Abstract
Cinematography of the feeding behavior of five adult female Calanus finmarchicus revealed considerable individual variation in time allocation to three types of behavior: "slow swim," in which only feeding appendages were moving, "jump," in which first antennae and posterior swimming legs were moving, and "break," in which no appendages were moving. Filming was done at three different concentrations of unialgal cultures and in filtered seawater. Animal-to-animal variation within given food concentrations was significant ( alpha = 0.01, t-test). The significant differences ( alpha = 0.01, Cochran's Q-test) in mean responses to different food concentrations were complicated by high individual animal variability within food concentrations. Behavioral transitions per minute, and durations of individual periods of slow swimming and break were similarly variable. There was no relation between time spent feeding and concentration of food. We conclude that cinematographic techniques can precisely determine behavioral time allocation, but that sufficient replication must be performed.