Browsing by Author "Soares, F."
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- Antemortem versus postmortem methods for detection of betanodavirus in Senegalese sole (Solea senegalensis)Publication . Olveira, J. G.; Soares, F.; Engrola, Sofia; Dopazo, C. P.; Bandín, I.The suitability of nested reverse transcription polymerase chain reaction (nRT-PCR) to detect betanodavirus in blood samples from naturally infected Senegalese sole (Solea senegalensis) was evaluated in comparison with other diagnostic methods. Results indicated that histologic examination of brain lesions could be regarded as the most consistent indicator of nodavirus infection in this species. The nRT-PCR showed low to moderate levels of detection; the best values were obtained in brain samples followed by blood samples. Inoculation of SSN-1 and SAF-1 cells with fish samples did not cause cytopathic effect, although virus was detected by reverse transcription polymerase chain reaction in approximately 25% of the SSN-1 inoculated wells. The efficiency of detection of the viral genome was dramatically increased by the use of nRTPCR, reaching 90.6% of positives in brain samples and 84.4% in blood samples. The sensitivity and the negative predictive value of nRT-PCR in blood samples were slightly lower than those obtained using brain samples. Nevertheless, it is suggested that the advantage of being able to perform diagnosis on live fish adequately counterbalances the slightly lower sensitivity of nRT-PCR on blood samples. This technique is proposed as a useful tool, not only for the selection of nodavirus-free breeders but also to check the fish status during ongrowing.
- Effect of amino acid supplementation and stress on expression of molecular markers in meagre (Argyrosomus regius)Publication . Herrera, M.; Matias, A. C.; Soares, F.; Ribeiro, L.; Moreira, Márcio; Salamanca, N.; Jerez-Cepa, I.; Mancera, J. M.; Astola, A.The objectives of this work were: 1) develop of molecular stress biomarkers obtaining sequence data of different transcripts, 2) study the molecular stress response through the expression quantification of key gene involved in it, and 3) assess the effects of dietary amino acid additives on stress response in meagre meagres (Argyrososmus regius). Fish batches were fed two experimental diets with tryptophan (Trp) or aspartate (Asp) added for seven days. Before sampling fish were submitted to confinement/netting stress during 1 h, except control fish. Therefore fish were sampled before and after stress (1 h and 6 h post-stress). The sampling consisted of blood and tissues (brain, hypophysis and liver). Several gene expressions related to the stress response were measured in those tissues, and the cloning of corticotropin-releasing hormone (crh), corticotropin-releasing hormone binding protein (crh-bp), and thyrotropin-releasing hormone (trh) has been reported in meagre for the first time. In fact, fish fed an additional Asp diet did not present any sl, prl and gh expression changes, as for the control group. Contrarily, the Trp diet altered the prl and gh expressions after stress. For crh and crh-bp expressions, no significant differences were detected within the Asp diet hence that amino acid improved the stress response. However, Asp feeding, but not Trp, enhanced pomc-a expression after stress. Hsp70 expression varied for every treatment, including the control feeding, indicating a late response at 6 h post-stress sampling, where both Asp and Trp treatments increased these expressions significantly. Concluding, the response of molecular stress markers to amino acid enriched diets was diverse. The stressor did not change significantly the relative expression of most analyzed genes for control feeding groups, though the Asp supplemented diet was more effective for attenuating molecular markers than the Trp one.
