Common octopus (Octopus vulgaris Cuvier, 1797) juvenile ongrowing in floating cages

The study of Octopus vulgaris culture has recently undergone a significant increase in Spain. The need to diversify the available number of farmable marine species, taking into consideration biological and economical aspects, makes the common octopus a potential candidate for industrial culture. In this article, results for four growth trials using O. vulgaris, which were held in captivity in Asturias (Spain) during 2002 and 2003, are presented. A rectangular floating cage of 4 m3 containing PVC tubes as refuges was used in each trial. Each trial lasted 3 months. A mixed diet of fish, crabs and mussels was used to feed the animals. Different initial densities (24.5, 10.7, 12.6 and 11.9 kg m− 3) were tested. These produced 41.0%, 17.0%, 36.0% and 18.7% mortality, 0.51%, 1.46%, 0.64% and 1.54% specific growth and 7.02, 29.39, 8.69 and 33.18 g daily weight increase, respectively. There were no serious problems of cannibalism. Best results concerning growth and survival were obtained in summer–early autumn, with a mean water temperature of 15.9 ± 1.6 and 16.7 ± 1.7 °C. Time of the year and diet seem to be the main factors that have influence on O. vulgaris commercial culture success.