Fish fauna from the Paranapanema River basin, Brazil

Abstract: The Paranapanema River is an important, extensively explored tributary of the Upper Paraná River basin. The fish fauna of the Paranapanema River has been investigated since the 1990s; however, no study has characterized the richness of fish species throughout the basin, including the main channel of the river, marginal lagoons, its tributaries, and sub-tributaries. Thus, we performed a review with 90 independent studies conducted at the upper, middle, and lower sections of the basin. We recorded 225 species, of which 165 were native, and 60 were non-native. We found that 77% of the species within the basin are composed by Siluriformes and Characiformes. Cichliformes had a significant number of non-native species established in impoundment sections of the basin. Incidence-Based Estimators (Bootstrap and Chao 2) demonstrated that the richness of native species is still underestimated. Some native (e.g., Hypostomus ancistroides) and non-native species (e.g., Plagioscion squamosissimus) are widely distributed in the basin, while others had a more restricted distribution. Among the registered species, the family Bryconidae had the highest number of representatives with threatened conservation status. In addition, we observed that the Capivara Reservoir and its tributaries were the most sampled regions, with the majority of studies performed in the Lower Paranapanema basin. The species richness recorded in large tributaries, such as Tibagi, Cinzas, Congonhas, and Pirapó rivers is critical for maintaining the fish fauna in the Paranapanema River. Our contribution may be used to support management actions and conservation strategies, as well as to indicate regions in the basin that need to be better inventoried.

摘要：巴拉那帕内马河（Paranapanema River）是巴拉那河上游流域一处重要且被广泛开发的支流。自20世纪90年代以来，学界已对巴拉那帕内马河的鱼类区系展开调查，但尚无研究系统刻画该流域全范围——包括干流、边缘泻湖、支流及次级支流——的鱼类物种丰富度。为此，我们对该流域上、中、下游河段开展的90项独立研究进行了综述。本次综述共记录到225种鱼类，其中本土种165种，外来种60种。研究发现，该流域内77%的物种均隶属于鲇形目（Siluriformes）与脂鲤目（Characiformes）；慈鲷目（Cichliformes）在流域的拦河坝蓄水河段中拥有大量已成功定殖的外来物种。基于发生率估计法（Incidence-Based Estimators，含自助法（Bootstrap）与Chao 2估计量）的分析结果表明，本土物种丰富度仍存在低估情况。部分本土物种（如钩突护胸鲶（Hypostomus ancistroides））与外来物种（如南美银鲈（Plagioscion squamosissimus））在流域内广布，另有部分物种分布范围较为局限。在所记录的物种中，布氏脂鲤科（Bryconidae）的受威胁物种数量最多。此外，我们发现卡皮瓦拉水库（Capivara Reservoir）及其支流为采样强度最高的区域，多数研究均在巴拉那帕内马河下游流域开展。诸如蒂巴吉河（Tibagi）、辛扎斯河（Cinzas）、孔戈尼亚斯河（Congonhas）以及皮拉波河（Pirapó）等大型支流所记录的物种丰富度，对维持巴拉那帕内马河的鱼类区系至关重要。本研究成果可为流域管理行动与保护策略提供支撑，同时可指明该流域内亟需开展更全面本底调查的区域。