SHELTERING AND FORAGING SUBSTRATE USES OF THE ARC-EYE HAWKFISH PARACIRRHITES ARCATUS (PISCES, CIRRHITIDAE)

A combination of free-ranging snorkel surveys and focal-animal observa tions was used to evaluate substrate use by the arc-eye hawkfish Parac irrhites arcatus, a typical cirrhitid recognized for its conspicuous ' 'perching'' and ambushing behavior, The arc-eye hawkfish used differen t substrates for sheltering and for foraging. Pocillopora meandrina, t he only common species of closely branched coral in the main Hawaiian Islands, was the perch most frequently encountered (>96% of all cases) on snorkel surveys at seven sites on the leeward side of the Island o f Hawaii. P. arcatus refuged within Poc, meandrina whenever predators approached closely, but darted out from coral heads to feed. Foraging strikes were directed mainly at targets on benthic substrates surround ing Poc. meandrina refuges; strikes were primarily directed (81-96% of all strikes) at prey on rock/dead coral substrate that dominated cove r (43-90%) at the study sites. P. arcatus also fed to a major extent w ithin the near-bottom water column. The dichotomy between preferred fo raging and sheltering substrates is discussed relative to the trade-of f between foraging benefit and risk of predation hazard when the two s ubstrates differ.