Defensive strategies of European spiny lobster Palinurus elephas during predator attack

The aim of the present work was to reveal the behaviour of the European spiny lobster Palinurus elephas (Fabricius, 1787) during encounters with predators. The study was conducted in a tank, exposing lobsters individually or in groups to a single specimen of the European conger eel or the common octopus. The behaviours of the lobsters, their sounds and the behaviours of the predators were recorded using a digital audio-video underwater acquisition system and analysed. A behavioural event not found in literature, dubbed 'Alert' by the authors, was described. The results showed that the most recurrent events were Alert, Point and Whip, which have the function of controlling the predator with the antennae, while maintaining the predator-prey distance. Moreover, a strong association between Tail Flip and Lunge (events that were stimulated in response to an imminent danger to life) with the sounds emitted by lobsters was observed. Significantly more sounds were emitted during the tests with single lobsters compared to grouped lobsters. As a result of the present study, the European conger eel may also be considered a potential natural predator of the European spiny lobster.