Cláudia Aragão | Universidade do Algarve (original) (raw)
Papers by Cláudia Aragão
한국수산과학회 양식분과 학술대회, May 1, 2015
Aquaculture Nutrition
The dietary protein to energy ratio (P/E) has proven to influence protein utilization and/or grow... more The dietary protein to energy ratio (P/E) has proven to influence protein utilization and/or growth in several fish species. This study intended to unravel the bioavailability and metabolic fate of lysine and methionine in gilthead seabream (Sparus aurata) juveniles fed plant diets with different P/E ratios. Seabream juveniles were fed two isonitrogenous diets (45% crude protein) differing in crude lipids (20 and 14%): LowP/E ( P / E ratio = 20.0 mg protein k J − 1 ) and HighP/E ( P / E ratio = 21.4 mg protein k J − 1 ). After three weeks, fish ( 11.6 ± 4.3 g ) were tube-fed the respective diet labelled with 14C-protein (L-amino acid mixture), 14C-lysine, or 14C-methionine. Protein, lysine, and methionine utilization were determined based on the proportion of 14C-amino acid evacuated, retained in the free or protein-bound fraction of liver and muscle, or catabolized. This study revealed that a decrease in P/E ratio resulted in lower amino acid evacuation (p <0.0...
Aquaculture, Oct 1, 2018
The regulatory role of taurocholic acid (TC) and taurolithocholic acid (TLC) in ion transport was... more The regulatory role of taurocholic acid (TC) and taurolithocholic acid (TLC) in ion transport was investigated with the short-circuit current (Isc) technique in the intestine of Senegalese sole (Solea senegalensis). Under voltage clamp conditions, Isc was stable for over 3 h and averaged −15.42 ± 2.75 μA/cm 2 and −65.28 + 7.69 μA/cm 2 in the anterior and posterior intestine, respectively. Only bumetanide (200 μM), a loop diuretic that inhibits Na + /K + /2Cl − co-transporters, inhibited the absorptive Isc, and apical application of NPPB (200 μM), EIPA (200 μM), glibenclamide (200 μM) and DIDS (200 μM) were without effect in the absorptive current. Apical application of TC and TLC induced rapid (< 1 min) increases in the absorptive current in the anterior and the posterior intestine. The responses were dose dependent in the range of physiological levels of TC or TLC previously detected in the intestine of Senegalese sole, 0.4-4 mM, with higher responses in the posterior intestine at the same doses. The response to apical application of TC and TLC was completely abolished by bumetanide (200 μM). In addition, the effect of TC or TLC in preparations with bilateral reduction of chloride (from 146 to 6 mM) in the chamber saline was reduced by 80%. Conclusions of this study indicate that the bile salts TC and TLC alter ionic transport in the intestine of marine fish enhancing the absorptive pathway. These changes revealed by regulation of Isc are characterized by their dose-dependent action, intestinal region dependency, reversibility, chloride dependence and bumetanide sensitivity.
![Research paper thumbnail of Fate of [3H]-Deoxynivalenol in Rainbow Trout (Oncorhynchus mykiss) Juveniles: Tissue Distribution and Excretion](https://attachments.academia-assets.com/112182779/thumbnails/1.jpg)
](Journal of Aquaculture Research & Development, 2018
Deoxynivalenol (DON), a Fusarium mycotoxin, is one of the most prevalent mycotoxins in aquafeeds.... more Deoxynivalenol (DON), a Fusarium mycotoxin, is one of the most prevalent mycotoxins in aquafeeds. The toxicokinetics of DON are rarely studied in aquatic species. The present study used juvenile rainbow trout (Oncorhynchus mykiss) with a mean initial body weight of 7.72 ± 1.42 g in order to evaluate the pharmacokinetic behaviour and the metabolization of radiolabelled DON ([ 3 H]-DON). In a first trial, 30 fish were tube-fed with four pellets containing a total of 125 ± 0.019 ng of [ 3 H]-DON. At different sampling time points after feeding (1 h, 3 h, 6 h, 12 h or 24 h), the tissue distribution of the [ 3 H]-DON was assessed by liquid scintillation counting. In a second trial, five fish were tube-fed four pellets containing a total of 663 ng of unlabelled-DON. Twenty-four hours after feeding, metabolites of DON excreted into the water were analysed by LC-MS/MS. [ 3 H]-DON was detected in fish liver one hour after tube-feeding, indicating a rapid absorption of DON. In the first hour, [ 3 H]-DON achieved its maximum in the gastro-intestinal tract (GIT) (20.56 ± 8.30 ng). However, 6.19 ± 0.83 ng of [ 3 H]-DON was also detected in the water at this sampling time point. The fast excretion of [ 3 H]-DON (above the average gastric emptying time of trout) might be related to its high-water solubility and consequent excretion with the fluid phase of the chyme. The amount of [ 3 H]-DON in the GIT was stable during the first six hours. Such long transit time of DON through the GIT increases the potential for damage and absorption. The period between six and twelve hours seems to be the turning point in terms of DON excretion. Twelve hours after tube-feeding, the trout excreted 50.71 ± 22.17% of the tube-fed DON amount into water, while at the previous sampling time point (six hours) only 11.03 ± 6.09% were detected. These data suggest that an effective method for gastrointestinal DON detoxification in trout requires a period of action lower than six hours. In the present trial, no DON metabolites were detected in water.
