Introduced non-native fishes have the potential to substantially alter aquatic ecology in the introduced range through competition and predation. The Alaska blackfish (Dallia pectoralis) is a freshwater fish endemic to Chukotka and Alaska north of the Alaska Range (Beringia); the species was introduced outside of its native range to the Cook Inlet Basin of Alaska in the 1950s, where it has since become widespread. Here we characterize the diet of Alaska blackfish at three Cook Inlet Basin sites, including a lake, a stream, and a wetland. We analyze stomach plus esophageal contents to assess potential impacts on native species via competition or predation. Alaska blackfish in the Cook Inlet Basin consume a wide range of prey, with major prey consisting of epiphytic/benthic dipteran larvae, gastropods, and ostracods. Diets of the introduced populations of Alaska blackfish are similar in composition to those of native juvenile salmonids and stickleback. Thus, Alaska blackfish may affect native fish populations via competition. Fish ranked third in prey importance for both lake and stream blackfish diets but were of minor importance for wetland blackfish.

中文翻译：

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阿拉斯加库克湾盆地引进的阿拉斯加黑鱼（Dallia pectoralis）种群的营养生态学

引入的非本地鱼类有可能通过竞争和捕食来显着改变引入范围内的水生生态。阿拉斯加黑鱼（Dallia pectoralis）是楚科奇和阿拉斯加以北阿拉斯加山脉（白令）的特有淡水鱼；该物种于 1950 年代从其原生范围之外引入阿拉斯加的库克湾盆地，并在那里广泛传播。在这里，我们描述了三个库克湾盆地的阿拉斯加黑鱼的饮食特征，包括湖泊、溪流和湿地。我们分析胃和食道内容物，以评估通过竞争或捕食对本地物种的潜在影响。库克湾盆地中的阿拉斯加黑鱼捕食范围广泛的猎物，主要猎物包括附生/底栖双翅目幼虫、腹足动物和介形动物。引入的阿拉斯加黑鱼种群的饮食在组成上与本地幼年鲑鱼和刺鱼相似。因此，阿拉斯加黑鱼可能会通过竞争影响本地鱼类种群。鱼类在湖泊和溪流黑鱼饮食中的猎物重要性方面排名第三，但对湿地黑鱼来说重要性不高。