ETD

• behaviour
• cognition
• coleoid cephalopods
• conditioning hormesis
• glutathione peroxidase
• learning
• marine ectotherms
• marine heat waves
• predation behaviour
• Sepia officinalis
• superoxide dismutase
• thiols

Marine Heat Waves (MHWs) are becoming more intense and frequent due to climate change. Ectothermic organisms are particularly sensitive to temperature change. Nevertheless, in different species it has been observed the acquisition of resistance to thermal stress through the precocious exposition to mild intensity of such stress during the early developmental phases – a process called hormesis. In this study we investigated the possibility of an acquisition of resistance to thermal stress in the cuttlefish (Sepia officinalis). We exposed to a thermal treatment (CTRL, T1 and HW) the cuttlefish during the embryonal phase and then we exposed them to a second thermal treatment (CTRL and HW) after hatching. Cuttlefishes were sampled to measure the activity of two antioxidant enzymes (SOD and GPx), and Thiols Concentration. Cuttlefish exposed to T1 or HW, and then to CTRL were on average heavier than those treated first with CTRL and then with HW and had a higher GPx activity than all the other individuals. We decide to conduct a study on the effect of simulated MHWs on behaviour (predation behaviour) and learning (PT test) of Sepia officinalis in two separate groups. We exposed to a thermal treatment (CTRL and HW) cuttlefishes after they hatched. In the behavioural group we found that the Latency of First Orientation was significantly shorter for cuttlefish exposed to heat stress temperatures than to individuals of the control group.