ABSTRACT Like mono-species fish groups, formation of mixed-species assemblages is likely driven by trophic influences and interspecific behavioural traits. Our aim was to identify how sympatric estuarine species of differing phenotypes form mixed-species group associations, and to identify changes to group structure of fish that migrate between mono- and mixed-species groups. We used sympatric yellow-eyed mullet (Aldrichetta forsteri), kahawai (Arripis trutta), and Australian snapper (Chrysophrys auratus), representing different phenotypes for the mixed-species group, and yellow-eyed mullet for the mono- and mixed-species comparison. Group formation and structure was quantified in predator and foraging treatment groups. We used previous research in mono-species yellow-eyed mullet to compare behavioural plasticity with the current study. Our novel results suggest similar behavioural traits in mono- and mixed-species fish groups have beneficially co-evolved and importantly, behavioural plasticity is necessary for migration between groups. Overall, our observations highlight key behavioural responses associated with mixed-species fish formations in estuarine ecosystems.

中文翻译：

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当近邻成为好朋友时：形成单一和混合物种群体的同域鱼类行为特征的可塑性

摘要 像单一物种的鱼群一样，混合物种组合的形成很可能是由营养影响和种间行为特征驱动的。我们的目的是确定不同表型的同域河口物种如何形成混合物种群关联，并确定在单一和混合物种群之间迁移的鱼类群结构的变化。我们使用同域黄眼鲻鱼 (Aldrichetta forsteri)、kahawai (Arripis trutta) 和澳大利亚鲷鱼 (Chrysophrys auratus)，代表混合物种组的不同表型，使用黄眼鲻鱼进行单一和混合物种比较. 在捕食者和觅食处理组中量化组的形成和结构。我们使用先前对单一物种黄眼鲻鱼的研究来比较当前研究的行为可塑性。我们的新结果表明，单一和混合物种鱼类群体中相似的行为特征已经有益地共同进化，重要的是，行为可塑性对于群体之间的迁移是必要的。总体而言，我们的观察突出了与河口生态系统中混合物种鱼类形成相关的关键行为反应。