Percorrer por autor "Costas, Benjamín"
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- Alternative proteins for fish diets: implications beyond growthPublication . Aragão, Cláudia; Gonçalves, Ana Teresa; Costas, Benjamín; Azeredo, Rita; Xavier, Maria João; Engrola, SofiaAquaculture has been challenged to find alternative ingredients to develop innovative feed formulations that foster a sustainable future growth. Given the most recent trends in fish feed formulation on the use of alternative protein sources to decrease the dependency of fishmeal, it is fundamental to evaluate the implications of this new paradigm for fish health and welfare. This work intends to comprehensively review the impacts of alternative and novel dietary protein sources on fish gut microbiota and health, stress and immune responses, disease resistance, and antioxidant capacity. The research results indicate that alternative protein sources, such as terrestrial plant proteins, rendered animal by-products, insect meals, micro- and macroalgae, and single cell proteins (e.g., yeasts), may negatively impact gut microbiota and health, thus affecting immune and stress responses. Nevertheless, some of the novel protein sources, such as insects and algae meals, have functional properties and may exert an immunostimulatory activity. Further research on the effects of novel protein sources, beyond growth, is clearly needed. The information gathered here is of utmost importance, in order to develop innovative diets that guarantee the production of healthy fish with high quality standards and optimised welfare conditions, thus contributing to a sustainable growth of the aquaculture industry.
- Amino acid supplementation in fish nutrition and welfarePublication . Aragão, Cláudia; Engrola, Sofia; Costas, BenjamínAmino acids are not only the fundamental building blocks of proteins and, consequently, essential for animal growth, but they have also gained recognition in recent years for their critical roles in regulating key metabolic processes. In aquaculture, where the demand for more sustainable production systems continues to grow, nutrition remains a central pillar. Within this context, amino acids serve dual purposes: they are essential to balance the nutritional profiles of alternative protein sources, and they also act as functional ingredients that can enhance fish health, robustness, and resilience to stressors.
- Amyloodiniosis in aquaculture: A reviewPublication . Moreira, Márcio; Costas, Benjamín; Rodrigues, Pedro; Lourenço‐Marques, Cátia; Sousa, Rui; Schrama, Denise; Raposo de Magalhães, Cláudia; Farinha, Ana Paula; Soares, FlorbelaFish ectoparasites are one of the pathogens groups that pose great concern to the aquaculture industry. The dinoflagellate Amyloodinium ocellatum is responsible for amyloodiniosis, a parasitological disease with a strong economic impact in temperate and warm water aquaculture, mainly in earthen pond semi-intensive systems. Amyloodiniosis represents one of the most important bottlenecks for aquaculture and, with the predictable expansion of the area of influence of this parasite to higher latitudes due to global warming it might also be a threat to other aquaculture species that are not yet parasitized by A. ocellatum. This review made a compilation of the existing knowledge about this parasite and the disease associated with it. It was noticed that, except from the life cycle characterisation, detection methods, histopathological analysis, and treatments, there are still a lot of areas that need a further investment in research. Areas like parasite-host interactions, epidemiological models, taxonomy, host physiological responses to parasitism, and genome sequencing, amongst others, can contribute to a better understanding of this disease. These proposed approaches and routes of investigation will enhance and contribute to a more standardised knowledge, creating the opportunity for a better understanding of amyloodiniosis impacts on fish and contributing for the development of new tools against A. ocellatum, that may reduce fish mortality in aquaculture production due to amyloodiniosis outbreaks.
- Cutting-Edge methods in Teleost and Chondrichthyan reproductive biologyPublication . Mechaly, Alejandro S.; Awruch, Cynthia; Cabrita, Elsa; Costas, Benjamín; Fernandes, Jorge M.O.; Gallego, Victor; Hirt-Chabbert, Jorge; Konstantinidis, Ioannis ; Oliveira, Catarina; Ramos Júdez, Sandra; Ramos-Pinto, Lourenço ; Fatsini Fernández, ElviraReproduction is a fundamental biological process for producing offspring and ensuring the continuation of the species. With nearly 35,000 fish species worldwide exhibiting a very diverse range of reproductive systems and strategies, the study of fish reproduction is a significant challenge. Research into various fish reproductive models is driven by their use in human biomedical applications, improving the diversification and sustainability of aquaculture species, and developing strategies for biodiversity conservation. These models must be approached from an animal ethics perspective, considering the welfare of the species under study and applying the 3Rs principle (Replacement, Reduction and Refinement). This principle focusses on replacing animals with alternative methods wherever possible, reducing the number of animals used and refining procedures to minimize suffering. While destructive sampling of wild aquatic species should be minimized, the need remains to provide information on reproduction as an important parameter for delineating management and conservation programs. One of the practices that helps reduce and replace the use of animal testing is the scientific study of individuals obtained through bycatch. This is the case for some chondrichthyans, and endangered fish species included in conservation programs. Regarding fish species that are kept under human care (commonly called captivity), studies on reproduction are essential to improve well-being and increase production of farmed species. Research on fish reproduction requires expanding basic knowledge of broodstock management tools, such as gamete quality assessment, reproductive behavior studies, the use of hormone therapies to stimulate reproduction, and the development of non-lethal or less invasive methods using body fluids (e.g., mucus, seminal plasma, blood plasma, or urine) to study reproductive status, as well as novel markers from state-of-the-art omics research. This review describes a multidisciplinary approach that includes the aforementioned reproductive management tools, indicators of welfare, and next-generation sequencing techniques using samples collected by minimally invasive methods.
