecker Angelika, Remele Klaus, Pfeifhofer Hartwig W, Sefc Kristina M
Institute of Biology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria.
Institute of Biology, University of Graz, Schubertstraße 51, 8010 Graz, Austria.
Hydrobiologia. 2021;848(16):3683-3698. doi: 10.1007/s10750-020-04354-3. Epub 2020 Aug 18.
The famously diverse body coloration of cichlid fish serves communicative functions in mating and social interactions including competition for resources. Here, we examined the effects of a color pattern trait-the width of a yellow bar on a black body-on territorial competition in males and females of a color variant ("Ikola") of the Lake Tanganyika cichlid . First, measuring integumentary carotenoid concentrations in the yellow and black body regions, we established that wider yellow bars require more carotenoids allocated to body coloration. However, we also detected high carotenoid concentrations in the black body regions (> 100 µg/g fresh skin), raising questions about the function of non-displayed integumentary carotenoids. Behavioral experiments showed that fish with wider bars were quicker to explore an unfamiliar area of the tank. In experiments including presentations of fish dummies, the bar width of 'territorial' dummies had no effect on the latency time which test fish took to intrude into the dummies' territories. However, male test fish performed fewer aggressive acts against wide-barred than against narrow-barred dummy competitors. Our results suggest that intimidation by wide bars as well as correlations between bar width and explorative behavior may contribute to mediating success in territorial "Ikola".
丽鱼科鱼类以其多样的体色而闻名，这种体色在交配和包括资源竞争在内的社会互动中发挥着交流功能。在此，我们研究了一种颜色模式特征——黑色身体上黄色条纹的宽度——对坦噶尼喀湖丽鱼科鱼类一个颜色变种（“伊科拉”）的雄性和雌性领地竞争的影响。首先，通过测量黄色和黑色身体区域的体表类胡萝卜素浓度，我们确定较宽的黄色条纹需要更多分配给体色的类胡萝卜素。然而，我们还在黑色身体区域检测到高浓度的类胡萝卜素（>100μg/g鲜皮），这引发了关于未用于展示的体表类胡萝卜素功能的疑问。行为实验表明，条纹较宽的鱼更快地探索水族箱中不熟悉的区域。在包括展示鱼类模型的实验中，“领地”模型的条纹宽度对测试鱼侵入模型领地的潜伏时间没有影响。然而，雄性测试鱼对宽条纹模型竞争者的攻击行为比对窄条纹模型竞争者少。我们的结果表明，宽条纹的威慑作用以及条纹宽度与探索行为之间的相关性可能有助于调解“伊科拉”在领地竞争中的成功。
