关键词: 鱼类资源, 群落结构, 多样性指数, 时空分异

Abstract

Aims: Lugu Lake, a significant plateau deep-water lake in Southwest China, has not had its fish community reported in recent years. 

Methods: This study was conducted to investigate the current status of fish communities in Lugu Lake through four field surveys carried out in spring (May) and autumn (October) of 2023 and 2024. Redundancy analysis (RDA) and clustering methods were employed to elucidate the driving effects of environmental factors on the spatiotemporal patterns of fish community structure. 

Results: A total of 14 fish species were identified, categorized into 2 orders, 4 families, with Cypriniformes being the predominant order (85.71%). The only indigenous fish species recorded was Misgurnus anguillicaudatus, while 13 exotic fish species were recorded, constituting 92.86% of the total species, with Carassius auratus and Pseudorasbora parva being the most abundant. RDA revealed that fish community structure was influenced by NO₃^‒-N and pH in spring, and by NO₃^‒-N and total nitrogen in autumn. The abundance-biomass comparison curve (ABC) showed that the biomass curve in autumn was significantly higher than the abundance curve, presenting an “autumn stable–spring substable state” pattern. 

Conclusion: To address the challenges faced by the fish community in Lugu Lake, such as the decline of indigenous species and the prevalence of exotic species, we recommend focusing on conserving indigenous fish, enhancing pollution control, regulating the release of exotic species, and establishing a comprehensive long-term monitoring program.

Key words: fish resources, community structure, diversity index, temporal and spatial variation