1. Habitat fragmentation and loss threaten freshwater biodiversity worldwide. Habitats that are essential as fish spawning and nursery sites are critical, and must be identified for conservation purposes. Littoral zones within Patagonian lakes, especially shallow vegetated areas, represent important areas for the Creole perch, Percichthys trucha.
2. Spawning behaviour has been little studied, so it is not known whether these movements are performed in groups. A particular area of a deep lake in northern Patagonia was studied to identify the environmental conditions under which spawning occurs, and to analyse spawning aggregation behaviour in relation to the lunar cycle.
3. To identify spawning sites, spawning occurrence time, and the environmental parameters that determine it, fish capture data were analysed. Underwater cameras were also set up at three depth strata in the shallow zone to detect spawning aggregation behaviour. Aggregation was scored as the greatest number of individuals present in a single frame, and the number present per depth stratum. The relationship between the lunar cycle and Creole perch abundance by depth was then determined.
4. This is the first visual record of a spawning bed and the spawning aggregation behaviour of Creole perch in Patagonian lakes. The abundance of mature Creole perch in the shallow strata during the austral spring suggests that vegetated areas constitute spawning sites. Spawning aggregation takes place at a shallow depth 2 days before the full moon.
5. As the reproductive behaviours of Creole perch are important phenomena in the life history of the species, the results of this study have important implications for conservation and management.

中文翻译：

---

克里奥尔鲈鱼的产卵聚集行为，Percichthys trucha（Percichthyidae）：保护的目标物种

1. 栖息地破碎化和丧失威胁着全世界的淡水生物多样性。作为鱼类产卵和育苗地点必不可少的栖息地至关重要，必须为保护目的确定。巴塔哥尼亚湖泊内的沿岸带，尤其是浅植被区，是克里奥尔鲈鱼Percichthys trucha 的重要区域。
2. 产卵行为的研究很少，因此不知道这些运动是否成群进行。研究了巴塔哥尼亚北部深湖的一个特定区域，以确定产卵发生的环境条件，并分析与月球周期相关的产卵聚集行为。
3. 为了确定产卵地点、产卵发生时间和决定它的环境参数，对鱼类捕获数据进行了分析。在浅水区的三个深度地层还设置了水下摄像机，以检测产卵聚集行为。聚合被评分为单个帧中存在的最大个体数量，以及每个深度层中存在的数量。然后确定了月球周期与深度的克里奥尔鲈鱼丰度之间的关系。
4. 这是巴塔哥尼亚湖泊中克里奥尔鲈鱼产卵床和产卵聚集行为的首次视觉记录。南方春季浅层中大量成熟的克里奥尔鲈鱼表明植被区构成了产卵地点。产卵聚集发生在满月前 2 天的浅层。
5. 由于克里奥尔鲈鱼的繁殖行为是该物种生活史中的重要现象，因此本研究结果对保护和管理具有重要意义。