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Browsing by Author "Navarro, Juan C."

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  • Comparative study on fatty acid metabolism of early stages of two crustacean species: Artemia sp. metanauplii and Grapsus adscensionis zoeae, as live prey for marine animals
    Publication . Reis, Diana; Acosta, Nieves G.; Almansa, Eduardo; Navarro, Juan C.; Tocher, Douglas R.; Andrade, José Pedro; Sykes, António V.; Rodríguez, Covadonga
    The present study compared the lipid composition and in vivo capability of Artemia sp. metanauplii (the main live prey used in aquaculture) and Grapsus adscensionis zoeae (as a wild zooplankton model) to metabolise unsaturated fatty acids. The two species were incubated in vivo with 0.3μM of individual [1-14C]fatty acids (FA) including 18:1n-9, 18:2n-6, 18:3n-3, 20:4n-6 (ARA), 20:5n-3 (EPA) and 22:6n-3 (DHA) bound to bovine serum albumin (BSA). Compared to metanauplii, zoeae contained twice the content of polar lipids (PL) and eight-fold the content of long-chain polyunsaturated fatty acids (LC-PUFA). Artemia sp. metanauplii showed increased short chain fatty acid de novo synthesis from beta-oxidation of [1-14C]LC-PUFA, preferentially DHA. Of the LC-PUFA, DHA showed the highest esterification rate into Artemia sp. triacylglycerols. In contrast, in Grapsus zoeae [1-14C]DHA displayed the highest transformation rate into longer chain-length FAs and was preferentially esterified into PL. EPA and ARA, tended to be more easily incorporated and/or retained than DHA in Artemia sp. Moreover, both EPA and ARA were preferentially esterified into Artemia PL, which theoretically would favour their bioavailability to the larvae. In addition to the inherent better nutritional value of Grapsus zoeae due to their intrinsic lipid composition, the changes taking place after the lipid incorporation, point at two distinct models of lipid metabolism that indicate zoeae as a more suitable prey than Artemia sp. for the feeding of marine animals.
    2017Journal article Restricted Show more
  • Meta-analysis approach to the effects of live prey on the growth of octopus vulgaris paralarvae under culture conditions
    Publication . Garrido, Diego; Martín, Virginia M.; Rodríguez, Covadonga; Iglesias, José; Navarro, Juan C.; Reis, Diana; Riera, Rodrigo; Sykes, António V.; Almansa, Eduardo
    The common octopus (Octopus vulgaris, Cuvier 1797) is a species with increasing interest for marine aquaculture diversification, given its high growth rate and easy adaptation to captivity, among other positive features (Iglesias et al. 2007, 2014a). However, the massive paralarvae mortalities verified under culture conditions ( 100% in most studies) have hampered its commercial production, therefore making this the main bottleneck for industrial farming. According to several authors (Iglesias et al. 2007, 2014a; Iglesias & Fuentes 2013), the high mortalities could be due to: (i) inadequate and/or unbalanced diets that do not fulfil paralarvae nutritional requirements, (ii) lack of standardized rearing techniques, and (iii) little knowledge about octopus paralarvae physiology and behaviour.
    2016Journal article Restricted Show more