Enhanced feeding by pelagic juvenile myctophid fishes within a region of island-induced flow disturbance in the Coral Sea

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 203:263-273 (2000) - doi:10.3354/meps203263 Enhanced feeding by pelagic juvenile myctophid fishes within a region of island-induced flow disturbance in the Coral Sea David Rissik*, Iain M. Suthers School of Biological Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia *Present address: Estuary Management, Department of Land and Water Conservation, 10 Valentine St, Parramatta, New South Wales 2150, Australia. E-mail: drissik@dlwc.nsw.gov.au ABSTRACT: The feeding success of post larvae and juveniles of 2 myctophid fishes (Diaphus kapalae and Myctophum sp.) was compared between the free stream and a flow-disturbed region in the lee of Cato Reef in the south Coral Sea using particle-size analysis. Both taxa fed more successfully in the disturbed region than in the free stream, where uplifting resulted in up to 50% greater concentrations of small (250 to 1000 µm equivalent spherical diameter) prey items at depths between 30 and 70 m around the thermocline. Gut fullness in both taxa was significantly related to the concentrations of small-sized zooplankton (D. kapalae: r = 0.63, p < 0.05; Myctophum sp.: r = 0.55, p < 0.05). There were, however, differences in the sizes of food items consumed in the free stream and the disturbed region and between the 2 taxa of fishes studied. Non parametric multi-dimensional scaling analysis indicated that similar-sized individuals of D. kapalae and Myctophum sp. within a region consumed a different particle-size community, probably enabling them to co-exist. The taxonomic composition of the diets of the 2 taxa reflected the available prey items around the island. In an oligotrophic environment such as the south Coral Sea, island-induced disturbance appeared to be an important contributor to the pelagic food web. KEY WORDS: Particle size analysis · Island mass effect · Juvenile myctophids · Feeding success · Optical plankton counter Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 203. Online publication date: September 18, 2000 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2000 Inter-Research.