PSYCHOLOGY MASTER'S THESIS ABSTRACT

Alexander Weiss

MA-Research
August 1996

Conditioned Food Aversion in the Leopard Shark triakis semifasciata

    Ten leopard sharks were used to test whether they formed conditioned food aversions (CFAs) and whether the CFAs resembled those of other predators.
    Subjects were tested during four 3-day blocks consisting of two days with a  non-target food and one day with a target food.  On the first target day subjects received lithium or sodium chloride injections after eating.
    Latency, percent eaten and sixteen behaviors were analyzed with a mixed design ANOVA.  The traditional measures of latency and food eaten did not reflect CFAs.  Lithium animals showed fewer speed increases on target days.  Sodium animals showed more speed decreases on target days.  The data suggest that lithium groups behaved sluggishly and cautiously around target foods.  This may be because leopard sharks scavenge for some of their food.  During low prey density strong CFAs might form when the sharks attempt to eat potentially toxic carrion.  These pressures might favor caution around rather than the rejection of these foods.

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