Reproductive development versus estimated age and size in a wild Mediterranean population of Octopus vulgaris (Cephalopoda: Octopodidae)

First investigation on the relationship between reproductive development and estimated age/size in a wild population of Octopus vulgaris was performed in the Sardinian waters (central western Mediterranean Sea) in order to have a useful tool for integral fishing management in the area. Full sexual maturity was registered from April to August for females with a peak in summer whereas for males it was observed all year round. Size at maturity was 320 g for males (70 mm dorsal mantle length (ML)) and 520 g for females (120 mm ML). From 61 to 465 and from 80 to 390 daily growth increments were counted on the lateral wall of the upper beak, respectively in males and females, obtaining a positive relationship between estimated age and size of the specimens. The sexual maturation was primarily size-dependent with a secondary role played by the age especially in males. The estimated age of 390 and 465 days respectively of the largest female (4661 g) and male (5344 g) as well as that of two males at the end of their lives ('spent') of 310 and 420 days old, have suggested a lifecycle of about 1 year for both genders.