Consistent individual differences in the behavioural responsiveness of adult male cuttlefish (Sepia officinalis)

Abstract

Consistent individual differences in clusters of behaviour (animal personalities) are being increasingly recognized by researchers of different disciplines, but studies on invertebrates are still scanty. In order to test for the presence of personality-like individual profiles we assessed the behavioural responsiveness of adult male cuttlefish temporarily kept in captivity and individually housed. We used three different stimulations, adapting a protocol established for octopuses (Mather and Anderson, 1993) to assess individual differences (personalities). In the "alerting test" the behaviour was scored after the human observer lifted the cover of the tank. In the "threat test" the behaviour was scored after the animal was touched with a stick. In the "feeding test" the behaviour was scored after the animal was given a live prey. The relationship among behavioural responses was analysed by principal component analysis, which allowed identifying three dimensions along which individual differences were maximal, accounting for 39.6, 15.6, and 10.3% of the total variance. We found marked individual differences that were consistent across the three tests with respect to behaviours such as floating, staying at the bottom of the tank, and moving the fins. However, behaviours such as "moving" and "changes in body patterning" showed context-dependent variation. This study provides evidence of personality dimensions in cuttlefish with implications about welfare of cephalopods used in research in view of the new EU regulations.