Evidence for a specific short-term memory in the cuttlefish, Sepia

Cuttlefish quickly learn to inhibit their predatory motor pattern when shown prawns in a glass tube. 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 considered as the product of two separate short- and long-term memory stores. In this study, we have investigated the fact that the retention seen after a brief delay of the training phase corresponds to a true effect of learning. We compared animals under three experimental conditions. In two, there was a unique training trial of different duration (5 or 20 min), a third group served as controls. Our results demonstrate that the control situation failed to reduce the level of attack; in contrast the short-term retention, obtained after a single learning trial, is related to a specific short-term memory process.