ABSTRACT: The spatial dynamics of marine populations are shaped by habitat availability, environmental variability and individual interactions, particularly when multiple species share limited habitat such as patchy offshore reefs. The yellowmouth barracuda Sphyraena viridensis and the almaco jack Seriola rivoliana are the 2 most abundant bentho-pelagic reef predators in the Azores archipelago (central North Atlantic). They aggregate at shallow offshore seamounts, and largely share diet preferences, but very little is known about how habitat and resources are shared by these predators intra- and inter-specifically. Here we use long-term (over 3 yr) passive acoustic telemetry to investigate the patterns of activity, space use and associative behaviour at an isolated, small shallow seamount. By quantifying fine-scale spatiotemporal overlaps and performing null model randomization tests, we found evidence of non-random associations, mostly between conspecifics of both species, as well as shifts in diel and seasonal patterns of space occupancy. Both species were detected more often during spring, and appear to be more active during daytime, suggesting the absence of fine-scale temporal habitat partitioning. Additionally, we found evidence of size-dependent spatial behaviour in almaco jack, with similarly sized individuals co-occurring more often and larger specimens being more infrequently detected. This study quantitatively assesses individual associations using solely presence-absence data collected through passive acoustic telemetry, showing the potential of this approach in a broader application to a significant number of past and ongoing studies, even if many were not originally designed to study this important aspect of fish ecology.

中文翻译：

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浅海山上的两种掠食性礁鱼的种内和种间关联

摘要：海洋生物种群的空间动态取决于栖息地的可利用性，环境的变异性和个体之间的相互作用，尤其是当多种物种共享有限的栖息地（如斑驳的近海珊瑚礁）时。黄嘴梭子鱼Sphyraena viridensis和阿尔玛科杰克Seriola rivoliana是亚速尔群岛（北大西洋中部）中两个最丰富的底栖-上层珊瑚礁捕食者。它们聚集在浅海海山上，并且在饮食结构上基本相同，但是对于这些捕食者如何在种内和种间共享栖息地和资源知之甚少。在这里，我们使用长期（超过3年）的被动声学遥测技术来研究在一个孤立的小浅海山上的活动，空间使用和关联行为的模式。通过量化精细尺度的时空重叠并执行零模型随机检验，我们发现了非随机关联的证据，主要是两个物种的特定物种之间的关联，以及diel和空间占用的季节性变化。在春季，这两种物种的检测频率更高，并且在白天似乎更活跃，提示缺乏精细的临时生境分区。此外，我们发现了阿尔玛科杰克（Almaco jack）中大小相关的空间行为的证据，大小相似的个体更多地同时出现，而较大的标本也很少被发现。这项研究仅使用通过被动声遥测收集的在场数据来定量评估各个关联，从而表明该方法在更广泛的应用中可能存在的大量过去和正在进行的研究中，即使许多最初并非旨在研究这一重要方面的研究也是如此。鱼生态学。