- Methodology for assessing the individual role of fish, oyster, phytoplankton and macroalgae in the ecology of integrated production in earthen pondsPublication . Cunha, M.E.; Quental-Ferreira, H.; Parejo, A.; Gamito, Sofia; Ribeiro, L.; Moreira, M.; Monteiro, I.; Soares, F.; Pousão-Ferreira, PedroProduction costs in extensive and semi-intensive fish culture in earthen ponds are often too high to offer sustainable economic activity due to the low productivity of these systems. The right combination of commercial finfish species with inorganic (primary producers) and organic extractive (bivalves) species in Integrated MultiTrophic Aquaculture (IMTA) create a balanced system with higher profitability and risk reduction. To achieve this, it is crucial to understand the role of each functional groups within the system what we did by comparing three different IMTA production three different IMTA production treatments with distinct combinations of trophic levels: •fish, filter feeders, phytoplankton and macroalgae,•fish, filter feeders and phytoplankton•fish, phytoplankton and macroalgae Each treatment was carried out in two similar ponds under semi-intensive conditions and flow through system, in a total of 6 earthen ponds of 500 m2 surface and depth of 1.5 m. Results showed that the presence of oysters in the ponds enhanced water quality by decreasing turbidity and by controlling phytoplankton which led to regulation of dissolved oxygen levels. The enhanced water quality in these systems lead to improved fish performance and higher biomass production contributing to greater profitability. The combination of fish, oyster, phytoplankton and macroalgae was particularly good providing much more fish supply compared with the other two treatments. •Oysters enhanced water quality in the ponds by decreasing turbidity and controlling phytoplankton which regulated the dissolved oxygen levels.•The enhanced water quality in systems with oysters improve fish performance resulting in higher biomass production and greater profitability.•The combination of fish, oyster, phytoplankton and macroalgae was particularly good providing much more fish supply compared with the other two treatments.
- Physiological responses of reared sea bream (Sparus aurata Linnaeus, 1758) to an Amyloodinium ocellatum outbreakPublication . Moreira, M.; Schrama, Denise; Soares, F.; Wulff, T.; Pousao-Ferreira, P.; Rodrigues, PedroAmyloodiniosis represents a major bottleneck for semi-intensive aquaculture production in Southern Europe, causing extremely high mortalities. Amyloodinium ocellatum is a parasitic dinoflagellate that can infest almost all fish, crustacean and bivalves that live within its ecological range. Fish mortalities are usually attributed to anoxia, associated with serious gill hyperplasia, inflammation, haemorrhage and necrosis in heavy infestations; or with osmoregulatory impairment and secondary microbial infections due to severe epithelial damage in mild infestation. However, physiological information about the host responses to A.ocellatum infestation is scarce. In this work, we analysed the proteome of gilthead sea bream (Sparus aurata) plasma and relate it with haematological and immunological indicators, in order to enlighten the different physiological responses when exposed to an A.ocellatum outbreak. Using 2D-DIGE, immunological and haematological analysis and in response to the A.ocellatum contamination we have identified several proteins associated with acute-phase response, inflammation, lipid transport, homoeostasis, and osmoregulation, wound healing, neoplasia and iron transport. Overall, this preliminary study revealed that amyloodiniosis affects some fish functional pathways as revealed by the changes in the plasma proteome of S. aurata, and that the innate immunological system is not activated in the presence of the parasite.
- The effect of live feeds bathed with the red seaweed Asparagopsis armata on the survival, growth and physiology status of Sparus aurata larvaePublication . Castanho, Sara; Califano, Gianmaria; Soares, F.; Costa, Rodrigo; Mata, L.; Pousao-Ferreira, P.; Ribeiro, L.Larval rearing is affected by a wide range of microorganisms that thrive in larviculture systems. Some seaweed species have metabolites capable of reducing the bacterial load. However, no studies have yet tested whether including seaweed metabolites on larval rearing systems has any effects on the larvae development. This work assessed the development of Sparus aurata larvae fed preys treated with an Asparagopsis armata product. Live prey, Brachionus spp. and Artemia sp., were immersed in a solution containing 0.5% of a commercial extract of A. armata (Ysaline 100, YSA) for 30 min, before being fed to seabream larvae (n = 4 each). In the control, the live feed was immersed in clear water. Larval parameters such as growth, survival, digestive capacity (structural-histology and functional-enzymatic activity), stress level (cortisol content), non-specific immune response (lysozyme activity), anti-bacterial activity (disc-diffusion assay) and microbiota quantification (fish larvae gut and rearing water) were monitored. Fish larvae digestive capacity, stress level and non-specific immune response were not affected by the use of YSA. The number of Vibrionaceae was significantly reduced both in water and larval gut when using YSA. Growth was enhanced for YSA treatment, but higher mortality was also observed, especially until 10 days after hatching (DAH). The mortality peak observed at 8 DAH for both treatments, but higher for YSA, indicates larval higher susceptibility at this development stage, suggesting that lower concentrations of YSA should be used until 10 DAH. The application of YSA after 10 DAH onwards promotes a safer rearing environment.
