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- Ontogenia do sistema imunitário de corvina (Argyrosomus regius) a diferentes temperaturasPublication . Pires, Damiana Marques; Baptista, Teresa Maria Coelho; Soares, Florbela Maria BenjamimArgyrosomus regius é uma espécie emergente em aquacultura com conhecimento limitado do tempo de aparecimento e desenvolvimento de seu sistema imunológico durante o desenvolvimento ontogénico, o que é importante para prevenir surtos de doenças. Assim, o primeiro passo é determinar o aparecimento dos órgãos linfáticos, de modo a que possam ser aplicadas medidas profiláticas, para que os indivíduos adquiram resistência ao invés de tolerância. Este estudo avaliou o aparecimento de órgãos linfáticos em larvas de corvina cultivadas a duas temperaturas diferentes (15 ± 0,7 e 18 ± 0,5°C). As larvas foram obtidas a partir de reprodutores F1, mantidos na estação de Piloto de Piscicultura de Olhão (EPPO) pertencente ao IPMA (Instituto Português do Mar e Atmosfera). O cultivo larvar foi realizado em tanques cilíndrocónicos, em duplicados, com densidade inicial de 26 larvas L-1. O fotoperíodo foi de 14h-10h dia-noite e a renovação da água começou em 15%.h-1, aumentando para 40%.h-1 em sistema aberto. Também foi aplicado o método da água verde adicionando uma mistura de duas microalgas Nannochloropsis oculata (No) e Isochrysis galbana (Tiso). Dos 3 dias após a eclosão (DAE) até 10 DAE, as larvas foram alimentadas com rotíferos (Brachionus spp.). A artemia sp. foi fornecida desde 8 DAE e a alimentação inerte foi introduzida a 9 DAE. Ambos, rotíferos e Artémia, foram enriquecidos com RedPepper ® (Bernaqua TM) antes de serem fornecidos às larvas. A amostragem larvar foi realizada diariamente para biometria (comprimento total (mm) e peso seco (mg)) e histologia. Aos 20 DAE as larvas apresentaram maior comprimento total e peso seco (6,67±0,56mm; 0,56±0,06mg) no tratamento a 18°C em comparação com as larvas do tratamento a 15°C (4,77±0,38 mm; 0,12±0,04mg). Em relação ao aparecimento dos órgãos linfáticos, a sequência do seu aparecimento foi a seguinte: rim anterior (0 DAE), baço (6 DAE) e timo (8 DAE) para ambas as temperaturas. Assim, conclui-se que a temperatura não influenciou o aparecimento dos órgãos linfáticos, no entanto afetou o crescimento das larvas.
- Effect on health status and pathogen resistance of gilthead seabream (Sparus aurata) fed with diets supplemented with Gracilaria gracilisPublication . Passos, Ricardo; Correia, Ana Patrícia; Ferreira, Inês; Pires, Pedro; Pires, Damiana; Gomes, Emma; Carmo, Beatriz do; Santos, Paulo; Simões, Marco; Afonso, Clélia; Baptista, TeresaAquaculture intensification turns the reared populations prone to disease outbreaks, leading the industry to use antibiotics and chemotherapeutics. As the industry is searching for solutions, the development of sustainable aquafeeds with immunostimulant properties is emerging. This work aimed to assess the health benefits of Gracilaria gracilis as a supplement in Sparus aurata feed as well as its protective effect in a bacterial challenge. G. gracilis supplementation improved growth performance and influenced the haematological profile, namely in the constitution of the leukocytic population and erythrocytes size. Algae powder supplementation did not compromise the hepatic antioxidant systems and intestinal health and morphology were not affected by the algal supplementations. Algal extract improved lysozyme plasmatic concentration and a 5% algae powder inclusion was able to successfully protect the fish against a Photobacterium damselae subsp. piscicida infection, granting a 95% survival. In general, a 5% G. gracilis powder diet supplementation was able to improve growth, health, and bacterial resistance in gilthead seabream.