Journal of Marine Science and Engineering, 2023
Mussel meal (species Perna perna) was evaluated as a potential feed additive for whiteleg shrimp ... more Mussel meal (species Perna perna) was evaluated as a potential feed additive for whiteleg shrimp (Litopenaeus vannamei) diets to improve growth and cold resistance. Five experimental diets (0, 1, 2, 3 and 4% of mussel meal inclusion) were tested in quadruplicate in whiteleg shrimp, using twenty polyethylene tanks of 400 L. Each tank was stocked with 40 shrimp (3.5 ± 0.5 g), filled with seawater and kept under constant aeration and a temperature of 28.4 ± 0.4 °C. After 8 weeks, the growth and feed efficiency of the shrimp were evaluated, and a thermal shock was administered. The shrimp that were fed with the addition of 3 or 4% mussel meal in their diets showed similar results as the control (0% inclusion), while the addition of 1 or 2% mussel meal in the diet resulted in a significantly higher final weight, weight gain and relative growth rate and a lower feed conversion ratio. Further, no differences were observed in thermal shock resistance and survival among the treatments. In conclusion, mussel meal can be used as a feed additive in whiteleg shrimp diets to improve growth, and quadratic regression models indicate that the best levels of inclusion range from 1.73 to 2.00%
Animals, 2023
Taurine is a sulphur-containing amino acid with important physiological roles and a key compound ... more Taurine is a sulphur-containing amino acid with important physiological roles and a key compound for the synthesis of bile salts, which are essential for the emulsion and absorption of dietary lipids. This study aimed to evaluate the effects of taurine supplementation to low-fishmeal diets on the metabolism of taurine, bile acids, and lipids of Senegalese sole. A fishmeal (FM) and a plant-protein-based (PP0) diet were formulated, and the latter was supplemented with taurine at 0.5 and 1.5% (diets PP0.5 and PP1.5). Diets were assigned to triplicate tanks containing 35 fish (initial weight ~14 g) for 6 weeks. Fish from the PP0 treatment presented lower taurine and bile-acid concentrations compared with the FM treatment, and a downregulation of cyp7a1 and abcb11 was observed. Triolein catabolism decreased in PP0-fed fish, resulting in increased hepatic fat content and plasma triglycerides, while no effects on plasma cholesterol were observed. Taurine supplementation to plant-based diets resulted in a higher taurine accumulation in fish tissues, increased bile-acid concentration, and upregulation of cyp7a1 and abcb11. Hepatic fat content and plasma triglycerides
decreased with increasing dietary taurine supplementation. Taurine supplementation mitigated part of the negative effects of plant-based diets, leading to better lipid utilisation.
International Journal of Molecular Sciences, 2022
The present work aimed to study the role of dietary tryptophan supplementation in modulating the ... more The 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 toinflammation, 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 in-flammation. 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.