- Understanding the individual role of fish, oyster, phytoplankton and macroalgae in the ecology of integrated production in earthen pondsPublication . Cunha, M. E.; Quental-Ferreira, H.; Parejo, A.; Gamito, Sofia; Ribeiro, L.; Moreira, Márcio; Monteiro, I; Soares, F.; Pousao-Ferreira, P.In order to demonstrate that IMTA can be profitable and a good alternative to regular semi-intensive fish mariculture production in earthen ponds three different production treatments with distinct combinations of trophic levels were designed: (i) a combination of fish, filter feeders, phytoplankton and macroalgae, (ii) fish, filter feeders and phytoplankton and (iii) fish, phytoplankton and macroalgae, to evaluate the role of each trophic level within an Integrated Multi-Trophic Aquaculture system (IMTA). Each treatment was carried out under semi-intensive conditions with two replicates, in a total of 6 earthen ponds of 500 m(2) surface and depth of 1.5 m. The results showed that fish, oyster, phytoplankton and macroalgae integrated aquaculture is a healthy sustainable production system for mariculture in earthen ponds, providing much more fish supply compared with the other two treatments. Ponds with filter feeders had significantly lower turbidity (Nephelometric Formazin unit (FNU) of 13 in the morning and 17 in the afternoon) when compared to ponds without filter feeders (16 FNU in the morning and 20 FNU in the afternoon) with increased light penetration throughout water column (61 and 55 cm transparency in ponds with filter feeders compared to 51 cm in ponds without filter feeders) and consequently higher photosynthetic activity with significantly higher dissolved oxygen (5.4 mg L in the morning and 6.7 mg L-1 in the afternoon in ponds with filter feeders compared to 5.3 mg L-1 in the morning and 6.4 mg L-1 in the afternoon in ponds without filter feeders) and carbon sequestration (0.50 and 0.53 mg L-1 8 h(-1) in ponds with filter feeders and 0.43 mg L-1 8 h(-1) in ponds without filter feeders). In the fish, filter feeder, phytoplanton and macroalgae IMTA treatment, phytoplankton played a crucial role because they increased DO levels, removed the excess of nutrients from animal excretion, and was used as food by the filter feeders. Almost as important is the presence of filter feeders since they control the density of the microalgae and particulate matter in the ponds contributing to a more constant level of DO and higher transparency of the water column. The increased transparency and pond fertilization by oyster excretion, resulted in higher proliferation of phytoplankton (chlorophyll a concentrations of 16.5 mu gL(-1) and 20.2 mu g L-1 in ponds with filter feeder and 13.3 mu g L-1 in ponds without filter feeder) with benefits not only for filter feeders themselves but also for the macroalgae. At the end there was higher water quality and higher savings (14% day(-1)) in the energy costs for pond aeration. Meagre, white seabream and flathead grey mullet enhance their performance in IMTA systems with the presence of filter feeders with food conversion rates (FCR) of 1.52 when compared with 2.46 in the regular semi-intensive system composed by fish, phytoplankton and macroalgae. Meagre grew significantly more in IMTA systems with controlled macroalgae while white seabream and flathead grey mullet enhance their performance in the presence of macroalgae. The results show that the fish, oyster, phytoplankton and macroalgae integrated production in earthen ponds is an improved system compared to the regular semi-intensive fish production. The enhanced water quality in these systems leads to improved fish performance and higher biomass production, and to reduction in the energy power used, contributing to greater profitability.