Food habits of some deep-sea fish off South Africa's west coast and Agulhas Bank. 1. The grenadiers (Teleostei: Macrouridae)

Abstract

The food habits of 10 species of grenadier collected from the upper continental slope off South Africa's west coast and Agulhas Bank are described. Three feeding strategies were identified. Members of the demersal micro- or mesocarnivore feeding guild and grazer feeding method include Caelorinchus braueri, C. simorhynchus, juvenile Coryphaenoides striaturus, Lucigadus ori, Malacocephalus laevis, Nezumia brevibarbata, N. micronychodon and N. umbracincta. A second strategy, that of Caelorinchus matamua and adult Coryphaenoides striaturus, involved switching approximately equally from demersal grazing to midwater picking or stalking. The deep-pelagic Mesobius antipodum displayed a third strategy, that of a midwater mesocarnivore picking or stalking. Ontogenetic dietary shifts were noted for the primarily demersal grazers Caelorinchus braueri, C. simorhynchus, Coryphaenoides striaturus and Malacocephalus laevis. Mesopelagic fish, shrimps and squid formed part of the diet of all species. These prey, taken at the bathyal/deep-pelagic interface, are an important source of energy transport from productive surface waters to the deep benthos.

Keywords: deep-sea fish, diet, feeding, grenadiers, Macrouridae, South Africa

African Journal of Marine Science 2005, 27(2): 409–425