- Dietary tryptophan intervention counteracts stress-induced transcriptional changes in a teleost fish HPI axis during inflammationPublication . Peixoto, Diogo; Carvalho, Inês; Machado, Marina; Aragão, Cláudia; Costas, Benjamín; Azeredo, RitaImmune nutrition is currently used to enhance fish health by incorporating functional ingredients into aquafeeds. This study aimed to investigate the connections between tryptophan nutrition and the network that regulates the communication pathways between neuroendocrine and immune systems in European seabass (Dicentrarchus labrax). When tryptophan was supplemented in the diet of unstressed fish, it induced changes in the hypothalamic-pituitary-interrenal axis response to stress. Tryptophan-mediated effects were observed in the expression of anti-inflammatory cytokines and glucocorticoid receptors. Tryptophan supplementation decreased pro-opiomelanocortin b-like levels, that are related with adrenocorticotropic hormone and cortisol secretion. When stressed fish fed a tryptophan-supplemented diet were subjected to an inflammatory stimulus, plasma cortisol levels decreased and the expression of genes involved in the neuroendocrine response was altered. Modulatory effects of tryptophan dietary intervention on molecular patterns seem to be mediated by altered patterns in serotonergic activity.
- Dietary tryptophan intervention counteracts stress-induced transcriptional changes in a teleost fish HPI axis during inflammationPublication . Peixoto, Diogo; Carvalho, Inês; Machado, Marina; Aragão, Cláudia; Costas, Benjamín; Azeredo, RitaImmune nutrition is currently used to enhance fish health by incorporating functional ingredients into aquafeeds. This study aimed to investigate the connections between tryptophan nutrition and the network that regulates the communication pathways between neuroendocrine and immune systems in European seabass (Dicentrarchus labrax). When tryptophan was supplemented in the diet of unstressed fish, it induced changes in the hypothalamic-pituitary-interrenal axis response to stress. Tryptophan-mediated effects were observed in the expression of anti-inflammatory cytokines and glucocorticoid receptors. Tryptophan supplementation decreased pro-opiomelanocortin b-like levels, that are related with adrenocorticotropic hormone and cortisol secretion. When stressed fish fed a tryptophan-supplemented diet were subjected to an inflammatory stimulus, plasma cortisol levels decreased and the expression of genes involved in the neuroendocrine response was altered. Modulatory effects of tryptophan dietary intervention on molecular patterns seem to be mediated by altered patterns in serotonergic activity.
- Dietary tryptophan plays a role as an anti-inflammatory agent in european seabass (dicentrarchus labrax) juveniles during Chronic InflammationPublication . Azeredo, Rita; Peixoto, Diogo; Paulo Santos; Duarte, Inês; Ricardo, Ana; Machado, Marina; Costas, Benjamín; Aragão, CláudiaWhere teleost fish are concerned, the effects of a dietary tryptophan surplus are mostly immunosuppressive, making it a potential dietary anti-inflammatory strategy. The goal of the present work was to evaluate the effects of tryptophan dietary supplementation on immune and neuroendocrine responses of the European seabass, Dicentrarchus labrax, undergoing chronic inflammation. Juvenile European seabass were intraperitoneally injected with an inflammatory agent (inflamed group) or a saline solution (control group). Within each group, fish were fed a control and a control-based diet supplemented with tryptophan for 4 weeks. Different tissues were sampled every week for the assessment of immune-related parameters. When tryptophan was provided to fish undergoing inflammation, the gene expression of a macrophage marker increased sooner and remained high until the end of the experiment. The same fish showed a concurrent increase in peripheral monocyte counts. After one week, molecular patterns of anti-inflammatory processes seemed to be favoured by tryptophan. Altogether, results show that a short administration period seems to be critical where tryptophan supplementation is concerned since at later inflammatory stages—and longer feeding periods—fish fed this diet displayed a molecular profile similar to that of fish fed a control diet.
