Movement estimation of Octopus vulgaris Cuvier, 1797 from mark recapture experiment

The movements of Octopus vulgaris were investigated by a mark–recapture study (1604 specimens tagged), carried out during a commercial octopus traps fishery, at a depth of 20–50 m, over a rocky substrate area of the Sardinian Sea (central western Mediterranean Sea). Overall 87 specimens (56 males and 31 females) were recaptured after 4 and 63 days from the tagging. The difference between the depth at release and recapture varied up to 5.0 m but in 100% of males and in 80% of females the variation was less than 3.0 m. Theoretical straight distances travelled by recaptures ranged from 9 to 5800 m in males and from 9 to 1700 m in females, regardless of the days of freedom. There was no correlation between distances and sex or body size and no marked orientation was found except for medium males that move preferentially in the south western direction. The movements of O. vulgaris , generally linked to the availability of food, partners and/or shelters, in this study were limited within 1 km in most of the recaptures (84–86%). This high site fidelity, within the rocky area investigated, could represent useful information for management plans of this species like the creation of small no-take areas.