Animals, 2022
The sustainability of the Aquaculture industry relies on optimising diets to promote nitrogen ret... more The sustainability of the Aquaculture industry relies on optimising diets to promote nitrogen retention and maximise fish growth. The aim of this study was to assess how different dietary formulations influence the bioavailability and metabolic fate of distinct amino acids in gilthead seabream juveniles. Amino acids (lysine, tryptophan, and methionine) were selected based on their ketogenic and/or glucogenic nature. Seabream were fed practical diets with different protein (44 and 40%) and lipid contents (21 and 18%): 44P21L, 44P18L, 40P21L, and 40P18L. After three weeks of feeding, the fish were tube-fed the correspondent diet labelled with 14C-lysine, 14C-tryptophan, or 14C-methionine. The amino acid utilisation was determined based on the evacuation, retention in gut, liver, and muscle, and the catabolism of the tracer. The metabolic fate of amino acids was mainly determined by their nature. Tryptophan was significantly more evacuated than lysine or methionine, indicating a lower availability for metabolic purposes. Methionine was more retained in muscle, indicating its higher availability. Lysine was mainly catabolised, suggesting that catabolism is preferentially ketogenic, even when this amino acid is deficient in diets. This study underpins the importance of optimising diets considering the amino acids’ bioavailability and metabolic fate to maximise protein retention in fish.
O cultivo de larvas de peixes marinhos é caracterizado por altas mortalidades e por problemas de ... more O cultivo de larvas de peixes marinhos é caracterizado por altas mortalidades e por problemas de qualidade, nomeadamente malformações esqueléticas. A solução de parte destes problemas passa por uma melhor compreensão dos requisitos nutricionais. Este trabalho pretende fazer uma revisão de trabalhos recentes que demonstram como os aminoácidos, os ácidos gordos e a vitamina K, mas também o regime alimentar, podem influenciar a qualidade e a performance das larvas de peixes marinhos. Apesar de progressos recentes, o conhecimento sobre os requisitos nutricionais em proteínas e aminoácidos (AA) das larvas de peixes é ainda limitado. As principais diferenças em comparação com peixes maiores parecem ser uma menor capacidade de digerir e / ou absorver proteínas complexas. De facto, as larvas da maioria das espécies de peixes marinhos, e sobretudo nos primeiros dias de vida, possuem um trato digestivo simples e uma capacidade limitada para digerir proteínas. Assim, as dietas de larvas de peixes necessitam de ser ricas em proteína solúvel e proteínas complexas com baixa digestibilidade devem ser evitadas. Resultados recentes revelaram ainda que o peso molecular da fração proteica da dieta tem um forte efeito sobre a expressão do proteoma das larvas, com importantes implicações na qualidade e potencial de crescimento destas. Foi ainda demonstrado que desequilíbrios no perfil de AA indispensáveis das dietas de larvas de peixes levam a um maior catabolismo proteico, o que pode causar menores sobrevivências e uma maior incidência de malformações esqueléticas. As larvas de peixes marinhos têm altos requisitos em ácidos gordos essenciais (EFA), tais como DHA, EPA e ARA. Dietas deficientes nestes EFA afetam a sobrevivência, crescimento, pigmentação e resistência ao stress das larvas, devido a alterações na função das membranas celulares e/ou do metabolismo de eicosanóides e lípidos. Por exemplo, os níveis de ARA na dieta 2 afetam a resposta ao stress e o metabolismo lipídico, como demonstrado em estudos de expressão génica e de marcadores radioativos. No entanto, os requisitos em EFA de larvas de peixes marinhos parecem variar com a espécie. A vitamina K é uma vitamina lipossolúvel envolvida na coagulação do sangue e que desempenha um papel importante no metabolismo ósseo. Foi recentemente demonstrado que a suplementação da dieta de larvas de linguado em vitamina K leva a uma redução no número de peixes deformados bem como no número de deformidades por peixe, e ainda a alterações significativas da expressão do proteoma. Em resumo, está demonstrado que tanto a qualidade como a performance de larvas de peixes marinhos podem ser melhoradas através da otimização da dieta, quer através das dosagens de nutrientes específicos, quer da melhoria do regime alimentar.
... Lu??s Eug??nio Castanheira da Concei????o1, Cl??udia Arag??o1, Nad??ge Richard1, Sofia Engrol... more ... Lu??s Eug??nio Castanheira da Concei????o1, Cl??udia Arag??o1, Nad??ge Richard1, Sofia Engrola1, Paulo Gavaia1, Sara Mira1, Jorge Dias1 ... que estas t??m dificuldade em digerir dietas contendo prote??nas complexas, como ?? o caso das dietas contendo farinha de peixe. ...
