title: The effects of contrast and position on habituation to models of predators in eastern banded killifish (Fundulus diaphanus).
abstract: We investigated habituation in killifish (Fundulus diaphanus) to repeated exposure of predator models of varying shades in two positions (above and below) against backgrounds of varying shades. Killifish that had habituated to a model of a given shade recommenced responding to a model of a different shade when the contrast between the second model and its background was greater than that of the first. They showed no increase in response to a model-background combination of lower contrast (Experiment 1). After a single presentation of one model-background combination (i.e. minimal habituation and sensory adaptation) an increase in contrast again resulted in an increase in response, and a decrease in contrast resulted in a lower response (Experiment 2). The killifish reacted to models which were presented above the shoal following presentations below the shoal, but not if the order was reversed. This difference was found with models darker or lighter than the background (Experiment 3). These results were interpreted in relation to the predators present in the environment in which the killifish live, and the visual mechanisms with which the killifish perceive these predators.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: C
authors.initials: C
authors.lastname: Welch
authors.forename: P
authors.initials: P
authors.lastname: Colgan