Balshine Sigal, Wong Marian Y L, Reddon Adam R
Department of Psychology, Neuroscience, & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada.
School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
Behav Processes. 2017 Aug;141(Pt 2):152-160. doi: 10.1016/j.beproc.2017.01.001. Epub 2017 Jan 3.
Even closely related and ecologically similar cichlid species of Lake Tanganyika exhibit an impressive diversity of social systems, and therefore these fishes offer an excellent opportunity to examine the evolution of social behaviour. Sophisticated social relationships are thought to have evolved via a building block design where more fundamental social behaviours and cognitive processes have been combined, incrementally modified, and elaborated over time. Here, we studied two of these putative social building blocks in two closely related species of cichlids: Neolamprologus pulcher, a group-living species, and Telmatochromis temporalis, a non-grouping species. Otherwise well matched in ecology, this pair of species provide an excellent comparison point to understand how behavioural processes may have been modified in relation to the evolution of sociality. Using social assays in both the laboratory and in the field, we explored each species' motivation to interact with conspecifics, and each species' conflict resolution tactics. We found that individuals of the group living species, N. pulcher, displayed higher social motivation and were more likely to produce submission displays than were individuals of the non-grouping species, T. temporalis. We argue that the motivation to interact with conspecifics is a necessary prerequisite for the emergence of group living, and that the use of submission reduces the costs of conflict and facilitates the maintenance of close social proximity. These results suggest that social motivation and conflict resolution tactics are associated with social complexity, and that these behavioural traits may be functionally significant in the evolution and maintenance of sociality.
即使是坦噶尼喀湖亲缘关系密切且生态相似的丽鱼科鱼类，其社会系统也展现出令人印象深刻的多样性，因此这些鱼类为研究社会行为的进化提供了绝佳机会。复杂的社会关系被认为是通过一种积木式设计进化而来的，在这种设计中，更基本的社会行为和认知过程随着时间的推移被组合、逐步修改和完善。在这里，我们研究了两种亲缘关系密切的丽鱼科鱼类中的两种假定社会行为模块：群居的新亮丽鲷和非群居的颞叶丽鲷。这两个物种在生态方面其他条件良好匹配，为理解行为过程如何随着社会性的进化而发生改变提供了绝佳的比较点。通过在实验室和野外进行社会行为测定，我们探究了每个物种与同种个体互动的动机以及每个物种的冲突解决策略。我们发现，群居物种新亮丽鲷的个体比非群居物种颞叶丽鲷的个体表现出更高的社会动机，并且更有可能做出顺从展示。我们认为，与同种个体互动的动机是群居出现的必要前提，而使用顺从行为可以降低冲突成本，并有助于维持紧密的社会距离。这些结果表明，社会动机和冲突解决策略与社会复杂性相关，并且这些行为特征在社会性的进化和维持中可能具有重要的功能意义。