Journal of Fish Biology, 2022
Methionine and taurine are amino acids (AA) that are usually deficient when fish meal is replace... more Methionine and taurine are amino acids (AA) that are usually deficient when fish meal
is replaced by plant proteins. In this study, three diets were tested in juvenile meagre
(initial weight: 13.4 g) for 8 weeks. The D1 diet had 0.2% methionine and 1% taurine
supplementation; the D2 and D3 diets had 0.6% methionine and 1% and 2% taurine
supplementation, respectively. The results showed that meagre fed the D1 diet had
lower specific growth rate (2.2 to 2.5), lower feed efficiency (0.9 to 1.2) and higher
food conversion rate (FCR, 1.1 to 0.8) as well as a lower activity of the alanine aminotransferase (ALAT) enzyme. Furthermore, a higher recruitment of muscle fibres (46% compared to 36%) as well as a higher fibre density was observed (1019 compared to 870 fibres mm–2). This study shows that meagre requires a sufficient quantity of
methionine in plant-based diets to avoid a reduction in fish performance. Furthermore,
taurine supplementation in the D1 diet was not able to mitigate the effects of
methionine deficiency. A higher taurine supplementation did not improve meagre
performance.
Aquaculture Nutrition, 2020
To support the expected increase in aquaculture production during the next years, a wider range ... more To support the expected increase in aquaculture production during the next years,
a wider range of alternative ingredients to fishmeal is needed, towards contributing
to an increase in production sustainability. This study aimed to test diets formulated
with non‐conventional feed ingredients on gilthead seabream (Sparus aurata) growth
performance, feed utilization, apparent digestibility of nutrients and nutrient outputs
to the environment. Four isonitrogenous and isoenergetic diets were formulated:
a control diet (CTRL) similar to a commercial feed and three experimental diets
containing, as main protein sources, plant by‐products, glutens and concentrates
(PLANT); processed animal proteins (PAP); or micro/macroalgae, insect meals and
yeast (EMERG). Diets were tested in triplicate during 80 days. The EMERG treatment
resulted in lower fish growth performance, higher FCR and lower nutrient and energy
retentions than the other treatments. The lowest protein digestibility was found
for the EMERG diet, which caused increased nitrogen losses. The PLANT and PAP
treatments resulted in better fish growth performance, higher nutrient and energy
retentions, and lower FCR than the CTRL treatment. The significant improvement
in FCR found for fish fed PLANT and PAP diets and the high protein digestibility of
these diets contribute towards minimizing the environmental impacts of seabream
production.
Aquaculture, 2017
Parental and early-feeding effects of dietary methionine in rainbow trout (Oncorhynchus mykiss
Animals, 2022
Aquaculture has been challenged to find alternative ingredients to develop innovative feed formul... more Aquaculture 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.
Aquaculture, 2017
Recent studies reported positive effects of taurine supplementation to plant protein-based diets ... more Recent studies reported positive effects of taurine supplementation to plant protein-based diets on fish growth performance and feed conversion ratio but the mechanisms involved remain unclear. The objective of this work was to provide a first insight on the importance of taurine on dietary protein and lipid absorption and
utilisation, in Senegalese sole (Solea senegalensis) juveniles fed plant-based diets. Seven practical diets were tested: a fishmeal-based diet (FM) and a plant protein-based formula (PP85) to which taurine was added in graded levels: 0.2% (TAU1), 0.3% (TAU2), 0.4% (TAU3), 0.7% (TAU4) and 1.5% (TAU5). Short-term metabolic trials were
performed by tube-feeding the different experimental diets labelled with different tracers: 14C-taurine, 14C-triolein (as tracer of dietary triacylglycerol) and a mixture of 14C-amino acids. Feeding sole juveniles with the PP85 diet affected taurine metabolism, since a higher proportion of dietary taurine was directed to gall bladder
and probably used for bile salt synthesis. Consistent with this, fish receiving the plant-based low taurine-content diets (PP85 and TAU1) displayed a poor triacyglycerol digestion capacity. A higher proportion of 14C-amino acids was retained in fish muscle when fed the TAU5 compared to the PP85 diet. These short-term trials suggested that taurine supplementation to a plant-based diet might be beneficial to sole performance by enhancing bile salt synthesis and triacylglycerol digestion as well as muscle amino acid retention. However, this dietary supplementation should be tested in long-term trials to verify the effect on fish growth and to assess the beneficial effects on protein and lipid metabolism suggested here.
