Individual rearing of common octopus (Octopus vulgaris Cuvier, 1797) in tanks: Preliminary results

The effects of individual rearing technique on the growth and survival of Octopus vulgaris (Cuvier, 1797) were investigated. Therefore, wild octopuses were reared in the transparent, perforated and caped polyethylene terephthalate (PET) pots (10 l). The assay was established as one free group rearing as a control (12.7 kg/m3 of stoking density) and two individual rearing groups as I1 and I2 (13.8 kg/m3 and 18.3 kg/m3 of stoking density, respectively). The individuals were fed mainly fresh or thawed fish at 5% body weight per day. The experiments lasted for 120 days. The acclimatization period of the octopuses lasted within 3-5 days in the individual rearing and 7-10 days in the free group rearing. The final survival rates were 100% for the control and I1 or 85.7% for I2 (P>0.05). Statistically, differences were not found among the growth or specific growth rates (between 0.5 and 0.6%/day for the trials) (P>0.05). The maximum density (30.7 kg/m3) was obtained from the I2 trial