Meeting Abstract

P1.68  Friday, Jan. 4  Selectivity and Capture Success in Larval Clownfish Amphiprion ocellaris Preying on Evasive Copepods JACKSON, J.M.; LENZ, P.H.*; University of Hawaii at Manoa; University of Hawaii at Manoa petra@pbrc.hawaii.edu

Predator-prey interactions shape pelagic communities and are drivers for evolutionary adaptation. Survival through the larval stages is particularly risky for most marine fishes, which start life as zooplanktivorous ichthyoplankton. Little is known about the feeding behavior of coral reef fish larvae during this critical phase, but gut analyses suggest that they feed on a wide variety of prey including copepods. Larvae of the clownfish Amphiprion ocellaris and the evasive copepod prey Parvocalanus crassirostris were used as a model system to investigate larval reef fish predatory behavior during the planktonic phase. Larval fish were presented with multiple copepod life stages in both mixed and single prey-type assemblages, and their predatory behavior was recorded on video and analyzed frame-by-frame to evaluate predator-prey encounters. A. ocellaris growth characteristics were measured and compared to prey size. First feeding larvae were able to detect and capture P. crassirostris nauplii, but could not capture copepodites. On day 3 post-hatch copepodites were captured with an initial success rate of 22%, while adult copepods were first captured on day 8 post-hatch with an initial success rate of 4%. Early in development, A. ocellaris preferentially attacked nauplii and failed to attack adults. By 10-14 days post-hatch, the larvae attacked all copepod life-stages equally, however, capture rates were skewed towards nauplii. A. ocellaris mouth gape size was a poor predictor of prey size and would have predicted consumption of all P. crassirostris life stages by day 2 post-hatch. This study provides novel insights into the developmental progression of fish predatory behavior from first feeding to age of settling.