Figure 4. Electric Image of a Plant-Like Background in the Presence and Absence of a Prey Object.

All images in both panels are computed as the difference in transdermal potentials, with and without objects (as described in Materials and Methods).

(A) Six fish positions (see inset, top) for which the electric images (bottom) produced by a 15-disc Hygrophilia plant-like background (0.05 m lateral to fish, as in Figure 3) were calculated. Electric images are barely distinguishable from one another. Fish positions differ from one another by 0.02 m, 0.02 m, 0.03 m, 0.005 m, and 0.015 m (see inset).

(B) Same as in panel (A) except a Daphnia-like prey object (0.3-cm diameter as in Figure 1) was added at a lateral distance of 0.008 m from the skin.