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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. [ABSTRACT FROM AUTHOR]

The article discusses research done on feeding habits and niche separation among several deep-sea chimaeroid fishes found in Chatham Rise, New Zealand, including Hydrolagus (H.) novaezealandiae, H. bemisi and Harriotta (H.) raleighana. The study procedure included the examination of the digestive tract contents of the fishes, which were fed on benthic infauna and epifauna. Results revealed that the diets of H. novaezealandiae, H. bemisi and H. raleighana were characterized by crabs and sea urchins, by crabs and polychaetes, and by polychaetes and molluscs, respectively.