Biological performance ofOctopus vulgarisin ‘integrated aquaculture’ models: effect of two potential fresh diets, sex and sexual maturation during the grow-out phase

Abstract

Two fresh diets were tested on the biological performance of males and females of Octopus vulgaris under industrial rearing conditions in floating cages. The presence of females could potentially release paralarvae to the natural environment (‘integrated aquaculture’). Octopuses were fed on a single diet of bogue (aquaculture by‐product), and on a mixed diet (60–40% crab‐bogue), in two trials. In Trial 1 (918 ± 125 g), growth was higher in octopuses fed on the mixed diet (1.9–2.0%d−1) than in those fed on the bogue diet (1.8–1.9%d−1) irrespective of sex, and mortality was 3% regardless of sex and diet. In Trial 2 (1483 ± 269 g), growth was higher in males fed on the mixed diet (1.8%d−1) than in males fed on the bogue diet (1.4%d−1), both higher than females (1.1–1.3%d−1), and mortality was 22–28% regardless of sex and diet. Best biological performance in trial 1 was related to the lack of functional maturation in females, evidence by the low average gonadosomatic index (2.0–3.6%) in comparison with trial 2 (8.8–11.4%), regardless of diet. No correlations between final weight and sexual maturity indices were found, so the length of the rearing period to maximize biomass increment or to release paralarvae depends on functional maturation in females.

Effect of two fresh diets and sexual maturation on the proximate and fatty acid profile of several tissues inOctopus vulgaris: specific retention of arachidonic acid in the gonads

“…; Estefanell et al . ). GSI values were higher than in previous data collected from wild specimens (Rosa et al .…”

“…This study intends to evaluate the effect of two fresh diets on the biochemical composition of several tissues in O. vulgaris, reared in sea cages for 2 months. Biological data of this study (growth, mortality, conversion rates) were already published and discussed elsewhere (Estefanell et al 2012d). Both diets, bogue (aquaculture by-product) as a single diet or complemented with crab Portunus pelagicus, were previously tested in individually reared males of O. vulgaris, to evaluate their effect on the biochemical profile of muscle and digestive gland (Estefanell et al 2011b).…”

“…Wild octopuses were caught by professional fishermen, transported to laboratory facilities and acclimatized in the . . conditions described in the study described by Estefanell et al (2012d). One week after arrival, each octopus was individually tagged on upper left arm III with a passive integrated transponder (PIT; Estefanell et al 2011a).…”

“…This study was performed in two stainless steel floating cages (1.5 9 3 9 1.5 m length, depth and width, respectively), with approximately 5 m 3 of water capacity, enclosed with galvanized steel net of 2 cm mesh (Estefanell et al 2012d). Shadowing nets and 90 'T' shaped PVC tubes (160 mm diameter) were added to each cage.…”

Performance of raw material thermal treatment on formulated feeds for common octopus (Octopus vulgaris) ongrowing

“…However, crustaceans are highly priced and its use would raise the price of produced octopus. Therefore, some fish species, such as bogue (Boops boops) rejected from aquaculture production, have been used in commercial ongrowing García García and Cerezo Valverde, 2006;Sánchez et al, 2014) and in octopus diet formulations Estefanell et al, 2013Estefanell et al, , 2014.…”