Efficient utilization of dietary lipids inOctopus vulgaris(Cuvier 1797) fed fresh and agglutinated moist diets based on aquaculture by-products and low price trash species

Abstract

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.

Fatty Acid Profile of Neutral and Polar Lipid Fraction of Wild Eggs and Hatchlings from Wild and Captive Reared Broodstock of Octopus vulgaris

“…In our study, hatchlings obtained from captive broodstock showed a significantly different proportion of polar and neutral lipids and deviations in the fatty acid profile in comparison with wild ones, probably related to the broodstock diet (Quintana et al, 2015). The bogue Boops boops used as food shows high DHA and linoleic acid and low ARA content (Estefanell et al, 2012b), mainly provided as triglycerides (neutral lipids) (Cerezo Valverde et al, 2012). In captive hatchlings, the neutral fraction fatty acid profile was relatively similar to wild hatchlings.…”

Digestive Physiology of Octopus maya and O. mimus: Temporality of Digestion and Assimilation Processes

“…For cephalopods, in particular for octopus, proteins are the main metabolic substrate characterized by a natural diet based mainly on crustaceans, molluscs, and fish (Alejo-Plata et al, 2009; Krstulovíc and Vrgoc, 2009; Estefanell et al, 2013). Previous studies have demonstrated the importance of crustaceans in octopus diets, showing that up to 19 crustaceans species can be found in the diet of wild Octopus vulgaris paralarvae (Roura et al, 2012).…”

“…For wild sub-adults of O. vulgaris , it was recently demonstrated that dehydration of raw materials at temperatures lower than 60°C induced similar growth rates when compared to freeze dried ingredients (Rodriguez-González et al, 2015), indicating that protein characteristics are correlated with the digestive capacity of the animals. Although, there are many papers related to important ingredients (amino acids, lipids) for O. vulgaris feed (Cerezo-Valverde et al, 2012a,b, 2013; Estefanell et al, 2013; Querol et al, 2013; Hamdan et al, 2014; Rodriguez-González et al, 2015) there is a general lack of knowledge of the physiological processes involved during nutrient digestion in octopus species. Considering that protein digestion is a key aspect of cephalopod nutrition, the study of the process by which proteins (and other nutrients) are digested and assimilated will determine diet design (Martínez et al, 2014).…”

Artificial marine habitats favour a single fish species on a long-term scale: the dominance of <em>Boops boops</em> around off-shore fish cages

“…Even artisanal fisheries shifts are related to these aggregations in the Canary archipelago. For example, the bogue was considered a fishery resource of secondary importance or even used as bait for several tuna species and for experimental octopus culture (Estefanell et al 2011). However, the bogue is currently considered one of the main catches by artisanal fisheries in the study area (NE Tenerife), with catches of around 800 kg/year (data from fisherman's association in the study area).…”

“…In the Canary Islands the bogue has been traditionally fished to use as live bait for tuna (e.g. skipjack, Katsuwonus pelamis) (Ramos et al 1995) and it has recently been used as a component of octopus diet in reared conditions (Estefanell et al 2011). Therefore, this is of some ecological and economic importance for Canary coastal habitats.…”