한국수산과학회 양식분과 학술대회, May 1, 2015
Aquaculture Nutrition
The dietary protein to energy ratio (P/E) has proven to influence protein utilization and/or grow... more The dietary protein to energy ratio (P/E) has proven to influence protein utilization and/or growth in several fish species. This study intended to unravel the bioavailability and metabolic fate of lysine and methionine in gilthead seabream (Sparus aurata) juveniles fed plant diets with different P/E ratios. Seabream juveniles were fed two isonitrogenous diets (45% crude protein) differing in crude lipids (20 and 14%): LowP/E ( P / E ratio = 20.0 mg protein k J − 1 ) and HighP/E ( P / E ratio = 21.4 mg protein k J − 1 ). After three weeks, fish ( 11.6 ± 4.3 g ) were tube-fed the respective diet labelled with 14C-protein (L-amino acid mixture), 14C-lysine, or 14C-methionine. Protein, lysine, and methionine utilization were determined based on the proportion of 14C-amino acid evacuated, retained in the free or protein-bound fraction of liver and muscle, or catabolized. This study revealed that a decrease in P/E ratio resulted in lower amino acid evacuation (p <0.0...
Aquaculture, Oct 1, 2018
The regulatory role of taurocholic acid (TC) and taurolithocholic acid (TLC) in ion transport was... more The regulatory role of taurocholic acid (TC) and taurolithocholic acid (TLC) in ion transport was investigated with the short-circuit current (Isc) technique in the intestine of Senegalese sole (Solea senegalensis). Under voltage clamp conditions, Isc was stable for over 3 h and averaged −15.42 ± 2.75 μA/cm 2 and −65.28 + 7.69 μA/cm 2 in the anterior and posterior intestine, respectively. Only bumetanide (200 μM), a loop diuretic that inhibits Na + /K + /2Cl − co-transporters, inhibited the absorptive Isc, and apical application of NPPB (200 μM), EIPA (200 μM), glibenclamide (200 μM) and DIDS (200 μM) were without effect in the absorptive current. Apical application of TC and TLC induced rapid (< 1 min) increases in the absorptive current in the anterior and the posterior intestine. The responses were dose dependent in the range of physiological levels of TC or TLC previously detected in the intestine of Senegalese sole, 0.4-4 mM, with higher responses in the posterior intestine at the same doses. The response to apical application of TC and TLC was completely abolished by bumetanide (200 μM). In addition, the effect of TC or TLC in preparations with bilateral reduction of chloride (from 146 to 6 mM) in the chamber saline was reduced by 80%. Conclusions of this study indicate that the bile salts TC and TLC alter ionic transport in the intestine of marine fish enhancing the absorptive pathway. These changes revealed by regulation of Isc are characterized by their dose-dependent action, intestinal region dependency, reversibility, chloride dependence and bumetanide sensitivity.
Journal of Aquaculture Research & Development, 2018
Deoxynivalenol (DON), a Fusarium mycotoxin, is one of the most prevalent mycotoxins in aquafeeds.... more Deoxynivalenol (DON), a Fusarium mycotoxin, is one of the most prevalent mycotoxins in aquafeeds. The toxicokinetics of DON are rarely studied in aquatic species. The present study used juvenile rainbow trout (Oncorhynchus mykiss) with a mean initial body weight of 7.72 ± 1.42 g in order to evaluate the pharmacokinetic behaviour and the metabolization of radiolabelled DON ([ 3 H]-DON). In a first trial, 30 fish were tube-fed with four pellets containing a total of 125 ± 0.019 ng of [ 3 H]-DON. At different sampling time points after feeding (1 h, 3 h, 6 h, 12 h or 24 h), the tissue distribution of the [ 3 H]-DON was assessed by liquid scintillation counting. In a second trial, five fish were tube-fed four pellets containing a total of 663 ng of unlabelled-DON. Twenty-four hours after feeding, metabolites of DON excreted into the water were analysed by LC-MS/MS. [ 3 H]-DON was detected in fish liver one hour after tube-feeding, indicating a rapid absorption of DON. In the first hour, [ 3 H]-DON achieved its maximum in the gastro-intestinal tract (GIT) (20.56 ± 8.30 ng). However, 6.19 ± 0.83 ng of [ 3 H]-DON was also detected in the water at this sampling time point. The fast excretion of [ 3 H]-DON (above the average gastric emptying time of trout) might be related to its high-water solubility and consequent excretion with the fluid phase of the chyme. The amount of [ 3 H]-DON in the GIT was stable during the first six hours. Such long transit time of DON through the GIT increases the potential for damage and absorption. The period between six and twelve hours seems to be the turning point in terms of DON excretion. Twelve hours after tube-feeding, the trout excreted 50.71 ± 22.17% of the tube-fed DON amount into water, while at the previous sampling time point (six hours) only 11.03 ± 6.09% were detected. These data suggest that an effective method for gastrointestinal DON detoxification in trout requires a period of action lower than six hours. In the present trial, no DON metabolites were detected in water.
