Time differences in the emergence of short- and long-term memory during post-embryonic development in the cuttlefish, Sepia
Résumé
When shown prawns in a glass tube, cuttlefish quickly learn to inhibit their predatory behaviour. The available literature suggests that cuttlefish show an excellent retention between 2 and 8 min, a recovery of the predatory responses around 20 min, and good retention after 1 h of the training phase. These results have been interpreted as the product of separate short- and long-term memory stores. The retention performance for cuttlefish that learned not to attack prey was studied during their post-embryonic development at intervals corresponding to the rate of short- (5 min) and long-term (60 min) memory storage definite in adult cuttlefish. Short-term memory appeared fully operational as early as 8 days of age, whereas the 60-min retention performance increased progressively between 15 and 60 days of age. Results suggest that during post-embryonic development, there is a time lag between the establishment of short- and long-term memory systems.