National Institute of Water and Atmospheric Research Limited, Wellington, New Zealand.
PLoS One. 2010 Oct 27;5(10):e13647. doi: 10.1371/journal.pone.0013647.
Ling and hake are tertiary consumers, and as a result both may have an important structuring role in marine communities. The diets of 2064 ling and 913 hake from Chatham Rise, New Zealand, were determined from examination of stomach contents. Ling was a benthic generalist, and hake a demersal piscivore. The diet of ling was characterised by benthic crustaceans, mainly Munida gracilis and Metanephrops challengeri, and demersal fishes, mainly Macrourids and scavenged offal from fishing vessels. The diet of hake was characterised by teleost fishes, mainly macrourids and merlucciids. Multivariate analyses using distance-based linear models found the most important predictors of diet variability were depth, fish length, and vessel type (whether the sample was collected from a commercial or research vessel) for ling, and fish length and vessel type for hake. There was no interspecific predation between ling and hake, and resource competition was largely restricted to macrourid prey, although the dominant macrourid species predated by ling and hake were different. Cluster analysis of average diet of intraspecific groups of ling and hake confirmed the persistent diet separation. Although size is a central factor in determining ecological processes, similar sized ling and hake had distinctly different foraging ecology, and therefore could influence the ecosystem in different ways, and be unequally affected by ecosystem fluctuations.
鳕鱼和长尾鳕都是三级消费者，因此它们在海洋群落中可能具有重要的结构作用。通过检查胃内容物，确定了来自新西兰查塔姆海隆的 2064 条鳕鱼和 913 条长尾鳕的饮食情况。鳕鱼是底栖杂食动物，长尾鳕是底层洄游性肉食动物。鳕鱼的饮食特征是底栖甲壳类动物，主要是 M. gracilis 和 M. challengeri，以及底栖鱼类，主要是 Macrourids 和从渔船中 scavenged 的内脏。长尾鳕的饮食特征是硬骨鱼类，主要是 Macrourids 和 Merlucciids。使用基于距离的线性模型的多元分析发现，鳕鱼饮食变异性的最重要预测因子是深度、鱼的长度和船只类型（样本是从商业船只还是研究船只收集的），而长尾鳕的则是鱼的长度和船只类型。鳕鱼和长尾鳕之间没有种间捕食，资源竞争主要限于 Macrourid 猎物，尽管鳕鱼和长尾鳕捕食的优势 Macrourid 物种不同。鳕鱼和长尾鳕种内群体平均饮食的聚类分析证实了持久的饮食分离。尽管大小是决定生态过程的核心因素，但相似大小的鳕鱼和长尾鳕具有明显不同的觅食生态，因此可能以不同的方式影响生态系统，并受到生态系统波动的不同影响。
