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Research Project
Sea cucumbers: the new resource for a hungry fishery (CUMFISH)
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Seagrass debris as potential food source to enhance Holothuria arguinensis' growth in aquaculture
Publication . Dominguez Godino, Jorge Antonio; Santos, Tamara; H., Pereira; Custódio, Luísa; Gonzalez-Wanguemert, Mercedes
Holothuria arguinensis aquaculture started to be developed in 2014, being the first sea cucumber species from Europe. However, some aspects of its aquaculture biotechnology, such diets, need to be assessed. This work aimed to evaluate seagrass debris of Zostera noltii and Cymodocea nodosa as food source for broodstock maintenance in tanks, during breeding periods. The given feed rations per tank were calculated as the 30% of the total sea cucumber biomass in each tank and reviewed each week. Then, feed rations of seagrass and sediment were calculated from this value, according to the following percentages: 40% sediment, 15% Z. noltii, 40% Z. noltii, 15% C. nodosa and 40% C. nodosa. H. arguinensis growth, feeding rate and nutritional value were assessed under these diets. H. arguinensis fed with 40% of Z. noltii showed the highest growth (specific growth rate = 0.09 +/- 0.06%/day, absolute growth rate = 0.11 +/- 0.07 g/day) increasing their final weight in 5.86 +/- 3.57% in 57 days. However, the individuals fed with C. nodosa showed a negative growth. H. arguinensis showed a reduction in its feeding rate as the organic matter content in the diets increased. H. arguinensis did not show any important change on proximate composition, protein, lipid, mineral contents and fatty acids profile among the feeding groups, or in comparison with the individuals collected from wild habitat. Therefore, H. arguinensis could be fed with Z. noltii debris during tanks maintenance along breeding period, ensuring its growth and maintaining its nutritional profile.
Sea cucumbers, Holothuria arguinensis and H-mammata, from the southern Iberian Peninsula: variation in reproductive activity between populations from different habitats
Publication . Marquet, Nathalie; Conand, Chantal; Power, Deborah; Canario, Adelino; Gonzalez-Wanguemert, Mercedes
New fisheries in the western Mediterranean and north eastern Atlantic target the sea cucumbers Holothuria arguinensis and H. mammata; however, lack of biological information hinders management decisions. Here, the reproductive biology of populations the two species was investigated in the southern Iberian Peninsula. Different populations located along a narrow latitudinal range displayed the same general reproductive pattern of summer-autumn spawning. However, significant differences in size, gonadal production and maturity profile between locations suggests the influence of site-specific factors. In Sagres and Ria Formosa H. arguinensis individuals were larger and had larger gonads than in Olhos de Agua, which had relatively more immature animals. The spawning and active gametogenesis periods were also longer in Sagres, possibly linked to specificity of food availability and tidal conditions. Ria Formosa also had larger H. mammata individuals with larger gonads than in Murcia and Olhos de Agua, possibly reflecting differences in feeding activity in different substrates (muddy/sandy vs rocky). Gametogenesis in H. arguinensis may be triggered by decreasing photoperiod and temperature, and spawning by increasing temperature. Altogether, these results, which include fecundity and size at first maturity, provide an important basis for the scientific management of sea cucumber fisheries in the region. (C) 2017 Elsevier B.V. All rights reserved.
Assessment of Holothuria arguinensis feeding rate, growth and absorption efficiency under aquaculture conditions
Publication . DOMINGUEZ GODINO, JORGE ANTONIO; Gonzalez-Wanguemert, Mercedes
Holothuria arguinensis is a potential species for sea cucumber aquaculture in Europe. In a first experiment, feeding rate (FR), growth, absorption efficiency (AE) and survival of adults (135.01 +/- 10.87g eviscerated weight) were assessed under sediment tank conditions. In a second experiment, the feasibility to use sea bream (Sparus aurata) biodeposits as a food source was studied for adults (168.69 +/- 14.59g eviscerated weight). Individuals in the first experiment showed an increase of weight (specific growth rate (SGR)=0.2% d(-1)), positive FRs and mean value of AE close to 80% with a mean organic matter content of 90.07 +/- 11.5mg/g in the offered sediment. Sea cucumbers fed with fish biodeposits showed a reduction of weight (SGR<-0.14%d(-1)), low FRs and negative values of AE. The influence of low salinity and temperature during experiments should be considered to explain these results. Indeed, sea cucumbers can be affected by a decrease of these parameters during winter months resulting in a period of inactivity.
Regional Genetic Structure in the Aquatic Macrophyte Ruppia cirrhosa Suggests Dispersal by Waterbirds
Publication . MARTINEZ, JOHN J.; Bermejo, R.; A, Serrão; Sanchez-Lizaso, J.; Gonzalez-Wanguemert, Mercedes
The evolutionary history of the genus Ruppia has been shaped by hybridization, polyploidisation and vicariance that have resulted in a problematic taxonomy. Recent studies provided insight into species circumscription, organelle takeover by hybridization, and revealed the importance of verifying species identification to avoid distorting effects of mixing different species, when estimating population connectivity. In the present study, we use microsatellite markers to determine population diversity and connectivity patterns in Ruppia cirrhosa including two spatial scales: (1) from the Atlantic Iberian coastline in Portugal to the Siculo-Tunisian Strait in Sicily and (2) within the Iberian Peninsula comprising the Atlantic-Mediterranean transition. The higher diversity in the Mediterranean Sea suggests that populations have had longer persistence there, suggesting a possible origin and/or refugial area for the species. The high genotypic diversities highlight the importance of sexual reproduction for survival and maintenance of populations. Results revealed a regional population structure matching a continent-island model, with strong genetic isolation and low gene flow between populations. This population structure could be maintained by waterbirds, acting as occasional dispersal vectors. This information elucidates ecological strategies of brackish plant species in coastal lagoons, suggesting mechanisms used by this species to colonize new isolated habitats and dominate brackish aquatic macrophyte systems, yet maintaining strong genetic structure suggestive of very low dispersal.
First report of the nutritional profile and antioxidant potential of Holothuria arguinensis, a new resource for aquaculture in Europe
Publication . Roggatz, Christina C.; Gonzalez-Wanguemert, Mercedes; Pereira, Hugo; Rodrigues, Maria Joao; F. G. M. Silva, Manuela; Barreira, Luísa; Varela, João; Custódio, Luísa
This work reports for the first time the nutritional profile and antioxidant potential of the edible sea cucumber Holothuria arguinensis from the North-eastern Atlantic. H. arguinensis has high levels of protein, with the amino acids profile dominated by alanine, glycine and proline and low lysine/arginine ratios. Its carbohydrate and energetic contents are also low as well as the total lipid levels, although its lipid profile is rich in polyunsaturated fatty acids (PUFA), especially arachidonic, eicosapentaenoic and docosahexaenoic acids. In addition, H. arguinensis has high levels of calcium. The water and ethanol extracts show ability to scavenge free radicals and to chelate copper and iron ions. Our results indicate that H. arguinensis has a balanced nutritional quality suitable for human consumption. In addition, it contains compounds with antioxidant potential; thus its intake can contribute for a healthy and well-balanced diet.
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Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
3599-PPCDT
Funding Award Number
PTDC/MAR/119363/2010