Growth and survival of &lt;i&gt;Octopus vulgaris&lt;/i&gt; (Cuvier 1797) paralarvae fed on three &lt;i&gt;Artemia&lt;/i&gt;-based diets complemented with frozen fish flakes, crushed zooplankton and marine microalgae

Lidia Fuentes,José Iglesias,María Jesús Lago,Fatima Linares,Francisco Javier Sánchez,Gema Pazos

doi:10.3989/scimar.2011.75n4771

Abstract

During one month, paralarvae of common octopus ( Octopus vulgaris ) were fed 3 different diets: (1) Artemia sp. enriched with Isochrysis galbana (AI) complemented with sand eel ( Hyperoplus lanceolatus ) flakes (AH); (2) Artemia sp. enriched with crushed marine zooplankton (AZ); and (3) Artemia sp. cultured with Isochrysis galbana and further enriched with the microalga Nannochloropsis sp. (AN). The highest dry weight (1.6179±0.3861 mg) was registered with the AN diet and the best average survival (67.0%) with the AZ diet. Considering the highest dry weight obtained, the moderate high survival and the fact that with this diet it was possible to attain the adult stage, the AN diet was the most appropriate. The reasons for the best result in growth observed with AN are discussed as: (1) the combination of docosahexaenoic acid (DHA) provided by Isochrysis galbana and the high eicosapentaenoic acid (EPA) content present in Nannochloropsis sp.; (2) the fact that the higher protein/lipid ratio of this diet improves the final dry weight of the paralarvae; and (3) the fact that Nannochloropsis sp. could inhibit the harmful microflora growth in the rearing tank. Regarding nutritional aspects, DHA content per se is not the only determinant factor for growth and survival of O. vulgaris paralarvae, but the presence of a high protein/lipid ratio and a high phospholipid content in the diet could possibly explain the better quality and strength of the paralarvae.

Highlights

The complete commercial rearing process of the common octopus (Octopus vulgaris Cuvier, 1797) has not been successfully achieved due to the high paralarvae mortality in the first weeks of life (Iglesias et al, 2007; Villanueva and Norman, 2008)
The highest dry weight (1.6179±0.3861 mg) was registered with the AN diet and the best average survival (67.0%) with the AZ diet
The highest growth was obtained with AN (P

Summary

Introduction

The complete commercial rearing process of the common octopus (Octopus vulgaris Cuvier, 1797) has not been successfully achieved due to the high paralarvae mortality in the first weeks of life (Iglesias et al, 2007; Villanueva and Norman, 2008). Some authors have successfully reared a small number of paralarvae up to juveniles and even subadults (Rodríguez and Carrasco, 1999; Moxica et al, 2002; Carrasco et al, 2005), using an Artemia-based diet complemented with crab zoeae. All of these experiences were economically unviable. The life cycle of O. vulgaris under captivity was completed for the first time in 2001 (Iglesias et al, 2004) using the same diet All these achievements have always been laboratory experiments that are difficult to reproduce on a commercial scale

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