Cannibalism, self-cannibalism and autotomy in the non-indigenous nudibranch Godiva quadricolor

Abstract

Biotic conflict can create evolutionary competition across species in the quest to maintain vital populations. In some cases, this process is driven by conflict among members of the same species, an important selective force in high-density non-indigenous populations. By killing and feeding on their intraspecific competitors, cannibals enhance their chance of survival. Here, we report that the nudibranch Godiva quadricolor (Barnard, 1927) from invasive Mediterranean populations expresses a strong propensity to cannibalism as well as cerata autotomy, a likely antipredatory behaviour. In addition, fourteen cases of self-cannibalistic behaviour during captivity have been recorded, one of the most conspicuous records of this uncommon behaviour up to date. We discuss our observations in the framework of the behavioural traits characterizing non-indigenous populations and biological invasions.