To investigate the status of fish resources within the Spinibarbu scaldwelli National Aquatic Germplasm Resources Reserve in Huyangxi River, Yongchun County, Fujian Province (referred to as the reserve), and assess the proliferation and release effects of in recent years, fishing methods such as gill nets and ground cage nets were employed to survey fish resources in the reserve in January, 2023. The survey revealed 28 fish species in the reserve during winter, comprising 3 orders, 7 families, and 25 genera. Within these, 16 genera and 18 species belonged to the Cypriniformes order, constituting 64.28% of total fish species. The order Siluriformes comprised 3 genera and 5 species, accounting for 17.86% of all species, while the Perciformes order consisted of 5 genera and 5 species, also representing 17.86% of all species. From January 7 to January 10, 2023, a total of 1 043 fish weighing 70 222.7 g were captured in the reserve. Dominant species included Coptodon zillii, Sarcocheilichthys nigripinnis, Abbottina elongata, and Distoechodon tumirostris. Among the captured fish, the proportion of S. caldwelli was relatively small, comprising 33 individuals weighted 6 438.0 g, accounting for 3.16% of the total catch by number and 9.27% by weight. Furthermore, the richness index, evenness index, and species diversity index of the reserve in winter were 2.770, 0.723, and 3.513, respectively. The proportion of alien fishes was relatively high, with main species including C. zillii, Oreochromis niloticus, and Sarotherodon galilaeus, indicating a significant invasion of alien fishes in lakes, oceans, and streams. Given that excessive reproduction of alien fishes may impede the survival and reproduction of local fish species, it is imperative to strengthen control measures against alien fishes and protect resources of S. caldwelli and other indigenous fish species.
