Browsing by Author "Andrade, Carlos"
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- Effects of feeding levels on growth response, body composition, and energy expenditure in blackspot seabream, pagellus bogaraveo, juvenilesPublication . de Almeida Ozorio, Rodrigo Otavio; Andrade, Carlos; Freitas Andrade Timoteo, Viriato Manuel; Eugénio Castanheira Conceição, Luis; Pinheiro Valente, Luisa MariaAlthough reported as a slow growing species, to date information regarding nutritional dynamics of blackspot seabream, Pagellus bogaraveo, is limited, especially during ongrowing phase. This study determined the effects of different feeding levels on growth response, body composition, and energy expenditure of blackspot seabream juveniles (initial weight = 64 g). Fish were allocated in nine indoor tanks (15 fish per tank) and fed a basal diet twice daily at increasing levels (2.5, 3.3, and 4.1 g feed/kg(0.8)/d) for 138 d. Growth response decreased with decreasing feeding levels, but only at 2.5 g feed/kg(0.8)/d (P < 0.001). Differences in growth rates were positively correlated with body lipid content (r(2) = 0.90). Net protein utilization decreased with each increase in feeding level. The energy requirement for zero growth (maintenance) and the estimated energy loss on starvation were calculated as 22.6 and 17.9 kJ/kg(0.8)/d, respectively. The energy cost for protein and lipid gain was calculated as 3.8 and 1.4 kJ/kJ energy deposited, respectively. This study suggested that blackspot seabream may grow slower than the other close-related species because of its higher demand of dietary protein energy in favor of lipid deposition.
- Exploring the potential of wine industry by-products as source of additives to improve the quality of aquafeedPublication . Camara, Jose S.; Lourenco, Silvia; Silva, Catarina; Lopes, André; Andrade, Carlos; Perestrelo, RosaThe recent growing concern driven by consumer interest in the safety and quality of seafood, has boosted the search for healthy and functional aquafeeds. The current study represents the first approach to assess the potential of volatile composition of the wine industry by products (e.g., grape pomace, grape stems, lees), as additives for improving the quality of fish feeds in terms of organoleptic characteristics (e.g., aroma and flavor) and health benefits. Headspace solid-phase microextraction followed by gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to establish the volatile profile of wine industry by-products. A total of 153 volatile organic compounds (VOCs), which belong to different chemical families, comprising 36 esters, 31 carbonyl compound, 20 alcohols, 18 terpenoids, 17 acids, 11 furanic compounds, four volatile phenols, two lactones, and 14 miscellaneous, were identified. Esters and terpenoids showed a positive contribution to the aquafeeds aroma with fruity, sweet, green, fresh, and berry notes, whereas some acids (e.g., hexanoic acid) and terpenoids (e.g., limonene) could be used as antimicrobial, antioxidant and antiproliferative agents. Our findings confirmed the potential of wine industry by-products as a rich source of essential compounds to enhance the quality of aquafeeds towards the valorization of winery waste based on the concept of circular economy. Further investigation on the extraction, isolation and purification of VOCs from a natural bio-source will guarantee the safety of the aquafeed and compliance with the requirements of the animal feed industry.
- Population density, reproduction cycle and nutritional value of Sphaerechinus granularis (Echinodermata: Echinoidea) in an oceanic insular ecosystemPublication . Lourenço, Sílvia; José, Ricardo; Neves, Pedro A.; Góis, André; Cordeiro, Nereida; Andrade, Carlos; Ribeiro, CláudiaSea urchins play an important role in island coastal ecosystems as keystone species and as potential resources for harvesting and aquaculture. In Southern Europe, the most valuable and harvested species is the European purple sea urchin Paracentrotus lividus, but there is a growing interest to explore other edible species like the blunt sea urchin Sphaerechinus granularis. The echinoderms biodiversity of Madeira archipelago was previously described, but their local habitat, population densities and size distribution, important to establish their harvest and aquaculture potential, are poorly known. The present study aimed to evaluate S. granularis population in the oligotrophic and narrow insular shelf of Madeira archipelago, mainly regarding its habitat, densities, reproduction season and roe marketable characteristics. Sphaerechinus granularis was found in low densities (0.01 ind./m(2)) from shallow to deep reefs (5-30 m). The highest densities occurred in shallow waters and breakwaters in association to encrusting algae, turf and erect brown macroalgae. Here, the low primary productivity ecosystem influenced the long reproductive season of the local population. This population showed a relatively high gonadosomatic index (maximum GI of 8), high gonad weight (5.00-12.19 g) with high proportion of bright yellow and orange gonads (37.5-60%) between February and November. Additionally, the high level of total carotenoids, the high PUFA (particularly EPA) content, and the ratio n-6/n-3 close to one support the high nutritional value of S. granularis roe. The trend of incremental GI between September and November and the increasing content of PUFA in autumn suggests this could be the preferential harvesting season. This information is key to evaluate a sustainable exploitation of this living marine resource.