EFFECTS OF DIFFERENT TANK VOLUMES AND FEEDING REGIMES ON GROWTH, SURVIVAL AND LIPID COMPOSITION OF Octopus vulgaris PARALARVAE

摘要

The common octopus (O. vulgaris) is an important fishery species with potential for aquaculture industry. However, the lack of a rearing methodology for the paralarvae stage as prevents the commercial culture of this species.The aim of this study was to evaluate the effects of tank volumes (100L and 500L) and feeding regimes (Grapsus adscensionis zoeae, Artemia spp. nauplii and juveniles enriched with Nannochloropsis spp.) on the growth, survival and lipid composition of octopus paralarvae. The rearing was performed in a flow-through seawater system, at a density of 3 paralarvae/L, under a light regime of200 lux and photoperiod 12L:12D. After 15 days of rearing, the diets and tank volumes used had a clear influence on growth and survival of paralarvae. In 100 L tanks, the best results of growth performance were obtained with G. adscensionis (Instantaneous Growth Rate, IGR, 5.97% BW/d), which displayed a survival of 28.67%, gained more than twice of its initial weight and were larger than paralarvae fed Artemia spp. (P<0.05). In 500 L tanks and with G. adscensionis as first prey, even better growth results were obtained. The size of paralarvae at the 16* day of culture was significantly larger (1.90 ± 0.09 mm Ventral Mantle Length, VML) than that obtained in 100 L tanks (1.76 ± 0.20 mm VML). The survival rates were 2.5% at the 77th day and 0.1% after 160 rearing days. At the end of this experiment, one benthic-stage octopus with a VML of 13.00 mm and wet weight of 2.17g was obtained.