The Pike Killifish Belonesox belizanus is an established nonnative fish species that was first documented in south Florida, USA, in 1957 and secondarily in Tampa Bay tidal tributaries in 1994. Decreased abundance and altered size structure in small-bodied fish populations have been linked to Pike Killifish introductions in both of these regions. Increases in the range and abundance of Pike Killifish in Tampa Bay waters and overlap in habitat usage with juvenile Common Snook Centropomus undecimalis have led to concerns about potential predation on early juvenile (≤125 mm TL) Common Snook. We investigated predation of Pike Killifish on early juvenile Common Snook through experimental predation trials and stomach content analysis of Pike Killifish from field sampling. During predation trials, fasted, large adult (≥104 mm TL) Pike Killifish were presented with one of three prey taxa: Common Snook (N = 139), Pike Killifish conspecifics (N = 68), and Eastern Mosquitofish Gambusia holbrooki (N = 68); the fate of the prey was recorded after 48 h. Common Snook with both intact (N = 70) and clipped (N = 69) anal spines were used as prey to investigate whether this structure deterred predation by Pike Killifish. Predation trials indicated that Pike Killifish were capable of consuming early juvenile Common Snook up to 60 mm TL and that the anal spine did not deter predation by Pike Killifish. Stomach content analysis was performed on 422 wild-caught Pike Killifish from Tampa Bay tidal tributaries where early juvenile Common Snook co-occurred, but no Common Snook remains were found in their diets. Combined, these studies indicate that despite being able to consume relatively large early juvenile Common Snook, Pike Killifish do not exert predatory pressure on early juvenile Common Snook in the wild and therefore do not appear to be a factor contributing to population-level effects or delayed recovery in Common Snook populations.

中文翻译：

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非本地梭子鱼不会对普通斯努克幼鱼施加捕食压力

Pike Killifish Belonesox belizanus是一种成熟的非本地鱼类，于 1957 年首次在美国佛罗里达州南部被记录，其次于 1994 年在坦帕湾潮汐支流中被记录。小型鱼类种群的丰度减少和大小结构改变与梭鱼有关这两个地区的鳉鱼引进。坦帕湾水域 Pike Killifish 的范围和丰度增加，栖息地与普通 Snook Centropomus undecimalis幼鱼重叠引起了人们对早期幼鱼（≤125 毫米 TL）常见斯努克的潜在捕食的担忧。我们通过实验性捕食试验和野外取样对梭子鱼的胃内容物分析，调查了梭子鱼对早期幼鱼普通 Snook 的捕食。在捕食试验期间，禁食的大型成年梭子鱼（≥104 毫米 TL）与三种猎物分类群中的一种一起呈现：普通鳉（N  = 139）、梭子鱼同种（N  = 68）和东部蚊鱼Gambusia holbrooki（N  = 68); 48 小时后记录猎物的命运。具有完整 ( N  = 70) 和剪裁 ( N = 69）肛门刺被用作猎物来研究这种结构是否阻止了梭鱼的捕食。捕食试验表明，梭子鱼能够捕食长达 60 毫米 TL 的早期幼鱼普通 Snook，并且肛门棘并不能阻止梭子鱼的捕食。对来自坦帕湾潮汐支流的 422 条野生捕捞的梭子鱼进行了胃含量分析，在这些支流中，早期幼鱼共同出现，但在它们的饮食中没有发现普通史努克残留物。综合起来，这些研究表明，尽管能够吃掉相对较大的早期幼年普通 Snook，但梭子鱼不会对野外的早期幼年普通 Snook 施加捕食压力，因此似乎不是导致种群水平影响或延迟的因素Common Snook 种群的恢复。