Application of different external tagging methods to Octopus vulgaris Cuvier, 1797, with special reference to T-bar anchor tags and Petersen disks

摘要

This paper presents a study on the persistence and effects caused by a wide variety of types of tag (loops, rabbit tags, girths, flexible plastic bands, small darts, Petersen disks, T-bar anchor tags, circular plastic tags, rectangular plastic flags, jewellery pins, commercial badges, and burning with liquid nitrogen) applied to the cephalopod Octopus vulgaris Cuvier, 1797, under culture conditions. Preliminary analysis of the results obtained with the different tagging systems indicates that Petersen disks and T-bar anchor tags are the most suitable types. Both provide adequate retention after 1 month (90 % and 80 %, respectively), a maximum persistence of three months, a similar cost, and they are easily recognised externally. However, Petersen disks can produce serious injuries, and require a more laborious insertion process. Therefore, in the final analysis, the insertion of T-bar anchor tags in left arm III can be considered the most appropriate system.