Temperature-dependence of the purple sea urchin Paracentrotus lividus: a behavioural approach

Abstract

[eng] Climate change is increasingly impacting species and communities around the globe. Ocean warming is particularly threating for marine ecosystems and many species of marine invertebrates are especially sensitive to raising temperatures. We studied the behavioural response of the purple sea urchin (Paracentrotus lividus), a common herbivore of the Mediterranean Sea, to a thermal regime by performing an experiment under controlled laboratory conditions. We evaluated changes in weight and the behaviour of sea urchins after 11 days of exposure to four targeted temperatures under a sublethal range (20, 23, 26, and 29 ºC). Sea urchins modified their behavioural responses when exposed to increasing temperatures, while no significant results for changes in weight were found. Increasing temperatures induced higher mobility and activity, while longer times were required for the righting response. These results suggest a strong temperaturedependence of the behaviour of P. lividus and reveal the need for further studies on consequences of climate change on marine invertebrates.