Is Copper Supplementation Required in Formulated Feeds forOctopus vulgaris(Cuvier, 1797)?

Abstract

The aim of this study was to test the effect of copper supplementation in a formulated feed on the growth, feed efficiency, and nutritional composition of subadults Octopus vulgaris, with particular reference to the differences in the content of copper in the tissues (muscle, digestive gland, and hemolymph). Two formulated feeds were supplied to subadults octopuses kept individually for 56 days: Basal diet [11.6 mgCu/kg dry weight (dw)], and another feed with a similar composition but including a copper supplementation (copper diet: 115.2 mgCu/kg dw). No significant differences (P > 0.05) were detected in the respective growth rates (0.88% body weight/day), FE (79.5%-82.1%), proximate composition, hemolymph hemocyanin (1.6-1.8 mmol/L), hemolymph copper (0.19-0.20 mgCu/mL), or muscle copper levels (22.7-23.2 mgCu/kg dw). No significant changes were detected on proximate composition, hemocyanin and hemolymph, and muscle copper levels between animals fed formulated feeds and an initial group fed natural diet based on crab and fish (P > 0.05). The only parameter which showed a significant difference (P < 0.05) was the copper level in the digestive gland: 1,797, 390, and 1,148 mgCu/kg dw for initial (natural diet), basal and copper diet, respectively (P < 0.05). Considering the experimental conditions of this study, copper supplementation is not effective in improving the performance of a formulated feed for octopus.

Acute-Stress Biomarkers in Three Octopodidae Species After Bottom Trawling

“…Supporting this idea, some studies conducted in cuttlefish ( Sepia officinalis ) embryo shown increased PO activity after exposure to dissolved metals (Lacoue-Labarthe et al, 2009), while O. vulgaris infected by a protozoan parasite show changes in blood Hc (Castellanos-Martinez et al, 2014). In the present study, plasma Hc reached stable values circa 1–1.5 mM in all animals after 24 h recovery, similar to those levels described in several cephalopod species (Senozan et al, 1988; Aguila et al, 2007; Sancho et al, 2015; Roumbedakis et al, 2017). Our hypothesis that Hc acts as a total PO-like enzyme in octopus is based in the fact that after bottom trawling E. moschata and O. vulgaris had 60–80% less Hc and pro-PO activity than 24 h later, when recovered.…”

“…Animals were anesthetized by decreasing water temperature to circa 4°C (by covering the aquariums with ice for 5 min, without physical disturbance of the animals) and addition of 2.5% ethanol for 2 min after that, conforming the principles of Directive 2010/63/EU, and following described procedures (Malham et al, 2002; Estefanell et al, 2011; Sancho et al, 2015). Haemolymph samples were taken with sterile 1 mL 25 G syringes (circa 300 μL per animal) from the principal heart as described before (Aguila et al, 2007).…”

Performance of Marine Lecithin Supplemented Feeds for the Common Octopus (Octopus vulgaris) Ongrowing: Changes in Proximate Composition and Lipid Classes’ Profile

“…Altogether, these results might suggest that O. vulgaris has a limited tolerance to high-lipid feeds during prolonged periods, as the two referred studies (Morillo-Velarde et al [10] and Rodríguez-González et al [54]) and the present showed this FE reduction and share the commonality of feeding octopus on high-lipid diets. The higher metabolic effectiveness of smaller animals, compared with bigger ones, should also explain the decrease in FE during the second month [6,58]. Although the individuals used in the experiment were males (known to be less affected by reproduction processes), maturation could also have affected FE.…”

Aquarium Maintenance Related Diseases

“…This is probably due to this metal either triggering or inhibiting the phenoloxidaselike activity, which is implicated in the innate immune system (Lacoue-Labarthe et al 2009). On the other hand, 6 ppm of copper in seawater (used as a way to increase the availability of this trace element) has been used in O. vulgaris paralarvae rearing (Garrido et al 2014) or even up to 115 ppm in formulated feeds for juveniles of this same species (Sancho et al 2015) without deleterious effects. The differences found between S. officinalis and O. vulgaris might be due to the possibility of this trace element being essential for the proper development of the latter, as suggested by Villanueva and Bustamante (2006) and García--García and Cerezo-Valverde (2006).…”