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 dis- turbed 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 70m 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, dif- ferences 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.
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