Meeting Abstract
Associative learning can be defined as changes that an organism makes in its behavior due to associations it forms between stimuli in its environment. Research on associative learning in echinoderms is limited, though some studies suggest that it is present in sea stars. We aimed to expand this area of study by investigating associative learning in the brittle star Ophioderma brevispinum. Specifically, we tested whether the animal could learn to associate light and food stimuli. Brittle stars tend to hide from light, whereas they move around actively when searching for food. Thus, we expected the animal to begin moving around actively when exposed to light if it learned to associate light with food. Ten brittle stars were kept in the dark at all times except during a 15-minute trial period every 24 hours. There were a total of four trial phases. In Phase 1, brittle stars were fed four hours after the trial period, as a way of keeping food and light stimuli uncoupled. In Phase 2, brittle stars were fed at the beginning of the trial, as a way of pairing food and light stimuli. In Phase 3, brittle stars were fed immediately after the end of the trial, to test whether they had learned to associate light with food. If an animal exhibited feeding behavior in the presence of light but before the presence of food, we considered this an indication that it had learned to associate the two stimuli. Finally Phase 4 was a repeat of Phase 1, to see how long learning persisted after stimuli were fully uncoupled. During every trial, we counted the number of individuals that exhibited feeding behavior within the 15-minute trial period, and Chi-square tests were used to test the differences in the animals’ responses between the different phases of the experiment. Results will be discussed.
