Figure 1.
Catch per unit effort (CPUE) of perch (white bars) and roach (grey bars) in one brown and one clear water lake during day (a) and night (b).
Figure 2.
Selectivity of perch (white bars) and roach (grey bars) in one brown and one clear water lake during day (a) and night (b).
The horizontal line at 0 correspond to the null hypothesis of equal selection of prey, values close to 1 represent high prey selection and values close to −1 represent low selection.
Figure 3.
Pikeperch prey selection of perch (white bars) and roach (grey bars) at different visual ranges at day (a) and night (b) in the laboratory experiments.
The horizontal line at 0.5 represents the null hypothesis of equal prey selection. Error bars denote 1 SE.
Table 1.
The effects of light condition and visual range on prey selectivity of pikeperch.
Figure 4.
Behavioural parameters of pikeperch foraging on perch (white bars) and roach (grey bars) at visual ranges of 0.5 and 2 m.
Behavioural parameters include number of interests (a) and strikes (b), as well as capture success (c). In the analyses of attack distances (d), data for the two prey species are pooled. Error bar denote 1 SE.
Figure 5.
Escape distance of perch (white bars) and roach (grey bars) at a visual range of 0.5 and 2 m.
Error bar denote 1 SE.
Table 2.
The effects of visual range (VR, random factor) and prey species (Prey, roach or perch, fixed) on pikeperch foraging behaviours.