The aim of this study was to evaluate growth, biochemical composition and dietary nutrients utilization in Octopus vulgaris fed on four diets based on bogue Boops boops, from different origin and in two presentations: fresh discarded bogue (aquaculture by‐product) (DB‐f), fresh wild bogue (low price trash species) (WB‐f), discarded bogue agglutinated moist diet (DB‐m) and wild bogue agglutinated moist diet (WB‐m). Diets based on DB showed higher lipid content (19–26% dw) than those based on WB (5–6% dw). Octopuses fed on DB‐based diets showed higher growth (1.5–1.9% day−1) and higher protein efficiency ratio (0.64–0.69) than those fed on WB‐based diet (1.1–1.5% day−1 and 0.36–0.37 respectively), which suggests good utilization of dietary lipids and also a possible protein sparing effect by lipids in O. vulgaris. Octopuses fed on diets presented fresh showed a higher growth (1.9–1.5% day−1) and a higher feed efficiency (62–65%) than those fed on agglutinated diets (1.1–1.5% and 52–60% day−1 respectively). Regarding fatty acids, the digestive gland clearly reflected dietary lipid and fatty acid profile, while muscle showed a more stable composition. Low dietary ARA content reflected in octopus tissues, especially in specimens fed on DB‐based diets, which did not seem to affect growth during the experimental period.

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This is the peer reviewed version of the following article: Roo, J., Estefanell, J., Betancor, M. B., Izquierdo, M., Fernández-Palacios, H. and Socorro, J. (2017), Effects of supplementation of decapod zoea to Artemia basal diet on fatty acid composition and digestive gland histology in common octopus (Octopus vulgaris) paralarvae. Aquac Res,, which has been published in final form at https://doi.org/10.1111/are.12910. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving. The present study aimed to evaluate the effect of the supplementation of different crab 21 zoeas to enriched Artemia basal diet for O. vulgaris paralarvae during the first month of 22 life. Paralarvae were fed using: enriched Artemia nauplii alone and Artemia co-fed with 23 either first zoea stages of Grapsus adscensionis or Plagusia depressa. The experiment 24 was carried out over a period of 28 days, in 0.12 m 3 tanks with a flow-through rearing 25 system. Growth in dry weightas well as mantle length and width were assessed weekly. 26 Effects of supplementation of decapods zoea toAdditionally, prey and paralarvae fatty acid composition and digestive gland (DG) 27 histology were evaluated. Addition of low amounts of crab zoeas (approx.100 indv. L enriched Artemia. These results were supported by the finding of a higher number of 31 glycoprotein absorption vacuoles in the DG from paralarvae co-fed with crab zoeas, 32 suggesting a higher feeding activity. In addition, the fatty acid analysis of crab zoea 33showed that these are good sources of dietary arachidonic and eicosapentaenoic acids 34 during the octopus planktonic life stage, whereas the low docosahexaenoic (DHA) 35 content, suggests the use of additional DHA sources or higher zoeas densities to meet 36 paralarvae nutritional demand to carry out a successful metamorphosis to benthic life. Although the first studies on O. vulgaris paralarvae culture were conducted more than 56 30 years ago, the development of the farming industry is still mainly constrained by the 57 lack of a sustainable supply of reared juveniles; with high paralarvae mortality during 58 the early stages its main bottleneck (Iglesias et al. 2007 Thus, the present study aimed to evaluate the effects of supplementation of crab zoeas 114to Artemia basal diet on the biological performance and nutritional status of octopus 115 paralarvae during the critical time window of specialized prey selection at the first 116 month of life. To achieve so, O. vulgaris paralarvae were fed three diets containing Three Canaria 15 days before the trial started until the end of the experimental period. Gravid 164 specimens were caught using a traditional fishing methodology consisting of a fishing 165 rod with a ball of fishing line wrapped around the tip with a piece of bait (sardines) 166 inserted. Crabs attracted to the bait were rolled in the fishing line, allowing their 167 capture. Only ovigerous females were selected and stocked in separated 1.5 m 3 fibre 168 glass tanks...

Octopus vulgaris is a species of demand in the market with the potential to diversify European aquaculture. However, this species develops complex social interactions under culture conditions, which may have negative e¡ects on its growth, survival and pro¢tability. In order to understand its behaviour under such conditions, individual tagging systems allow a careful evaluation of biological parameters, such as growth and longevity. The present work describes a combined protocol (anaesthetic and tagging) for implanting subcutaneous passive integrated transponder tags (PIT). The e¡ect of two anaesthetic agents in facilitating octopus handling is assessed: clove oil at 20^40^100 mg L À 1 and ethanol (96%) at 1^1.5^2%. The most suitable body location of PIT tags, its e¡ect on growth and mortality, the addition of a stitch and the PIT retention rate after 2 months in £oating cages were evaluated. It was concluded that immersion in seawater with 1.5% of ethanol at 22.3 AE 0.5 1C is a suitable anaesthetic for this species. The results showed that the best-selected PIT body location was the upper left arm III. No e¡ect of the PIT tagging system was found on growth and survival when tagged and untagged octopuses were compared. It was observed after 2 months that the stitch did not induce an increase in the retention rate and 81^100% tag retention regardless of the dietary treatment.