title: Diets of deepwater oreos (Oreosomatidae) and orange roughy Hoplostethus atlanticus.
abstract: The diets of black oreo Allocyttus niger, smooth oreo Pseudocyttus maculatus, spiky oreo Neocyttus rhomboidalis and orange roughy Hoplostethus atlanticus were determined from examination of contents of 240, 311, 76 and 415 non-empty stomachs, from fishes sampled by bottom trawl on Chatham Rise to the east of South Island, New Zealand. Hoplostethus atlanticus had an opportunistic predatory strategy with a broad diet dominated by prawns and mesopelagic teleosts, but with substantial components of mysids and cephalopods. Pseudocyttus maculatus was strongly specialized on gelatinous zooplankton (jellyfish and salps). Allocyttus niger consumed mainly salps and hyperiid amphipods, and to a lesser extent fishes, prawns, mysids and copepods. Neocyttus rhomboidalis primarily consumed salps, along with mysids, euphausiids and fishes. Only P. maculatus did not exhibit significant ontogenetic variation in diet. The diets were also influenced by year and bottom depth. Differences in the distributions and diets of the four species probably reduce conflicts in resource use.
authors.affiliation: National Institute of Water and Atmospheric Research Limited (NIWA), P. O. Box 14-901, Kilbirnie, Wellington 6021, New Zealand.
authors.forename: J S
authors.initials: JS
authors.lastname: Forman
authors.affiliation: National Institute of Water and Atmospheric Research Limited (NIWA), P. O. Box 14-901, Kilbirnie, Wellington 6021, New Zealand.
authors.forename: P L
authors.initials: PL
authors.lastname: Horn
authors.affiliation: National Institute of Water and Atmospheric Research Limited (NIWA), P. O. Box 14-901, Kilbirnie, Wellington 6021, New Zealand.
authors.forename: D W
authors.initials: DW
authors.lastname: Stevens
mesh_terms: D000818:Animals; D004032:Diet; D005247:Feeding Behavior; D005399:Fishes / Q000502:physiology*; D009520:New Zealand; D011235:Predatory Behavior
keywords: Oreosomatidae; Trachichthyidae; niche; trophic relationships