Journal of Marine Science and Engineering, 2023
Mussel meal (species Perna perna) was evaluated as a potential feed additive for whiteleg shrimp ... more Mussel meal (species Perna perna) was evaluated as a potential feed additive for whiteleg shrimp (Litopenaeus vannamei) diets to improve growth and cold resistance. Five experimental diets (0, 1, 2, 3 and 4% of mussel meal inclusion) were tested in quadruplicate in whiteleg shrimp, using twenty polyethylene tanks of 400 L. Each tank was stocked with 40 shrimp (3.5 ± 0.5 g), filled with seawater and kept under constant aeration and a temperature of 28.4 ± 0.4 °C. After 8 weeks, the growth and feed efficiency of the shrimp were evaluated, and a thermal shock was administered. The shrimp that were fed with the addition of 3 or 4% mussel meal in their diets showed similar results as the control (0% inclusion), while the addition of 1 or 2% mussel meal in the diet resulted in a significantly higher final weight, weight gain and relative growth rate and a lower feed conversion ratio. Further, no differences were observed in thermal shock resistance and survival among the treatments. In conclusion, mussel meal can be used as a feed additive in whiteleg shrimp diets to improve growth, and quadratic regression models indicate that the best levels of inclusion range from 1.73 to 2.00%
Animals, 2023
Taurine is a sulphur-containing amino acid with important physiological roles and a key compound ... more Taurine is a sulphur-containing amino acid with important physiological roles and a key compound for the synthesis of bile salts, which are essential for the emulsion and absorption of dietary lipids. This study aimed to evaluate the effects of taurine supplementation to low-fishmeal diets on the metabolism of taurine, bile acids, and lipids of Senegalese sole. A fishmeal (FM) and a plant-protein-based (PP0) diet were formulated, and the latter was supplemented with taurine at 0.5 and 1.5% (diets PP0.5 and PP1.5). Diets were assigned to triplicate tanks containing 35 fish (initial weight ~14 g) for 6 weeks. Fish from the PP0 treatment presented lower taurine and bile-acid concentrations compared with the FM treatment, and a downregulation of cyp7a1 and abcb11 was observed. Triolein catabolism decreased in PP0-fed fish, resulting in increased hepatic fat content and plasma triglycerides, while no effects on plasma cholesterol were observed. Taurine supplementation to plant-based diets resulted in a higher taurine accumulation in fish tissues, increased bile-acid concentration, and upregulation of cyp7a1 and abcb11. Hepatic fat content and plasma triglycerides
decreased with increasing dietary taurine supplementation. Taurine supplementation mitigated part of the negative effects of plant-based diets, leading to better lipid utilisation.
International Journal of Molecular Sciences, 2022
The present work aimed to study the role of dietary tryptophan supplementation in modulating the ... more The 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 toinflammation, 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 in-flammation. 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.
