赣江鱼类物种更新名录

赣江是长江的主要支流之一, 淡水鱼类多样性极其丰富, 但是目前对于该河流的鱼类多样性还未有充分的了解。本研究于2016年9月至2017年8月对赣江鱼类进行了实地调查, 结合历史文献资料并参考最新的分类学成果, 更新了赣江淡水鱼类名录。结果表明, 赣江共有淡水鱼类180种, 隶属于12目31科93属。其中, 土著鱼类174种, 外来鱼类6种。赣江鱼类以鲤形目为主; 鲤科种类最多, 其次是鲿科。更新的物种名录中, 包含23个新记录土著种, 其中有5个未被描述的新种; 有36个历史资料记载的种类被剔除出物种名录; 25个物种发生了分类地位的变更。此外, 本次调查有28种鱼类未采集到, 说明这些鱼类的种群数量正在急剧下降, 而这些鱼类分别属于洄游性、流水性和产漂流性卵等独特生态类型, 说明赣江鱼类多样性受到了严重的人为干扰。本研究所给出的赣江鱼类的更新物种名录, 可为今后的赣江鱼类多样性保护提供理论基础。

An updated species checklist of freshwater fishes from the Ganjiang River

Aims: The Ganjiang River is one of the major tributaries flowing into the Yangtze River basin. This area harbors a high variety of freshwater fish, but its fish diversity is not yet fully understood. To this end, seasonal field surveys of the fishes in this river were conducted from September 2016 to August 2017.
Methods: Due to the complexity of the habitat types, numerous sampling methods were employed to collect the fish specimens. Battery-powered backpack electro-fishing was used in small, shallow, or navigable streams to capture fish, and a single pass electro-fishing method was used from bottom to top; the distance and time of operation depended on the situation. For streams that could be waded, gill nets, cast nets, and cages were used to collect fish specimens (we prepared gill nets and cages of various sizes for each habitat type). Also, fish were collected from the markets in the study area to ensure that sufficient specimens were available for study. Based on the survey results and historical records and the current taxonomic revisions made for relevant fish groups, an updated checklist of the freshwater fishes of the Ganjiang River was created.
Results: This updated checklist of the freshwater fishes in the Ganjiang River included a total of 180 species belonging to 12 orders, 31 families, and 93 genera. Among them, 174 species are indigenous and six are aliens. Cypriniformes dominate the fish fauna of this river. Cyprinidae had the highest number of species, followed by the Bagridae. There are 23 newly recorded species, 5 of which were previously undescribed. Twenty-five of the valid species had nomenclatural changes, 36 historically recorded species were excluded. Twenty-eight documented fish species that have unique ecological preferences such as migratory species, fast running water dwellers, and pelagic drifting eggs-releasing species were not collected during these field surveys.
Conclusion: The species diversity of freshwater fish from the Ganjiang River is not only still in the stage of exploration and discovery, but also under severe threat from anthropogenic interferences. The updated checklist presented here undoubtedly provides baseline information that will aid efforts to conserve the biodiversity of the Ganjiang River in the future.