Browsing by Author "Figueiredo, Filipe"
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- Optimizing rearing and welfare in Senegalese sole (Solea senegalesensis) broodstock: effect of ambient light intensity and handling time on stress responsePublication . Figueiredo, Filipe; Aragão, Cláudia; Pinto, Wilson; Dinis, Maria Teresa; Oliveira, CatarinaBroodstock rearing conditions and handling procedures should be optimized in aquaculture species in order to benefit fish welfare and guarantee optimal conditions for spawning. In teleosts, basal cortisol levels display daily rhythms, oscillating along the 24 h of the day. In this sense, handling fish at different moments of the day may lead to different stress responses. The present study aimed at investigating the optimal rearing conditions for Senegalese sole broodstock, considering ambient light intensity and handling time. The optimal light intensity (50, 100 or 200 lx) was investigated by measuring fish cortisol levels and monitoring locomotor activity rhythms under each intensity tested. Results showed a significant increase in cortisol levels of fish exposed to 200 lx, when compared to values obtained under 100 lx, accompanied by changes in locomotor activity rhythms in both tanks under study. These results suggested that 200 lx may be too high as light intensity for this species, whereas 100 lx seems to be more adequate. Also, daily rhythms of stress response were investigated in breeders from different origins (Wild and first generation, G1). Basal cortisol levels and cortisol stress response after an acute stressor (air exposure) were monitored at two distinct moments of the day (Mid-Light and Mid-Dark). Basal levels were higher during the day in the wild group, while G1 fish seemed to have lost the daily fluctuations in basal cortisol plasma levels, as well as their daily rhythms of locomotor activity. Both groups showed lower stress responses during night-time, an indication that this is an adequate period of the day to handle this species. Senegalese sole breeders born in captivity presented more pronounced stress responses when compared to wild fish, reflecting their different life history in terms of stress challenges.
- Polyunsaturated fatty acids of marine macroalgae: potential for nutritional and pharmaceutical applicationsPublication . Pereira, Hugo; Barreira, Luisa; Figueiredo, Filipe; Custodio, Luisa; Vizetto-Duarte, Catarina; Polo, Cristina; Resek, Eva; Engelen, Aschwin; Varela, JoaoAs mammals are unable to synthesize essential polyunsaturated fatty acids (PUFA), these compounds need to be taken in through diet. Nowadays, obtaining essential PUFA in diet is becoming increasingly difficult; therefore this work investigated the suitability of using macroalgae as novel dietary sources of PUFA. Hence, 17 macroalgal species from three different phyla (Chlorophyta, Phaeophyta and Rhodophyta) were analyzed and their fatty acid methyl esters (FAME) profile was assessed. Each phylum presented a characteristic fatty acid signature as evidenced by clustering of PUFA profiles of algae belonging to the same phylum in a Principal Components Analysis. The major PUFA detected in all phyla were C-18 and C-20, namely linoleic, arachidonic and eicosapentaenoic acids. The obtained data showed that rhodophytes and phaeophytes have higher concentrations of PUFA, particularly from the n-3 series, thereby being a better source of these compounds. Moreover, rhodophytes and phaeophytes presented. healthier. Sigma(n-6/)Sigma(n-3) and PUFA/saturated fatty acid ratios than chlorophytes. Ulva was an exception within the Chlorophyta, as it presented high concentrations of n-3 PUFA, alpha-linolenic acid in particular. In conclusion, macroalgae can be considered as a potential source for large-scale production of essential PUFA with wide applications in the nutraceutical and pharmacological industries.
- Sustainable valorization of halophytes from the Mediterranean area: a comprehensive evaluation of their fatty acid profile and implications for human and animal nutritionPublication . Vizetto-Duarte, C; Figueiredo, Filipe; Rodrigues, Maria João; Polo, Cristina; Rešek, Eva; Custódio, LuísaHalophytic plants can provide an economical and environmentally sustainable source of products for human and animal feeding, in the context of the increase of worldwide emergent semi-arid landscapes. This work reports a comprehensive evaluation of the qualitative and quantitative composition of fatty acids (FA) of nineteen Mediterranean halophytes collected in southern Portugal, with the purpose of establishing their possible uses as food and feed. For FA determination, lipids and free FA were converted to the corresponding fatty acid methyl esters (FAME) and analyzed by GC-MS. Beta maritima had the highest FAME levels (7.3 mg/g DW) while Suaeda vera had the lowest content (1.0 mg/g DW). The most common saturated fatty acid (SFA) across all studied species was palmitic acid. The most prevalent monounsaturated fatty acid (MUFA) was oleic acid. Polyunsaturated fatty acids (PUFA) levels were led by linoleic acid. Less common FAMEs were also detected, namely eicosadienoic and hexadecatrienoic acids. Cotula coronopifolia, Phragmites australis and Suaeda vera displayed the best FA nutritional profiles. These species also showed bioactivities relevant for both human and animal health according to the literature and thus, collectively with this study, they could be further explored as food and feed.