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Being a rich source of important nutrients, including highly digestible proteins, vitamins (A, D3), trace minerals (iodine, selenium) and n-3 long chain polyunsaturated fatty acids (n-3 LCPUFA), fish consumption is generally regarded as part of a healthy dietary pattern. Exogenous feeding in aquaculture unlocks the possibility to tailor fish composition with healthy valuable nutrients. However, the use of supplements in the fish feed during fish production may undermine consumers' perception opinion of these fortified products. The effectiveness success of a functional food is a combination of its efficacy and meeting consumers' expectations. A self-administered questionnaire was designed to assess consumers' preferences regarding fish consumption, and their perception of farmed seabream as a functional food. A high consumption rate of fish, (between daily, and a minimum of three times a week), was reported by 47% of the respondents. Freshness, flavour, quality and price were the four most valued attributes. Good acceptance of the fish fortification concept was observed (53%), as well as positive receptiveness to its consumption (50%). Anti-oxidants and omega-3 fatty acids were the most accepted compounds for fish fortification. Additionally, two consumer groups were established based on their high (HIG) or low (LIG) interest in fish origin (wild vs aquaculture). The LIG was more receptive to all aspects of fish fortification and showed willingness to buy and consume it. This suggests that fortified fish could be targeted to the LIG profile group, which represents 42% of the studied population. With appropriate communication, farmed fish may be a good candidate for functional food. PROMAR Program (Portugal) [31-03-05-FEP-0060] FEDER fundsEuropean Union (EU) COST Action Feed for Health [FA 0802] FCT doctoral grant, Portugal [SFRH/BD/73452/2010]

International audience; Environmental sustainability of aquaculture is a complex issue involving effects at local (e.g. benthic deterioration), regional (e.g. eutrophication) and global (e.g. catches for feed production) scales as a consequence of farming operations (e.g. waste emissions) and industrial processes involved in the product value chain. Integrating these effects using a holistic and multi-scale framework is essential to assess the environmental sustainability of innovative production systems such as Integrated Multi-Trophic Aquaculture (IMTA), in which organisms of different trophic levels are co-cultured on the same farm to minimize aquaculture waste. The environmental performances of theoretical production scenarios of red drum (Sciaenops ocellatus) sea cage monoculture and an open-water IMTA co-culturing of red drum and sea cucumber (Holothuria scabra) were assessed with mathematical models at local and global scales. First, the particulate waste bioremediation potential of sea cucumber production was estimated using an individual-based bioenergetic model. Second, environmental impacts of the monoculture and the IMTA systems were estimated and compared using life cycle assessment (LCA), calculated per kg of edible protein and t of product, including uncertainty analysis. Given the current limits to stocking density observed for sea cucumbers, its co-culture in sea cages suspended beneath finfish nets may decrease slightly (by 0.73%) farm net particulate waste load and benthic impact. The monoculture and IMTA showed little difference in impact because of the large difference in production scales of finfish and sea cucumber species. Removing 100% of finfish feces particulate waste requires cultivating sea cucumber at scale similar to that of finfish (1.3 kg of sea cucumber per kg of finfish). Nonetheless, LCA showed trends in IMTA performance: lower eutrophication impact and net primary production use but higher cumulative energy demand and climate change impacts, generating an impact transfer between categories. Intensification of sea cucumber culture could increase local and global environmental benefits, but further research is necessary to design rearing units that can optimize production and/or bioremediation and that can be practically integrated into existing finfish monoculture units. The methodology defined here can be a powerful tool to predict the magnitude of environmental benefits that can be expected from new and complex production systems and to show potential impact transfer between spatial scales. We recommend applying it to other IMTA systems and species associations and including socio-economic criteria to fully assess the sustainability of future seafood production systems.

