The establishment probability of introduced alien fish can be context dependent, varying according to factors including propagule pressure and biotic resistance. The influence of nutrient enrichment on establishment outcomes of alien fishes is uncertain, yet this is a common anthropogenic stressor of many freshwaters. Here, the small-bodied alien topmouth gudgeon Pseudorasbora parva was used in mesocosms to experimentally test how a gradient of nutrient enrichment affected their growth rates, recruitment and trophic ecology. A ‘Control’ represented ambient, mesotrophic conditions, while treatments covered three levels of nutrient enrichment: low (eutrophic), medium (hypertrophic) and high (very hypertrophic). Each mesocosm was seeded with 6 mature P. parva (equal sex ratio) at the start of their reproductive season. After 100 days, length increments of the adult fish were significantly elevated in the low treatment, and these fish had also produced significantly higher numbers of 0+ fish compared to all other treatments. The trophic niche width of the mature fish was substantially higher in the control than the treatments, but this did not appear to confer any advantages to them in somatic growth rate or reproductive output. These results suggest that the nutrient status of receiving waters can have substantial impacts on the outcomes of fish introductions, where eutrophic conditions can assist the rapid population establishment of some alien species.

引入的外来鱼的建立概率可能取决于环境，并根据包括繁殖压力和生物抗性在内的因素而变化。营养素丰富度对外来鱼类建立结果的影响尚不确定，但这是许多淡水常见的人为压力源。在这里，小体外星人topmouth udge头假单胞菌（Pseudorasbora parva）被用于介观试验，以实验性地测试养分浓度梯度如何影响它们的生长速度，补充和营养生态。“对照”代表周围的中营养状况，而处理涵盖了营养富集的三个水平：低（富营养），中（肥大）和高（非常肥​​大）。每个mesocosm播种有6个成熟的P. parva（性别平等）在生育季节开始时。100天后，成年鱼的长度增加在低处理中显着增加，并且与所有其他处理相比，这些鱼还产生了数量明显多于0+的鱼。对照中成熟鱼的营养位宽度明显高于处理，但这似乎并未赋予它们体细胞生长速率或繁殖产量任何优势。这些结果表明，接受水域的营养状况可能对鱼类引进的结果产生重大影响，而富营养化的条件可以帮助某些外来物种迅速建立种群。