Crecimiento individual de Octopus vulgaris (Cuvier, 1797) alimentado con pienso húmedo experimental y boga (Boops boops, L. 1758)

[EN]The present work pretends to be the first step towards the development of a commercial diet for Octopus vulgaris. A one month experiment evaluated growth on two treatments, a wet experimental diet and a control (bogue), obtaining a daily growth rate of 1,6 and 16 g/day respectively. Octopuses were tagged and a better growth tendency was found in middle size animals in each experimental tank

Engorde de pulpo común Octopus vulgaris en jaulas en la comunidad Canaria [Material gráfico] [Recurso electrónico] : efecto de la dieta y la densidad inicial

Octopus vulgaris on-growing in floating cages is a promising activity implemented in Spain at industrial level, with productions of 16-32 tons/year from 1998. Nevertheless, some aspects of the culture system need to be evaluated to warrantee its profitability. In the present work absolute growth rate (AGR, g/day) and mortality (%) under two initial rearing densities, 10 and 17 kg/m3, were compared under two feeding regimes over 15 weeks. One diet was composed by bogue, supplied as ?discarded? species from local fish farms. The other diet was based on a 40-60% discarded bogue-crab Portunus pelagicus. Half of the reared octopuses were PIT-tagged and two sampling points were established along the experimental period. Regardless of dietary treatment, up to the 11th week, growth was 19 and 13 g./day for the low and high rearing density. On the other hand, up to the 11th week mortality was higher in the control diet fed group (30%), reaching 74-84% by the end of the experiment regardless of rearing density and dietary treatment, which could suggest some nutritional imbalance of the tested diets.

Pre-engorde de pulpo común Octopus vulgaris con 3 dietas basadas en descartes de acuicultura en la comunidad Canaria

On-growing of Octopus vulgaris fed different feeds has shown promising results. Nevertheless, since the minimum legal size for octopus fisheries in spain i sin most of experimental ongrowing of this species an average weight over 750-1000kg was utilized with g (and little research has been conducted in order to evaluate the effect of these diets on smaller individuals. The present work evaluates the effect of 3 diets based on bogue, obtained as ?discarded? species from local fish farms, on ingestion and growth of O. vulgaris weighing 400 g. The 1st diet was composed by discarded bogue, the 2nd diet by a 40-60% discarded bogue-crab Portunus pelagicus and the 3rd diet was presented as a moist diet based on discarded bogue. A triplicate of four octopuses per treatments, male:female 1:1, were kept in circular 400 l tanks and fed each diet for 4 weeks. Absolute growth rate (AGR, g./day), standard feeding rate (SFR, %/day) and feed efficiency (FE) were calculated. The addition of crab to the diet increased SFR which underlines different feeding habits when compared with 0.8-1 kg octopuses. Lower growth and higher FE was recorded with the moist diet, probably due to high disintegration of this kind of feed.

Effect of different live prey, Grapsus grapsus Linnaeus 1758 and Plagusia depressa Fabricius, 1775 zoeas,over histology and biochemical composition of common octopus, octopus vulgaris Cuvier, 1797 paralarvae

[EN] Since paralarval rearing is still the main bottleneck for the development of octopus culture, the aim of the present study was to obtain some information on the feeding strategy and nutritional requirements during paralarval stage. For that purpose just hatched out octopus paralarvae were fed with live preys in three different combinations, trying to match their natural food: Enriched Artemia metanauplii, Grapsus grapsus zoeas supplemented with enriched Artemia, and Plagusia depressa zoeas supplemented with enriched Artemia. Paralarval treatments were carried out during 28 days in triplicates; fibre glass 120 l tanks in flow through system were used. Growth, in terms of dry body weight, mantle length and width, was determined each seven days. A histological study of the paralarval development was carried out. Biochemical composition of preys and paralarvae were determined. Growth was significantly better in paralarvae fed with zoeas and Artemia than in those fed only with Artemia, from day 8 after hatching. Besides a clear effect on the digestive gland histology morphology was observed.