Crab and mollusc shell drilling by Octopus vulgaris (Mollusca: Cephalopoda) in the Ria de Vigo (north-west Spain)



Octopus vulgaris living in the Ria de Vigo, north-west Spain, sometimes drills a cavity in the carapace of crabs and shells of molluscs. These holes have features with the same characteristics as those made in molluscs by O. vulgaris and in crabs by Eledone cirrhosa when isolated in aquaria. This is the first report of drilling the carapace of crabs by Octopus vulgaris.