- Potential use of macroalgae Gracilaria gracilis in diets for European seabass (Dicentrarchus labrax): Health benefits from a sustainable sourcePublication . Passos, Ricardo; Correia, Ana Patrícia; Pires, Damiana; Pires, Pedro; Ferreira, Inês; Simões, Marco; Carmo, Beatriz do; Santos, Paulo; Pombo, Ana; Afonso, Clélia; Baptista, TeresaSeaweeds still possess a large undisclosed potential, mainly due to their constituent’s richness, which may have several uses for society. In aquaculture, they may play a role as an ecological sustainable aquafeed supplement to increase overall health and fight pathogenic outbreaks. This study aimed to evaluate the general health modulation that the inclusion of Gracilaria gracilis could accomplish in the diet of Dicentrarchus labrax. Dried algae at 2.5% and 5% and algal extract at 0.35% inclusion levels were supplemented to seabass diet to evaluate possible growth, haematological, immunological, antioxidant, metabolic, and intestinal morphological modulations. The supplementations did not impact growth or feed utilization, and barely affected the haematological profile and some metabolic parameters. Nevertheless, it caused a marked outcome on lysozyme, some oxidative stress biomarkers, and intestine morphology, suggesting beneficial consequences from the algal inclusion. Dried algae powder, with a 2.5% inclusion, boosted immune response, with higher plasmatic lysozyme and intestinal acid goblet cells and protected against oxidative damages by improved enzymatic and non-enzymatic responses. Thus, we provide evidence that dietary seaweed application may be a path towards a more sustainable aquaculture industry.
- Lidocaine supplementation in clove-oil and 2-phenoxyethanol anesthesia for gilthead seabream (Sparus aurata)Publication . Tchobanov, Carolina F.; Vaz, Mariana; Pires, Damiana; Passos, Ricardo; Antunes, Luís M.; Baptista, TeresaAnimal welfare and reducing stress during procedures are key objectives for success in animal production. Anesthesia has been used for procedures to reduce animal stress and its negative impact on welfare. This study aimed first to refine the concentrations of the anesthetic clove-oil (CO) and lidocaine (L) in gilthead seabream (Sparus aurata) juveniles (56.0 ± 15.09 g) and then combine clove-oil and 2-phenoxyethanol (2PHE) with the refined concentration of lidocaine. The concentrations of clove-oil (30, 45, and 60 mg L− 1), and the concentrations of lidocaine (2.5, 5, and 7.5 mg L− 1), were evaluated in the refinement trial. Based on these results, a second trial was performed with 45 mg L− 1 CO or 0.4 mL L− 1 2PHE as anesthetics alone or combined with 2.5 mg L− 1 of lidocaine. Results from this work showed an improvement in induction times for 2-phenoxyethanol when lidocaine was added (2PHE 179.53 ± 63.21 s; 2PHE + L 130.65 ± 40.16 s). Recovery time also showed a reduction for clove-oil when lidocaine was used (CO 349.90 ± 123.69 s; CO + L 250.11 ± 51.99 s). The use of lidocaine showed better results, reducing lactate and histological progressive alterations. Lidocaine showed stress-induced oxidative alterations when it was combined with 2-phenoxyethanol. Lidocaine exposure increased ALT, AST, histological regressive alterations for both anesthetics, and gene expression of hsp70 in the gills when clove-oil was used. Further studies are necessary to comprehend the synergistic effects of lidocaine when combined with synthetic and natural anesthetics and to discern potential acute or chronic toxic responses in fish. These insights will be crucial for refining anesthesia protocols and ensuring the well-being of aquatic species in aquaculture practices and research settings.
- Early immune modulation in European Seabass (Dicentrarchus labra) juveniles in response to Betanodavirus infectionPublication . Vaz, Mariana; Pires, Damiana; Pires, Pedro; Simões, Marco; Pombo, Ana; Santos, Paulo; Carmo, Beatriz do; Passos, Ricardo; Costa, Janina Z.; Thompson, Kim D.; Baptista, TeresaThe early host–pathogen interaction between European seabass (Dicentrarchus labrax) and Betanodavirus was examined by using juvenile fish infected intramuscularly with RGNNV (red-spotted grouper nervous necrosis virus). The time course selected for sampling (0–144 h post-infection (hpi)) covered the early stages of infection, with hematological, antioxidant and immunological responses examined. Early activation of the host’s immune system was seen in the first few hours post-infection (6 to 9 hpi), as evidenced by an increase in tnfa, cd28 and c3 expression in the head kidney of infected fish. Most hematological parameters that were examined showed significant differences between sampling times, including differences in the number of thrombocytes and various leukocyte populations. The plasma lysozyme concentration decreased significantly over the course of the trial, and most antioxidant parameters examined in the liver showed significant differences over the infection period. At 144 hpi, peak expression of tnfa and il-1b coincided with the appearance of disease symptoms, peak levels of virus in the brain and high levels of fish mortality. The results of the study show the importance of analyzing the early interactions between European seabass and Betanodavirus to establish early indicators of infection to prevent more severe outcomes of the infection from occurring.
