1. The delimitation of conservation units may be supported by information on compositional (taxonomic), functional, and phylogenetic diversity of a given locality or region. In this context, systematic conservation planning and key biodiversity areas are promising approaches for biodiversity protection.
2. Factors such as species representativeness and exclusivity may be used to identify geographical distribution patterns and select relevant areas for conservation at a local scale.
3. This study aims to identify areas with rare and restricted fish species in mountain streams in Southern Brazil, using a method that unites ecological and biogeographical approaches.
4. Seven river basins and 152 mountain streams in Southern Brazil were sampled to obtain data on the occurrence and abundance of 115 fish species. The rarity status of each species was determined and endemicity analysis was used to find areas of restricted species (ARS) with three cell sizes.
5. Using larger cells, continuous areas were identified and supported by a higher proportion of rare fish species. Using smaller cells, discontinuous areas were identified within each of the river basins, where rare and endemic fish species occur. Most of the smaller areas relevant for protecting fish fauna were located outside of conservation units.
6. Fundamental areas were selected for the protection of fish species in mountain streams in Southern Brazil. Both the method proposed and the areas with rare and restricted fish species identified may be used to support systematic conservation planning and to delimit new priority areas for conservation.

中文翻译：

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在巴西南部山区溪流中选择稀有和受限鱼类的区域

1. 保护单位的划定可以得到有关特定地点或区域的组成（分类）、功能和系统发育多样性的信息的支持。在此背景下，系统的保护规划和重点生物多样性区域是生物多样性保护的有希望的方法。
2. 物种代表性和排他性等因素可用于确定地理分布模式并在当地范围内选择相关区域进行保护。
3. 本研究旨在使用生态和生物地理方法相结合的方法，确定巴西南部山区溪流中稀有和受限鱼类的区域。
4. 对巴西南部的 7 个河流流域和 152 条山间溪流进行了采样，以获取有关 115 种鱼类的发生率和丰度的数据。确定每个物种的稀有状态，并使用地方性分析找到具有三种细胞大小的受限物种 (ARS) 区域。
5. 使用更大的单元格，连续区域被识别并由更高比例的稀有鱼类提供支持。使用较小的单元格，在每个河流流域内确定了不连续的区域，其中出现了稀有和地方性鱼类。大多数与保护鱼类区系相关的较小区域位于保护单位之外。
6. 选择了基本区域来保护巴西南部山区溪流中的鱼类。提议的方法和确定的稀有和受限鱼类物种的区域都可用于支持系统的保护规划和划定新的优先保护区域。