The effect of stock density on the development of common octopus (Octopus vulgaris Cuvier, 1797) by rearing individually

Denemeler, bireysel ve serbest yetiştiricilik olmak üzere iki grup ve üç farklı stok yoğunluğunda (10, 15 ve 20 kg/m3 başlangıç stok yoğunluğuna göre) yapılmıştır. Denemeler 150 gün sürmüştür. Ahtapotlar günde bir kez ad-libitium ve ağırlıklı olarak isparoz (Diplodus annularis), izmarit (Spicara maena) ve kupez (Boops boops) balıklarıyla beslenmişlerdir. Denemeler süresince sıcaklık 8,7-22,9°C, pH 7,5-8,4, oksijen 5,5-11,2 mg/l, ve tuzluluk ‰35-41 olarak ölçülmüştür. Deneme sonunda ahtapotların ortalama ağırlıkları, stok miktarları ve yaşama oranları arasında istatistiksel olarak fark önemli bulunmuştur (P0,05). Ancak, tam beslenme oranları arasında fark istatistiksel olarak önemli bulunmuştur (P˂0,05).The experiments, the octopuses were divided into two groups as individually and free rearing group, and were stocked at three different densities (based on 10, 15 and 20 kg/m3 of initial stocking densities) were carried out. The trials lasted 150 days. The octopuses were fed once a day as ad-libitium with mainly fish, annular seabream (Diplodus annularis), picarel (Spicara maena) and bogue (Boops boops). During the trials, the water parameters were measured as 8.7-22.9°C, 7.5-8.4 pH, 5.5-11.2 mg/l of oxygen, and 35-41‰ of salinity. At the end of the experiments, the differences in the average weight, stocking densities and survival rates were found statistically significant (P<0,05). The differences between the specific growth rates, the feeding percentages, food conversion rates, and feed efficiencies were not found statistically significant (P˃0,05). However, the significant differences were found between the absolute feeding rates (P