Freshwater mussels of the tribe Gonideini (Bivalvia: Unionidae: Gonideinae) constitute one of the most taxonomically diverse groups and serve as keystone species in riverine and lacustrine ecosystems across East Asia. A new genus and species of Gonideini (Bivalvia: Unionidae) is described from Jiangxi, China, as Pseudopostolata angulagen. et sp. nov. based on an integrative analysis of shell morphology and molecular data. The validity of the new genus and species is supported by distinct conchological features: a short, rounded anterior; a long, wide posterior; a slightly downward-curved dorsal margin; and a distinctly obtuse angle at the center of the posterior margin. The multi-locus (COI + 16S rRNA + 28S rRNA) phylogeny showed that the species formed a monophyletic group in the tribe Gonideini of the subfamily Gonideinae. Pseudopostolata angulagen. et sp. nov. is identified as the sister group to a clade comprising the genera Postolata, Cosmopseudodon, Obovalis, Ptychorhynchus, Parvasolenaia, and Koreosolenaia. We emphasize the significant morphological convergence in freshwater mussels, particularly within Gonideini, highlighting the necessity of an integrated taxonomic approach for accurate generic classification of this group.

Understanding the impact mechanism of inter‐basin water transfer projects (IBWTs) on fish assemblages is critical for conserving aquatic ecosystems and managing water transfer. However, direct evidence of the impact mechanism of IBWTs on fish assemblages is absent. Fish assemblages in newly built terminal reservoirs originate and assemble with diverted individuals through water transfer in IBWTs, providing a valuable model for mechanistic research. This study sampled fish quarterly using a combination net in three terminal reservoirs along the Eastern Route of the South‐to‐North Water Transfer Project (ER‐SNWTP) from July 2021 to May 2022. We investigated assemblage composition and structure, calculated alpha and beta diversity indices, and analyzed the effects of environmental factors on fish assemblages. A total of 35 species were collected and indicated which species could be diverted accompanying water transfers along the ER‐SNWTP. Fish assemblages were dominated by eurytopic species, but showed clear seasonal differences. The distance from Dongping Lake, operation time of the reservoirs, and water quality affected diversity indices, composition and structure of the fish assemblages in the reservoirs. Fish assemblages in the terminal reservoirs were unstable and periodically disturbed by the water transfers of the ER‐SNWTP. Our results indicate that fish diverted by water transfer are likely to be the main cause of the impact of IBWTs on fish assemblages, and the distance and number of water transfers, and nutrient loading of diverted water are crucial factors affecting the impact of IBWTs. Our study provides a theoretical understanding of the ecological impacts of IBWTs by introducing fish and periodically disturbing fish assemblage through water transfer and highlights the necessity of scheming transfer programs to avoid overlapping with the spawning peaks of some fish with special guilds, such as small‐sized fish. In terminal reservoirs, the fish assemblages are not and may have no possibility to reach a stability like a natural one, and then their management should be oriented toward water quality regulation, such as rational harvesting and replenishment of biomanipulation fish to enhance their capacity for water quality regulation.

Surface subsidence caused by coal mining activities generates diverse wetland ecosystems. These newly formed wetlands exhibit distinct environmental characteristics due to variations in subsidence age, resulting in divergent biological communities. While species adapt to environmental changes through specific functional trait combinations, the response of aquatic community functional diversity to environmental gradients across chronosequences of mining subsidence wetlands remains unclear. This study investigated 13 coal mining subsidence wetlands (1–18 years) of macrozoobenthos in Jining, China. Through seasonal monitoring, we analyzed functional traits along with taxonomic and functional diversity patterns. Initial-stage wetlands were dominated by medium-sized (63.9%) and tegument-respiring taxa, whereas late-stage wetlands exhibited a shift toward large-sized (43.9%) and gill-respiring groups. Both species richness and functional richness declined over time, with taxonomic diversity demonstrating greater sensitivity to subsidence age. Seasonal community variability was more pronounced in initial-stage wetlands (1–4 years post-subsidence). Despite increasing habitat heterogeneity with subsidence age, functional redundancy maintains ecosystem stability. The shared origin and developmental trajectory of these wetlands may constrain functional divergence. Current research predominantly relies on traditional taxonomic metrics, whereas our findings emphasize functional trait analysis’s importance for ecosystem assessment, which provides a theoretical framework for ecological restoration and biodiversity conservation in post-subsidence wetlands.