6 resultados para comunidad local
em Acceda, el repositorio institucional de la Universidad de Las Palmas de Gran Canaria. España
Resumo:
Programa de Doctorado: Fuentes, Métodos e Historiografía para la Investigación en el Mundo Atlántico
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Máster Oficial en Gestión Costera
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[EN] Los análisis genéticos de las estrategias reproductivas (paternidad múltiple y almacenamiento de esperma) están abriendo una vía de investigación novedosa además de promover informaciones importantes para definir los criterios y las medidas de conservación de muchas especies de reptiles. La población de tortuga común, Caretta caretta del Archipiélago de Cabo Verde es una de las poblaciones nidificantes más grandes del Atlántico, pero que actualmente sufre la pesca selectiva de machos por parte de la comunidad local de Cabo Verde. En este estudio se pretende testar la hipótesis de que una disminución significativa en el número de machos podría afectar la eficacia biológica de las crías, disminuyendo la variabilidad genética de la población.
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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.
Resumo:
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.
Resumo:
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 study two rearing systems and two dietary treatments were evaluated. Individual and group rearing, in PVC net compartments and floating cages respectively, were compared under two dietary treatments. One diet was composed by bogue, supplied as ?discarded? species from local fish farms, and the other was based on a 40-60% discarded bogue-crab Portunus pelagicus. All octopuses were PIT-tagged and the experiment lasted two months. Animals were sampled once throughout the experimental period and absolute growth rate (AGR, g./day) and mortality (%) were calculated. AGR of group rearing was above 30 g./day, however individual rearing showed 100% survival so biomass increment was higher. On the other hand, males grew more than females regardless of dietary treatment.