- Immune status and hepatic antioxidant capacity of Gilthead Seabream Sparus aurata juveniles fed yeast and microalga derived β-glucansPublication . Reis, Bruno; Gonçalves, Ana Teresa; Santos, Paulo; Sardinha, Manuel; Conceição, Luís E. C.; Serradeiro, Renata; Pérez-Sánchez, Jaume; Calduch-Giner, Josep; Schmid-Staiger, Ulrike; Frick, Konstantin; Dias, Jorge; Costas, BenjamínThis work aimed to evaluate the effects of dietary supplementation with β-glucans extracted from yeast (Saccharomyces cerevisiae) and microalga (Phaeodactylum tricornutum) on gene expression, oxidative stress biomarkers and plasma immune parameters in gilthead seabream (Sparus aurata) juveniles. A practical commercial diet was used as the control (CTRL), and three others based on CTRL were further supplemented with different β-glucan extracts. One was derived from S. cerevisiae (diet MG) and two different extracts of 21% and 37% P. tricornutum-derived β-glucans (defined as Phaeo21 and Phaeo37), to give a final 0.06% β-glucan dietary concentration. Quadruplicate groups of 95 gilthead seabream (initial body weight: 4.1 ± 0.1 g) were fed to satiation three times a day for 8 weeks in a pulse-feeding regimen, with experimental diets intercalated with the CTRL dietary treatment every 2 weeks. After 8 weeks of feeding, all groups showed equal growth performance and no changes were found in plasma innate immune status. Nonetheless, fish groups fed β-glucans supplemented diets showed an improved anti-oxidant status compared to those fed CTRL at both sampling points (i.e., 2 and 8 weeks). The intestinal gene expression analysis highlighted the immunomodulatory role of Phaeo37 diet after 8 weeks, inducing an immune tolerance effect in gilthead seabream intestine, and a general down-regulation of immune-related gene expression. In conclusion, the results suggest that the dietary pulse administration of a P. tricornutum 37% enriched-β-glucans extract might be used as a counter-measure in a context of gut inflammation, due to its immune-tolerant and anti-oxidative effects.
- New developments and biological insights into the farming of Solea senegalensis reinforcing its aquaculture potentialPublication . Morais, Sofia; Aragão, C.; Cabrita, Elsa; Conceição, L. E. C.; Constenla, Maria; Costas, Benjamín; Dias, Jorge; Duncan, Neil; Engrola, S.; Estevez, Alicia; Gisbert, Enric; Mañanós, Evaristo; Valente, Luísa M. P.; Yúfera, M.; Dinis, Maria TeresaSenegalese sole was one of the earliest identified candidate species with high potential for aquaculture diversification in the south of Europe. Its culture has been possible, and commercially attempted, for several decades, but intensive production has been slow to take off. This has been explained mostly by serious disease problems, high mortality at weaning, variable growth and poor juvenile quality. However, a strong and sustained research investment that started in the eighties has led to a better understanding of the requirements and particularities of this species. More recently, better management and technical improvements have been introduced, which have led to important progress in productivity and given a new impetus to the cultivation of Senegalese sole. As a result, the last 5 years have marked a probable turning point in the culture of sole towards the development of a knowledge-driven, competitive and sustainable industry. This review will focus on the main technical improvements and advances in the state of knowledge that have been made in the last decade in areas as diverse as reproductive biology, behaviour, physiology, nutritional requirements, modulation of the immune system in response to environmental parameters and stress, and characterization and mitigation of the main disease threats. It is now clear that Senegalese sole has important particularities that differentiate it from other current and candidate marine aquaculture species, which bring about important challenges, some still unsolved, but also notable opportunities (e.g. a nutritional physiology that is better adapted to dietary vegetable ingredients), as will be discussed here.
- Tryptophan modulatory role in European Seabass (Dicentrarchus labrax) immune response to acute inflammation under stressful conditionsPublication . Machado, Marina; Peixoto, Diogo; Santos, Paulo; Ricardo, Ana; Duarte, Inês; Carvalho, Inês; Raquel Cêa de Aragão Teixeira, Cláudia; Azeredo, Rita; Costas, BenjamínThe present work aimed to study the role of dietary tryptophan supplementation in modulating the European seabass (Dicentrarchus labrax) immune condition during stressful rearing conditions (i.e., 15 days exposure to high density), as well as the immune response to acute inflammation after intraperitoneal injection of a bacterial pathogen. Stress alone did not compromise seabass health indicators. In contrast, a clear peripheral and local inflammatory response was observed in response to the inoculated bacteria. Moreover, exposure to a high stocking density seemed to exacerbate the inflammatory response at early sampling points, compared to fish stocked at a lower density. In contrast, stressed fish presented some immune-suppressing effects on the T-cell surface glycoprotein receptor expressions at a late sampling point following inflammation. Regarding the effects of dietary tryptophan, no changes were observed on seabass immune indicators prior to inflammation, while a small number of immunosuppressive effects were observed in response to inflammation, supporting tryptophan’s role in the promotion of immune-tolerance signals during inflammation. Nonetheless, tryptophan dietary supplementation improved the inflammatory response against a bacterial pathogen during stressful conditions, supported by a reduction of plasma cortisol levels, an up-regulation of several immune-related genes at 48 h, and an inversion of the previously observed, stress-induced T-cell suppression. Finally, the involvement of tryptophan catabolism in macrophages was confirmed by the up-regulation of genes involved in the kynurenine pathway. The present study brings new insights regarding the immune modulatory role of tryptophan during stressful conditions in fish, thus allowing for the development of novel prophylactic protocols during vaccination by intraperitoneal injection in the European seabass.