We compared the memory of damselfish Stegastes fuscus in an aversive and appetitive
conditioning task. Fish were trained to associate the sides of the tank that corresponded
to the presence of a positive (conspecific presence) or negative (electroshock) stimulus.
After two conditioning sessions, they were tested for learning. The fish conditioned
to the stimulus were then re-tested for memory retention after 5, 10 or 15 days. Both
the positive and negative rewards were associated with a specific side of the tank,
indicating learning ability. Additionally, in both contexts, S. fuscus stored the
information learned and showed similar behavioural patterns after 5, 10 and 15 days,
suggesting long-lasting memory. For the ecological context, long lasting memories
of social encounters outcomes and negative experiences of threatening situations may
confer advantages that ultimately affect fishes' fitness.