Browsing by Author "Riera, Rodrigo"
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- A baseline for prioritizing the conservation of the threatened seagrass Cymodocea nodosa in the oceanic archipelago of MadeiraPublication . Ribeiro, Cláudia; Neves, Pedro; Kaufmann, Manfred; Araújo, Ricardo; Riera, RodrigoSeagrasses are experiencing fragmentation and regression globally; thus, protection and recovery of meadows are a preservation priority. However, conservation actions must consider inherent regional conditions, since certain coastal areas are not suitable for the settlement of extensive meadows. Likewise, small oceanic archipelagos are not always able to fulfil the habitat requirements of seagrass habitats but can harbour small patches that in turn provide unique research opportunities. In this study, we focused on the seagrass Cymodocea nodosa in the archipelago of Madeira (NE Atlantic Ocean). Here we compile historical and contemporary records of this species along with characterization of associated communities (fish and invertebrates). A bionomic map with potentially suitable areas for the establishment and settlement of this species is also included. Lastly, we highlight coastal management and restoration actions and future research directions to preserve this species in Madeira Island.
- Characterization of deformed hatchlings of Octopus vulgaris obtained under captivity from a small femalePublication . Jiménez-Prada, Pablo; Scherbakova, Anastasia; Riera, Rodrigo; Felipe, Beatriz C.; Sykes, António V.; Gonçalves, Rui A.; Andrade, José Pedro; Perales-Raya, Catalina; Rodríguez, Covadonga; Almansa, EduardoThe common octopus (Octopus vulgaris), a promising species for aquaculture, spawns easily under cap-tivity from mature females (usually above 1 kg wet weight). Octopus juveniles and adults are collectedfrom nature to obtain eggs and paralarvae for aquaculture development trials. In July 2011, a very smallfemale (150 g wet weight but with an age estimation of 300 days-old) spawned almost 77,000 paralar-vae. Malformations of paralarvae were noticed in the first spawning days, namely the absence of arms.Despite not being lethal, these abnormalities might be derived from the physiological condition of thebreeding specimen (the female’s lower weight to the estimated amount of living days), which might beeventually related to nutritional unbalances or genetic parameters that were transferred to the eggs.
- Effects of feeding with different live preys on the lipid composition, growth and survival ofOctopus vulgarisparalarvaePublication . Reis, Diana B.; Shcherbakova, Anastasia; Riera, Rodrigo; Martín, M. Virginia; Domingues, Pedro; Andrade, Jose; Jimenez-Prada, Pablo; Rodriguez, Covandonga; V. Sykes, Antonio; Almansa, EduardoTo move forward in the farming ofOctopus vulgarisparalarvae, it is necessary to search for a live prey easy to obtain and maintain in the laboratory that meets the nutritional requirements of the octopus paralarvae and adapts to its predatory behaviour.Grapsus adscensioniszoeae (Crustacea, Decapoda) seems to fulfil most of these targets, and it was herein used to deepen knowledge of paralarvae lipid requirements and composition, growth and survival. To this purpose, the effects of feeding withGrapsuszoeae as sole prey were compared withArtemiaat two different stages (nauplii and juveniles), which also differed in their lipid profiles. After 15 days of feeding, the best growth and survival of paralarvae was obtained in theGrapsusgroup, and no differences were observed between bothArtemiagroups. Triacylglycerides storage in paralarvae seemed to be co-related with a lower growth and survival, but not with its prey levels. Contrarily, sterol ester levels were higher in paralarvae fedGrapsus, reflecting its content in the prey. The best paralarval viability was related to higher levels of 22:6n-3 (DHA) and 20:4n-6 (ARA), also reflecting its higher content in the prey. On the other hand, neither the 20:5n-3 (EPA) levels in the prey nor in paralarvae were related to growth or survival. The implications of these results are discussed considering the lipid requirements ofO. vulgarisparalarvae.
- Meta-analysis approach to the effects of live prey on the growth of octopus vulgaris paralarvae under culture conditionsPublication . Garrido, Diego; Martín, Virginia M.; Rodríguez, Covadonga; Iglesias, José; Navarro, Juan C.; Reis, Diana; Riera, Rodrigo; Sykes, António V.; Almansa, EduardoThe 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.