Abstract:

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.

Key words: freshwater fishes, species diversity, taxonomy, Ganjiang River