Assessment of diet and temperature on the overall performance of Patagonian red octopus ( Enteroctopus megalocyathus , Gould) paralarvae

The limitation to sustain the Patagonian red octopus Enteroctopus megalocyathus aquaculture is the lack of an efficient diet to obtain high survival during the paralarvae stage. This work has studied the performance of paralarvae under different combinations of feeds and temperatures using a factorial design. The diets were based on various Artemia enrichments: (a) Nannochloropsis sp, (b) Ori-gold (Skretting) and (c) LC60 (Phosphotek). The temperatures chosen were in accordance with those found in their environment: 10 degrees C (winter), 12 degrees C (spring-autumn) and 14 degrees C (summer), by triplicate. The factorial combinations were tested in two experiments with paralarvae of different age: Exp 1, from newly hatched to 14 days after hatching (DAH), and Exp 2, from that point to 42 DAH. It was concluded that temperature was the primary variable affecting mortality, feed intake, relative weight condition index, morphometric variables and trypsin activity. The enriched Artemia diets had the main impact on the leucine-aminopeptidase activity, and on the fatty acid contents, mainly 20:5n-3 (EPA) and 22:6n-3 (DHA). Paralarval growth was increased by temperature with only one diet and at a certain age. Nutritional requirements varied between early and late paralarvae, and the possibility of changing the diets according to the development age is discussed.