Effects of individual rearing method on fattening of common octopus (Octopus vulgaris, Cuvier 1797)

In this thesis, effects of individual rearing method on fattening reaching to 2.5-3 kg/octopus of common octopus (Octopus vulgaris) was investigated. The specimen were divided into two groups; Group B, the octopuses were isolated and placed from each other by individually, transparent plastic bag with a lid, perforated and Group S (control group), the octopuses were took placed as free with PVC pipes as shelters as equal the octopus number, in two 450 lt circular polyester tanks ( 430 l water volume). Octopuses average initial weights were 1187±313 g (2 female, 3 male) for Group B and 1093±243 g (4 females, 1 male) for Group S were fed mainly with fish, annular seabream (Diplodus annularis), picarel (Spicara maena) and bogue (Boops boops) during 135 days. Throughout the study, the average sea water temperature, salt, dissolved oxygen and pH were measured as 14.2±1.6°C, ‰38.9±0.9, 9.2±0.7 mg.l-1, 8±0.1, respectively. At the end of the study, the average weights of the individuals were weighted as 2836±9.42 g for Group B and 2293±330 g for Group S. The survival rate of the both groups was calculated as 100%. The average absolute growth rates (AGR) were estimated as 44,2±19,9 body weight (gr)/day for Group S and 65,4±30,4 body weight (gr)/day for Group B (P>0,05). The main food conversion rates (FCR) were calculated as 3,3±1,7 kg for Group S and 2,5±0,6 kg for Group B (P>0,05). Also, in Group S, the spawning was observed that following octopuses' mating behaviours.