The role of colour patterns in a social context: causes and consequences of interspecific variation in anemonefishes

在动物分类群中，颜色图案具有显著的多样性，然而，我们对这些颜色图案的进化的理解仍然没有得到解决。研究集中在一些模式物种上，如果蝇、老鼠和斑马鱼，而海洋鱼类的代表性很低。此外，大多数关于颜色模式功能的研究都探讨了自然选择（如伪装、警告）和性选择（如配偶选择）的背景，而社会选择（如维持群体稳定）很少被考虑。在社会群体中，社会地位和个人身份的信号对于避免代价高昂的互动和维持合作可能很重要。该项目旨在深入了解颜色图案的这些社会功能，并促进我们对动物王国颜色图案进化的理解。海葵鱼（Amphiprion spp.）为解决这些问题提供了一个有希望的模型。它们具有复杂的等级群体结构，在这种结构中，维持群体稳定的社会信号是有益的。它们的基本生态是已知的，它们附着在海葵宿主上，便于反复观察和现场实验。海葵鱼在不同物种的颜色模式、生态和社会结构上也表现出显著的多样性。研究这些物种差异将有助于探索形成社会结构和颜色图案多样性的进化过程。这将促进我们对复杂社会群体的形成和维持以及在更广泛的分类群中颜色模式的进化的理解。这个项目的目标是了解海葵鱼的颜色模式的社会功能，以及颜色模式对鱼类社会结构的影响。本研究的目的、方法和假设如下：1)通过实验检验颜色图案在社会地位信号中的作用。我们将不同颜色的大小匹配的个体引入有繁殖配对的海葵宿主，并确定对它们的攻击程度。我们预测，具有更发达的颜色图案的个体将受到更多的攻击，通过颜色图案表明社会地位的信号。2)实验检验色彩图案在个体识别中的作用。我们将把熟悉的和不熟悉的大小匹配的个体介绍给海葵鱼群体，在一个只允许视觉线索转移的设置中，并确定对它们的攻击程度。我们预测熟悉的个体会受到较少的群体成员的攻击，这表明个体通过颜色图案来识别。3)量化社会环境下色彩图案发展的可塑性。首先，我们将把定居者作为支配者或从属者介绍给海葵宿主。我们预测，为了避免来自优势群体的攻击，从属移民会比优势移民发展出更慢的颜色模式。其次，我们将从海葵鱼群中移除个体，以允许提升到主导地位，并评估颜色模式的变化。我们预测，与那些没有改变社会地位的人相比，地位上升的人在颜色图案上的变化会更大。4)量化安菲普里昂属的社会系统和颜色模式的变化。使用三种两栖类（A. percula， A. perideraia和A. clarkii），我们将拍摄个体并记录行为，以量化颜色图案特征和社会网络矩阵。我们预测由于生态和系统发育的差异，社会系统和颜色模式在物种之间的变化，社会系统和颜色模式将共同变化。例如，显示身份信号和个体识别的标志模式的物种可能会有更多的合作，更少的冲突。

There is remarkable diversity in colour patterns across animal taxa, however, our understanding of the evolution of these colour patterns remains unsolved. Research has focused on a few model species, such as fruit flies, mice and zebrafish, and marine fishes are highly underrepresented. In addition, the majority of studies investigating the functions of colour patterns have explored contexts of natural selection (e.g., camouflage, aposematism) and sexual selection (e.g., mate choice), with social selection (e.g., maintaining group stability) rarely being considered. In social groups, signalling of social status and individual identity can be important to avoid costly interactions and maintain cooperation. This project aims to provide insight into these social functions of colour patterns and advance our understanding of the evolution of colour patterns across the animal kingdom.Anemonefishes (Amphiprion spp.) provide a promising model to address such questions. They have complex hierarchical group structures, in which social signalling for maintaining group stability would be beneficial. Their basic ecology is known and they are site attached to anemone hosts, facilitating repeated observations and in-situ experiments. Anemonefish also display remarkable diversity in colour patterns across species, as well as variation in ecology and social structures. Investigating these species differences will allow exploration of the evolutionary processes that shape diversity in both social structures and colour patterns. This will advance our understanding of the formation and maintenance of complex social groups and the evolution of colour patterns across a wider range of taxa. The goal of this project is to understanding the social functions of colour patterns in anemonefishes and the causes and consequences of colour patterns in regards to the fishes' social structures. The objectives, approach and hypotheses are as follows:1) Experimentally test the function of colour patterns in social status signalling. We will introduce size-matched individuals with different colourations to anemone hosts with breeding pairs and determine the level of aggression towards them. We predict that individuals with more developed colour patterns will receive more aggression from dominants, indicating social status signalling via colour patterns.2) Experimentally test the function of colour patterns in individual recognition. We will introduce familiar and unfamiliar size-matched individuals to anemonefish groups, in a set-up that only allows transfer of visual cues, and determine level of aggression towards them. We predict that familiar individuals will receive less aggression from group members, indicating individual recognition via colour patterns.3) Quantify the plasticity in colour pattern development in response to social context. Firstly, we will introduce settlers to anemone hosts as dominants or subordinates. We predict that subordinate settlers will develop colour patterns slower than dominant settlers to avoid aggression from dominants. Secondly, we will remove individuals from anemonefish groups to allow ascension to dominant status and assess changes to colour patterns. We predict that individuals ascending status will show greater change in colour patterns compared to those not changing social status.4) Quantify variation in social systems and colour patterns across the Amphiprion genus. Using three Amphiprion species (A. percula, A. perideraion and A. clarkii), we will photograph individuals and record behaviours in order to quantify colour pattern characteristics and social network matrices. We predict variation in social systems and colour patterns across species due to differences in ecology and phylogeny and that social systems and colour patterns will co-vary. For example, species displaying hallmark patterns of status signalling and individual recognition will likely have more cooperation, less conflict.