Foraging Flexibility in Pumpkinseed (Lepomis gibbosus); Influence of Habitat Structure and Prey Type

Abstract

Foraging behaviour of pumpkinseed (Lepomis gibbosus) was investigated in feeding arenas containing different habitat structures and prey types in two sets of experiments, each of three successive 10-d blocks. (A) Two groups of eight foraged in open-water habitats on different prey items: group 1 was presented with prey in the order white worms, fruit flies, white worms and group 2 with fruit flies, white worms, fruit flies. Both capture rate and success increased with successive trials for both prey types, indicating that foraging efficiency increased with experience. Shifts from one prey type to another changed performance; however, overall foraging efficiency did not change dramatically when fish were shifted back to feeding on a previously encountered prey type. (B) Two groups of eight foraged on white worms: group 1 in the habitat order open water, structured, open water and group 2 in structured, open water, structured. Fish fed faster in an open-water habitat but were flexible in a structured habitat. When fish returned to feeding in a familiar habitat type, behavioural patterns were very flexible. The results of these two experiments show that the foraging behaviour of pumpkinseed is relatively sensitive to temporally and spatially separated prey and habitat types.