Document Type

Internship Report

Publication Date

Fall 2017


The objective of this study was to determine if physically fit Aplysia californica, achieved by rearing in exercise conditions, exhibit changes to learning reflexes when trained using an associative training technique. One hundred twenty A californica were used for this study. Sixty animals were reared in an exercise regime and 60 animals were reared in standard hatchery conditions, unexercised, to compare to exercise animals. We trained 15 unexercised animals and 15 exercised animals for study at each of two time points. The remaining animals served as untrained controls, both exercised and unexercised. Percent Savings was calculated to represent the difference between critical learning events in training and retraining [1-(time in the mouth retrain/time in the mouth train)]. The differences were assessed with a Mann-Whitney U test. None of the comparisons (Exercise vs. Control, Segment One vs. Segment Two, Segment One Exercise vs. Segment One Control, and Segment Two Exercise vs. Segment Two Control) were significant according to the statistics (P=0.05). A P-value of 0.0703 was found in the comparison between Segment One and Segment Two meaning that age plays a major role in learning in Aplysia. Data collection consisted of recordings of an animal’s learning over 2 training periods, separated by 24 hours, to reject a probe it determines is inedible food. The probe constructed with edible algae wrapped in nitrex netting so that it cannot be swallowed. The probe is brought to the animal’s mouth to stimulate it to take it in the mouth. The animal’s behaviors with the probe are observed while a timer keeps track of elapsing time. Twenty-four hours after initial training, animals are retrained. We proved that the Aplysia learned when we compared the timing of oral manipulation events between training and retraining. An unpaired t-test determined that all treatment groups exhibited a statistically significant difference between time the inedible probe was in the mouth during training and the time the inedible probe was in the mouth during retraining (P=0.05).


Department: MBE

MPS Track: TME

Location: The National Resource for Aplysia Lab, University of Miami

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