Predation by Octopus vulgaris in the Mediterranean

Abstract

Abstract. Octopus vulgaris consumes at least 22 molluscan and several crab species in the Mediterranean off the coast of France. Collections of prey discards in octopus middens and in areas inhabited by octopuses revealed that molluscs comprise an estimated 80% of the O. vulguris diet. Octopus predation is probably an important source of mortality for many of these prey species, causing up to 60 % of the mortality within the size ranges sampled. O. vulgaris does not selectively consume particular sizes of its three most important prey species, the bivalves Pilaria chione and Venus verrucosa and the abalone Haliotis tuberculata. Analysis of octopus drill holes on the two bivalve species showed that their locations were nonrandom, whereas the distribution of drill holes in the abalone was not distinguishable from random.