COPEPOD GRAZING IN TURBULENT-FLOW - ELEVATED FORAGING BEHAVIOR AND HABITUATION OF ESCAPE RESPONSES

When exposed to non-turbulent followed by turbulent conditions, the co pepod Centropages hamatus initially responded with numerous escape rea ctions and increased foraging behavior. However, when the cycle of non -turbulent followed by turbulent flow was repeated for several consecu tive cycles, the two behaviors followed distinctly different patterns. Foraging effort increased during the first two cycles, and then remai ned at high levels during both turbulent and non-turbulent periods (pe riod durations of 12.5 and 25 min). In contrast, escape behavior habit uated rapidly during each turbulent period and dishabituated during ea ch non-turbulent period. These response patterns are suited to the str ongly intermittent nature of oceanic turbulence and allow C.hamatus to utilize the benefits of enhanced encounter rate, while minimizing the expense of unnecessary escape responses.