A jelly mind: development of a classical conditioning procedure in the jellyfish Aurelia aurita

Cognitive abilities have been extensively studied in vertebrates, whereas our understanding of learning mechanisms in invertebrates, particularly within the phylum Cnidaria, remains limited. This study investigates the effectiveness of a classical conditioning procedure in the jellyfish Aurelia aurita. Specimens were divided into two separate groups and exposed to either a blue or green environment paired with food administration over a two-week training period. Following this phase, jellyfish were tested by being placed in each coloured environment without food, while their kinetic responses (i.e., the number of pulsations) were observed and recorded. An increased pulsation rate in the colour-associated environment would suggest a learned association between the visual cue and food, indicative of a basic form of associative learning. No evidence of learning has been reported with the present procedure. Methodological considerations are discussed in this thesis.