Animals, 2022
The sustainability of the Aquaculture industry relies on optimising diets to promote nitrogen ret... more The sustainability of the Aquaculture industry relies on optimising diets to promote nitrogen retention and maximise fish growth. The aim of this study was to assess how different dietary formulations influence the bioavailability and metabolic fate of distinct amino acids in gilthead seabream juveniles. Amino acids (lysine, tryptophan, and methionine) were selected based on their ketogenic and/or glucogenic nature. Seabream were fed practical diets with different protein (44 and 40%) and lipid contents (21 and 18%): 44P21L, 44P18L, 40P21L, and 40P18L. After three weeks of feeding, the fish were tube-fed the correspondent diet labelled with 14C-lysine, 14C-tryptophan, or 14C-methionine. The amino acid utilisation was determined based on the evacuation, retention in gut, liver, and muscle, and the catabolism of the tracer. The metabolic fate of amino acids was mainly determined by their nature. Tryptophan was significantly more evacuated than lysine or methionine, indicating a lower availability for metabolic purposes. Methionine was more retained in muscle, indicating its higher availability. Lysine was mainly catabolised, suggesting that catabolism is preferentially ketogenic, even when this amino acid is deficient in diets. This study underpins the importance of optimising diets considering the amino acids’ bioavailability and metabolic fate to maximise protein retention in fish.
O cultivo de larvas de peixes marinhos é caracterizado por altas mortalidades e por problemas de ... more O cultivo de larvas de peixes marinhos é caracterizado por altas mortalidades e por problemas de qualidade, nomeadamente malformações esqueléticas. A solução de parte destes problemas passa por uma melhor compreensão dos requisitos nutricionais. Este trabalho pretende fazer uma revisão de trabalhos recentes que demonstram como os aminoácidos, os ácidos gordos e a vitamina K, mas também o regime alimentar, podem influenciar a qualidade e a performance das larvas de peixes marinhos. Apesar de progressos recentes, o conhecimento sobre os requisitos nutricionais em proteínas e aminoácidos (AA) das larvas de peixes é ainda limitado. As principais diferenças em comparação com peixes maiores parecem ser uma menor capacidade de digerir e / ou absorver proteínas complexas. De facto, as larvas da maioria das espécies de peixes marinhos, e sobretudo nos primeiros dias de vida, possuem um trato digestivo simples e uma capacidade limitada para digerir proteínas. Assim, as dietas de larvas de peixes necessitam de ser ricas em proteína solúvel e proteínas complexas com baixa digestibilidade devem ser evitadas. Resultados recentes revelaram ainda que o peso molecular da fração proteica da dieta tem um forte efeito sobre a expressão do proteoma das larvas, com importantes implicações na qualidade e potencial de crescimento destas. Foi ainda demonstrado que desequilíbrios no perfil de AA indispensáveis das dietas de larvas de peixes levam a um maior catabolismo proteico, o que pode causar menores sobrevivências e uma maior incidência de malformações esqueléticas. As larvas de peixes marinhos têm altos requisitos em ácidos gordos essenciais (EFA), tais como DHA, EPA e ARA. Dietas deficientes nestes EFA afetam a sobrevivência, crescimento, pigmentação e resistência ao stress das larvas, devido a alterações na função das membranas celulares e/ou do metabolismo de eicosanóides e lípidos. Por exemplo, os níveis de ARA na dieta 2 afetam a resposta ao stress e o metabolismo lipídico, como demonstrado em estudos de expressão génica e de marcadores radioativos. No entanto, os requisitos em EFA de larvas de peixes marinhos parecem variar com a espécie. A vitamina K é uma vitamina lipossolúvel envolvida na coagulação do sangue e que desempenha um papel importante no metabolismo ósseo. Foi recentemente demonstrado que a suplementação da dieta de larvas de linguado em vitamina K leva a uma redução no número de peixes deformados bem como no número de deformidades por peixe, e ainda a alterações significativas da expressão do proteoma. Em resumo, está demonstrado que tanto a qualidade como a performance de larvas de peixes marinhos podem ser melhoradas através da otimização da dieta, quer através das dosagens de nutrientes específicos, quer da melhoria do regime alimentar.
... Lu??s Eug??nio Castanheira da Concei????o1, Cl??udia Arag??o1, Nad??ge Richard1, Sofia Engrol... more ... Lu??s Eug??nio Castanheira da Concei????o1, Cl??udia Arag??o1, Nad??ge Richard1, Sofia Engrola1, Paulo Gavaia1, Sara Mira1, Jorge Dias1 ... que estas t??m dificuldade em digerir dietas contendo prote??nas complexas, como ?? o caso das dietas contendo farinha de peixe. ...
