Ichthyofauna from floodplain lakes of Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), lower rio Purus

Abstract: The ichthyofauna of the rio Purus has been little investigated, especially in its lower portion, characterized by diverse aquatic environments, especially in flooded areas. We inventoried the ichthyofauna of floodplain lakes with different management efforts in Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), which represent important resource for commercial fishing in North region, in the first illustrated inventory of the fish fauna from lower rio Purus. We surveyed 20 lakes, classified as open access (eight lakes) and protected (12 lakes) during 2009 low water levels. A total of 2,299 individuals were collected, represented by seven orders, 25 families and 74 species. Characiformes was the most representative order in number of species and families, followed by Siluriformes, Cichliformes, Gymnotiformes, Clupeiformes, and Osteoglossiformes. Most abundant and frequent species were Pygocentrus nattereri, Triportheus angulatus, Serrasalmus sp. "2n=58", Pterygoplichthys gibbiceps, and Osteoglossum bicirrhosum. Protected lakes presented higher species richness compared to open access lakes. Similarly, protected lakes possessed 26 species occurring exclusively, with emphasis on Colossoma macropomum, an important species for fisheries due to its commercial importance. We added 44 new records of fish species for the lower rio Purus. Our results indicate the potential efficiency of zoning systems of open access and protected lakes established by local population and ruled by RDS-PP for fisheries management. Therefore, we strongly suggest its maintenance for conservation of ichthyofauna of floodplain lakes of lower rio Purus.

摘要：普鲁斯河（Rio Purus）的鱼类区系鲜有研究，其下游区域更是如此——该区域以多样的水生环境为特征，尤以洪泛区为甚。本研究针对普鲁斯河下游开展首次鱼类区系图解式编目，对皮阿加苏-普鲁斯可持续发展保护区（Reserva de Desenvolvimento Sustentável Piagaçu-Purus，RDS-PP）内不同管理模式下的洪泛湖进行调查，这些湖泊是巴西北部地区商业捕捞的重要资源。2009年枯水期，我们共调查了20个湖泊，其中开放式捕捞区（8个）与保护区（12个）各占一定比例。本次调查共采集到2299尾个体，隶属于7个目、25个科及74个物种。脂鲤目（Characiformes）是物种数与科数均最多的类群，其次为鲇形目（Siluriformes）、慈鲷目（Cichliformes）、裸背电鳗目（Gymnotiformes）、鲱形目（Clupeiformes）与骨舌鱼目（Osteoglossiformes）。优势且常见的物种包括纳氏臀点脂鲤（Pygocentrus nattereri）、棱角三角胸脂鲤（Triportheus angulatus）、锯脂鲤未定种“Serrasalmus sp. "2n=58"”、驼背翼甲鲶（Pterygoplichthys gibbiceps）与双须骨舌鱼（Osteoglossum bicirrhosum）。相较于开放式捕捞湖，保护区内的物种丰富度更高；且保护区内独有26个物种，其中以巨脂鲤（Colossoma macropomum）为代表——该物种因商业价值极高，是重要的捕捞对象。本次调查为普鲁斯河下游新增了44个鱼类物种记录。研究结果表明，由当地社群设立、受RDS-PP管理的开放式捕捞区与保护区分区制度，在渔业管理中具备潜在高效性。因此，我们强烈建议维持该分区制度，以保护普鲁斯河下游洪泛湖的鱼类区系。