作者：Li, J., Lin, Z., Yu, J. et al.

Fish growth is closely related to environmental variables; however, how nutrient enrichment affects fish growth conditions remains unclear in subtropical polder rivers. We investigated the growth status of six fish species and nutrient concentrations at 40 sites in the subtropical polder rivers of the Lake Chaohu Basin, with the aim of evaluating how the fish condition factor (K) responds to nutrient enrichment across different feeding groups. We observed species-specific responses of growth conditions to nutrient enrichment. The omni-zooplanktivorous Hemiculter leucisculus and zooplanktivorous Toxabramis swinhonis exhibit better growth in nutrient-enriched rivers, with their K values showing a significant positive correlation with both total nitrogen (TN) and total phosphorus concentrations. However, the K values of the omni-benthivorous Carassius gibelio and Pseudobrama simoni exhibited no significant correlation with nutrient enrichment. Interestingly, the condition factor of the piscivorous Culter species also increased with rising TN levels. The growth patterns of H. leucisculus and C. gibelio were positive allometric, where the fish body weight increased at a faster rate than length. T. swinhonis and P. simoni showed isometric growth, in which both the body weight and length of them increased at approximately the same rates. These findings highlight the importance of considering fish functional traits (e.g., feeding guilds) when assessing the ecological impacts of eutrophication and provide insights for the management of subtropical polder river ecosystems under nutrient enrichment, such as predicting changes in fish community structure and developing targeted conservation strategies.

鱼类生长与环境变量密切相关，然而营养盐富集如何影响亚热带圩区河流鱼类的生长状况仍不清楚。研究在巢湖流域亚热带圩区河流的40个采样点调查了6种鱼类的生长状况与营养盐浓度，旨在评估不同食性类群鱼类的肥满度（K）对营养盐富集的响应。结果显示，生长状况对营养盐富集的响应存在种间特异性：杂食—浮游动物食性的䱗（Hemiculter leucisculus）与浮游动物食性的似鱎（Toxabramis swinhonis）在营养富集河流中生长更好，其K值与总氮（TN）、总磷（TP）浓度均呈显著正相关；而杂食—底栖动物食性的鲫（Carassius gibelio）与似刺鳊鮈（Pseudobrama simoni）的K值与营养盐富集无显著相关。有趣的是，肉食性的鲌属（Culter spp.）鱼类的肥满度也随TN浓度升高而增大。䱗与鲫的生长模式为正异速生长，即体重增长快于体长；似鱎与似刺鳊鮈则为等速生长，体重与体长以大致相同的速率增长。这些发现强调了在评估富营养化生态影响时考虑鱼类功能性状（如食性类群）的重要性，并为营养富集背景下亚热带圩区河流生态系统的管理提供了启示，例如预测鱼类群落结构的变化及制定有针对性的保护策略。

（来源：Ecology and Evolution 2026 Issue 4  DOI: 10.1002/ece3.73353）