Preliminary trials on the use of large outdoor tanks for the ongrowing of Octopus maya juveniles

摘要

Octopus maya has high growth rates, direct embryonic development and high hatchling survival, making it a good candidate for aquaculture diversification. The present study was designed to evaluate growth rate, survival and food conversion of O. maya juveniles cultured in outdoor tanks. Octopuses were captured from the wild during the fishing season, and fed discarded fish heads and whole crabs. Three trials were conducted between 23 and 32 days, in September (trial 1), October (trial 2) and November (trial 3) where a decrease in sea water temperature was registered (29–24 °C, from September to November respectively). Octopuses were held in three outdoor tanks of 5 m2 of bottom area and 0.5 m deep, aerated sea water and water flow allowing 10% of water exchange per day. Initial density was between 2.9 and 3.8 kg m−3 with different initial mean weight of 542.3 ± 18.8, 493 ± 11.9 and 321 ± 7.8 g, for trials 1, 2 and 3 respectively. Specific growth rate varied between 1.8 and 2.7% BW day−1 with no apparent relation with the culture temperature. These results put in evidence that tanks used are adequate for the ongrowing of O. maya juveniles, with commercial size being attained in a few weeks.