Journal of Fish Biology, 2022
Methionine and taurine are amino acids (AA) that are usually deficient when fish meal is replace... more Methionine and taurine are amino acids (AA) that are usually deficient when fish meal
is replaced by plant proteins. In this study, three diets were tested in juvenile meagre
(initial weight: 13.4 g) for 8 weeks. The D1 diet had 0.2% methionine and 1% taurine
supplementation; the D2 and D3 diets had 0.6% methionine and 1% and 2% taurine
supplementation, respectively. The results showed that meagre fed the D1 diet had
lower specific growth rate (2.2 to 2.5), lower feed efficiency (0.9 to 1.2) and higher
food conversion rate (FCR, 1.1 to 0.8) as well as a lower activity of the alanine aminotransferase (ALAT) enzyme. Furthermore, a higher recruitment of muscle fibres (46% compared to 36%) as well as a higher fibre density was observed (1019 compared to 870 fibres mm–2). This study shows that meagre requires a sufficient quantity of
methionine in plant-based diets to avoid a reduction in fish performance. Furthermore,
taurine supplementation in the D1 diet was not able to mitigate the effects of
methionine deficiency. A higher taurine supplementation did not improve meagre
performance.
Aquaculture Nutrition, 2020
To support the expected increase in aquaculture production during the next years, a wider range ... more To support the expected increase in aquaculture production during the next years,
a wider range of alternative ingredients to fishmeal is needed, towards contributing
to an increase in production sustainability. This study aimed to test diets formulated
with non‐conventional feed ingredients on gilthead seabream (Sparus aurata) growth
performance, feed utilization, apparent digestibility of nutrients and nutrient outputs
to the environment. Four isonitrogenous and isoenergetic diets were formulated:
a control diet (CTRL) similar to a commercial feed and three experimental diets
containing, as main protein sources, plant by‐products, glutens and concentrates
(PLANT); processed animal proteins (PAP); or micro/macroalgae, insect meals and
yeast (EMERG). Diets were tested in triplicate during 80 days. The EMERG treatment
resulted in lower fish growth performance, higher FCR and lower nutrient and energy
retentions than the other treatments. The lowest protein digestibility was found
for the EMERG diet, which caused increased nitrogen losses. The PLANT and PAP
treatments resulted in better fish growth performance, higher nutrient and energy
retentions, and lower FCR than the CTRL treatment. The significant improvement
in FCR found for fish fed PLANT and PAP diets and the high protein digestibility of
these diets contribute towards minimizing the environmental impacts of seabream
production.
Aquaculture, 2017
Parental and early-feeding effects of dietary methionine in rainbow trout (Oncorhynchus mykiss
Animals, 2022
Aquaculture has been challenged to find alternative ingredients to develop innovative feed formul... more Aquaculture 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.
Aquaculture, 2017
Recent studies reported positive effects of taurine supplementation to plant protein-based diets ... more Recent studies reported positive effects of taurine supplementation to plant protein-based diets on fish growth performance and feed conversion ratio but the mechanisms involved remain unclear. The objective of this work was to provide a first insight on the importance of taurine on dietary protein and lipid absorption and
utilisation, in Senegalese sole (Solea senegalensis) juveniles fed plant-based diets. Seven practical diets were tested: a fishmeal-based diet (FM) and a plant protein-based formula (PP85) to which taurine was added in graded levels: 0.2% (TAU1), 0.3% (TAU2), 0.4% (TAU3), 0.7% (TAU4) and 1.5% (TAU5). Short-term metabolic trials were
performed by tube-feeding the different experimental diets labelled with different tracers: 14C-taurine, 14C-triolein (as tracer of dietary triacylglycerol) and a mixture of 14C-amino acids. Feeding sole juveniles with the PP85 diet affected taurine metabolism, since a higher proportion of dietary taurine was directed to gall bladder
and probably used for bile salt synthesis. Consistent with this, fish receiving the plant-based low taurine-content diets (PP85 and TAU1) displayed a poor triacyglycerol digestion capacity. A higher proportion of 14C-amino acids was retained in fish muscle when fed the TAU5 compared to the PP85 diet. These short-term trials suggested that taurine supplementation to a plant-based diet might be beneficial to sole performance by enhancing bile salt synthesis and triacylglycerol digestion as well as muscle amino acid retention. However, this dietary supplementation should be tested in long-term trials to verify the effect on fish growth and to assess the beneficial effects on protein and lipid metabolism suggested here.