This study will experimentally elucidate the dynamics of predator evasion by different species and life stages of copepod responding to a model larval fish predator. The PIs will use standard and high-speed videographic and cutting-edge holographic techniques. Predator-prey interactions within planktonic communities are key to understanding how energy is transferred within complex marine food webs. Of particular interest are those between the highly numerous copepods and one of their more important predators, the ichthyoplankton (the planktonic larval stages of fishes). The larvae of most fishes are planktivorous and heavily dependent on copepods for food. In general, evasion success increases with age in copepods and decreases with the age of the fish predator. How this plays out in detail is critical in determining predatory attack outcomes and the effect these have on predator and prey survival. To address this problem, different copepod developmental stages will be tested against several levels of predator competence, and the results examined for: 1) the success or failure of attacks for different combinations of predator and prey age class; 2) the kinematics (reaction latencies and trajectory orientation) for escape attempts, successful and unsuccessful, for different age classes of copepod; 3) the hydrodynamic cues generated by different ages and attack strategies of the predator and the sensitivity of different prey stages to these cues; and 4) the success or failure of the predatory approach and attack strategies at each prey stage. The data obtained will be used to inform key issues of zooplankton population dynamics. For the prey these include: predator-evasion capabilities and importance of detection ability, reaction speed, escape speed, escape orientation, and trajectory irregularity; for the predator they are: capabilities and importance of mouth gape size, stealthiness, hydrodynamic disturbance production, and lunge kinematics.
The broader impacts of this project will be 1) improved scientific insight into predator-prey dynamics as they affect the world's fisheries; 2) training of undergraduates, including underrepresented groups, in research (the University of Hawaii at Manoa is a minority-serving institution, and the P.I. is co-director of the UH Minority Access to Research Program, which provides ready access to qualified undergraduates); 3) training undergraduates and graduate students in outreach activities that educate K-12 age children in biodiversity within marine systems, the role of nervous systems in animal behavior, and the scientific method in their study; 4) a technology-oriented outreach and undergraduate education project focused on drawing high-school and early undergraduates into the appreciation of the wonders of animal behavior as revealed by slow-motion (high-speed video) techniques.