- Principais Patógenos que Afetam Peixes Cultivados em PortugalPublication . Pires, Damiana; Vaz, Mariana; Pires, Pedro; Passos, Ricardo; Carmo, Beatriz; Santos, Paulo; Tomás, Mafalda; Ferreira, Susana M. F.; Baptista, TeresaA mortalidade de peixes que ocorre nas explorações aquícolas, devida à ação de agentes patogénicos, constitui ainda um dos maiores entraves ao desenvolvimento económico do sector. Tendo em conta a sua origem, as doenças podem subdividir-se em não infeciosas e infeciosas, sendo estas últimas as de maior importância e a principal causa de perdas económicas elevadas. As doenças infeciosas agrupam-se em três categorias, de acordo com a sua etiologia viral, bacteriana e parasítica. Estas doenças são muitas vezes indicadoras de condições fisiológicas e patológicas, resultantes de alimentação inadequada, infeções subclínicas, ou condições ambientais adversas. Quando simultaneamente existem condições favoráveis para a multiplicação do patógeno e condições adversas para os peixes, observa-se o desenvolvimento da doença. Entre as condições adversas que podem diminuir a resposta imune dos peixes cultivados, provocando uma maior predisposição aos patógenos, enumeram-se: densidade elevada, baixos níveis de oxigénio, stress alimentar, stress provocado pelo transporte, acumulação de compostos azotados, alterações de pH, entre outros. Estas situações, tendo em conta as consequências, merecem uma atenção redobrada por parte dos aquicultores.
- Proximate composition and fatty acid profile of Gilthead seabream (Sparus aurata) fed with Pelvetia canaliculata supplemented diets: An insight towards the valorization of seaweed biomassPublication . Antunes, Madalena; Neves, Marta; Pires, Damiana; Passos, Ricardo; Carmo, Beatriz do; Tchobanov, Carolina F.; Forte, Sara; Vaz, Mariana; Baptista, Teresa; Tecelão, CarlaSeaweeds are a sustainable source of protein and lipids that may be used to replace fish by-products in aquaculture feed. This study aimed at using the macroalgae Pelvetia canaliculata as an ingredient in gilthead seabream (Sparus aurata) feed, either as freeze-dried powder or as algae residue (waste) that was obtained after the supplementation of sunflower oil. The formulated diets and the fish muscle were analyzed concerning the proximate composition and the fatty acid profile. The health lipid indices hypocholesterolemic/ hypercholesterolemic (h/H), atherogenic (AI), thrombogenic (TI), as well as n-3/n-6 and polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) ratios were calculated. Additionally, the peroxidizability index (PI) was determined. No differences were observed in the proximate composition of fish muscle regardless of the diet used. Fish fed a diet supplemented with 10% of algae waste (W10) stand out for the highest content in oleic acid (C18:1 n-9), and the lowest in both linoleic (C18:2 n-6) and palmitic (C16:0) fatty acids. All fish samples showed values of health lipid indices within the limits recommend for a nutritional balanced diet. These results highlight that fish fed diets supplemented with P. canaliculata are sources of healthy lipids that might be consumed on a regular basis to prevent cardiovascular diseases.
- Pelvetia canaliculata as an aquafeed supplement for gilthead seabream Sparus aurata: A biorefinery approach for seaweed biomass valorisationPublication . Pires, Damiana; Passos, Ricardo; Carmo, Beatriz do; Tchobanov, Carolina F.; Forte, Sara; Vaz, Mariana; Antunes, Madalena; Tecelão, Carla; Baptista, TeresaFor sustainable and economically viable aquaculture, it is necessary to search for alternative sources of aquafeeds. Algae have been studied because of their bioactive compounds with several activities such as antioxidants. The direct incorporation of the macroalgae Pelvetia canaliculata in sunflower oil to increase oxidative stability and biological value results in waste with high nutritional value that may be used as an ingredient in aquaculture feed. This study aimed to evaluate the effect of incorporating algae powder (PEL 1%, PEL 10%) and algae waste obtained after sunflower oil supplementation (WO 1%, WO 10%) in aquafeeds for gilthead seabream. We studied the growth performance, haematological profile, oxidative stress and metabolic parameters, and intestine histomorphology. Experimental diets did not influence growth performance or somatic indexes, and barely affected the haematological profile. Catalase showed higher activity in seabream fed with PEL10 than with control diet. Total glutathione had a higher activity in fish fed with both WO diets. Plasmatic levels of cholesterol were higher in PEL1 and WO10. Triglyceride levels were higher in WO1 and total lipids were higher in both WO diets. The histomorphology of the intestine was slightly modulated by experimental diets but was not affected negatively. In general, supplementation with Pelvetia powder and algal waste oil may be used as an aquafeed for gilthead seabream according to the results obtained for growth, some haematological parameters, catalase and total glutathione, intestinal villi length, and the number of total and acid goblet cells.