European catfish Silurus glanis is a large non-native opportunistic predator able to develop hunting strategy in response to newly available prey where it has been introduced. Migrating spawning anadromous prey such as allis shad Alosa alosa could represent this available and energy-rich food resource. Here, we report an impressive catfish hunting behavior on shad spawning act in one of the main spawning grounds in Europe (Garonne River, Southwest France). Shad spawning act consists of at least one male and one female swimming side by side, trashing the water surface with their tail which, therefore, produces a splashing noise audible from the river bank. The catfish hunting behavior on shad spawning act was studied, at night, during spring months, using both auditory and video survey. Simultaneously, catfish individuals were fishing to analyze their stomach content. Catfish disturbed 12% of the 1024 nocturnal spawning acts we heard, and this proportion increased to 37% among the 129 spawning acts when estimated with low-light camera recording. Stomach content analyses on 251 large catfish individuals (body length > 128 cm) caught in the same river stretch revealed shad represented 88.5% of identified prey items in catfish diet. This work demonstrates that European catfish predation must be considered as a significant factor of mortality of allis shad. In a context of the extension of the European catfish range area in western and southern European freshwaters, this new trophic impact, with other ones previously described for salmon or lamprey, has to be considered in European conservation plans of anadromous species.

欧洲cat鱼Silurus glanis是一种大型的非本土机会性捕食者，能够针对引入的新猎物制定狩猎策略。迁移产卵的无敌猎物，例如allis shad Alosa alosa可以代表这种可用的且能量丰富的食品资源。在这里，我们报告了在欧洲的一个主要产卵场（法国西南部加洛讷河）的sha鱼产卵行为中令人印象深刻的hunting鱼狩猎行为。d鱼的产卵过程包括至少一头雄性和一头雌性并排游泳，用尾巴将水面倒掉，从而产生从河岸可听到的飞溅声。利用听觉和视频调查研究了在春季春季晚上，sha鱼产卵行为下hunting鱼的狩猎行为。同时，cat鱼个体在钓鱼以分析其胃的含量。we鱼扰乱了我们听到的1024次夜间产卵行为中的12％，如果用低照度相机记录进行估算，这一比例增加到了129次产卵行为中的37％。对在同一条河中捕获的251只large鱼个体（体长> 128厘米）的胃液含量分析表明，sha鱼占cat鱼饮食中确定的猎物的88.5％。这项工作表明，欧洲cat鱼的捕食必须被视为是大葱鱼死亡率的重要因素。在欧洲cat鱼在西欧和南欧淡水范围扩大的背景下，这种新的营养影响，以及先前对鲑鱼或七lamp鳗所描述的其他营养影响，必须在欧洲无水生物保护计划中予以考虑。这项工作表明，欧洲cat鱼的捕食必须被视为是大葱鱼死亡率的重要因素。在欧洲cat鱼在西欧和南欧淡水范围扩大的背景下，这种新的营养影响，以及先前对鲑鱼或七lamp鳗所描述的其他营养影响，必须在欧洲无水生物保护计划中予以考虑。这项工作表明，欧洲cat鱼的捕食必须被视为是大葱鱼死亡率的重要因素。在欧洲cat鱼在西欧和南欧淡水范围扩大的背景下，这种新的营养影响，以及先前对鲑鱼或七lamp鳗所描述的其他营养影响，必须在欧洲无水生物保护计划中予以考虑。