WOS: 000442210300011, 30151043, Science Citation Index Expanded, Unraveling adaptive genetic variation represents, in addition to the estimate of population demographic parameters, a cornerstone for the management of aquatic natural living resources, which, in turn, represent the raw material for breeding programs. The turbot (Scophthalmus maximus) is a marine flatfish of high commercial value living on the European continental shelf. While wild populations are declining, aquaculture is flourishing in southern Europe. We evaluated the genetic structure of turbot throughout its natural distribution range (672 individuals; 20 populations) by analyzing allele frequency data from 755 single nucleotide polymorphism discovered and genotyped by double-digest RAD sequencing. The species was structured into four main regions: Baltic Sea, Atlantic Ocean, Adriatic Sea, and Black Sea, with subtle differentiation apparent at the distribution margins of the Atlantic region. Genetic diversity and effective population size estimates were highest in the Atlantic populations, the area of greatest occurrence, while turbot from other regions showed lower levels, reflecting geographical isolation and reduced abundance. Divergent selection was detected within and between the Atlantic Ocean and Baltic Sea regions, and also when comparing these two regions with the Black Sea. Evidence of parallel evolution was detected between the two low salinity regions, the Baltic and Black seas. Correlation between genetic and environmental variation indicated that temperature and salinity were probably the main environmental drivers of selection. Mining around the four genomic regions consistently inferred to be under selection identified candidate genes related to osmoregulation, growth, and resistance to diseases. The new insights are useful for the management of turbot fisheries and aquaculture by providing the baseline for evaluating the consequences of turbot releases from restocking and farming., 7th Framework Programme for research (FP7) under "Knowledge-Based Bio-Economy - KBBE", Theme 2: "Food, Agriculture and fisheries, and Biotechnologies" [FP7-KBBE-2012-6-singlestage, 311920]; Spanish Regional Government Xunta de Galicia [GRC2014/010], 7th Framework Programme for research (FP7) under "Knowledge-Based Bio-Economy - KBBE", Theme 2: "Food, Agriculture and fisheries, and Biotechnologies" Project identifier: FP7-KBBE-2012-6-singlestage, Grant/Award Number: 311920; Spanish Regional Government Xunta de Galicia, Grant/Award Number: GRC2014/010

WOS: 000414941000006, A 12-week feeding trial was conducted to estimate the effects of supplemented amino acids (lysine and methionine) with different dietary protein levels on growth, haematology and liver histology in meagre (Argyrosomus regius) at two different sizes: fingerling (15.2g) and juvenile (44.4g). Six practical diets were prepared, and three of these practical diets were formulated with 40 (P40), 44 (P44) and 48% (P48) crude protein without supplementation of amino acids. Other three diets having same protein levels were supplemented with lysine and methionine (P40AA, P44AA and P48AA) to bring these amino acids level up to that estimated to be at the least in the 48% protein diet. Final mean weight (FMW) and specific growth rate (SGR) of P48AA in fingerlings were higher than that of 40AA. According to FMW and SGR of juveniles, there was interaction found between dietary protein levels and the supplementation of amino acids. The FMW and SGR of meagre fed P44AA were higher than that of fish fed the other diets, except fish fed the P48. Economic profit index, packed cell volume and haemoglobin for juvenile meagre were significantly improved with the dietary protein level and amino acid supplementation. The liver tissues of the P48 group in both sizes displayed better structure compared with the other groups. In conclusion, dietary crude protein content of practical diets for juvenile meagre could be reduced from 48% to 44% by adding essential amino acids with an enhancement in growth, health and economic profit., T.C. Gida Tarim ve Hayvancilik Bakanligi [13/RD/31], T.C. Gida Tarim ve Hayvancilik Bakanligi, Grant/Award Number: 13/R&D/31

European aquaculture is an industry with a high sustainability profile contributing to the supply of safe seafood. However, several diseases can affect farmed fish and it is imperative to find alternatives for chemotherapeutic treatments when disease outbreaks occur. Maintenance of health through nutrition is well-establish in modern animal farming, and amino acids (AA) are promising candidates as functional additives to improve fish health. Therefore, the goal of this research is to provide a better understanding of the influence of tryptophan supplementation on nutritional condition and immune mechanisms in fish. Triplicate groups of fish (13.3 ± 0.3g) previously fed with a fishmeal-based diet were either fed a control diet with an extreme formulation (0% fishmeal) but meeting the AA requirements (CTRL), or the SUP diet, formulated as the CTRL with an increase in tryptophan (TRP) content. After 2 and 13 weeks of feeding, head-kidney (HK), liver (L) and white skeletal muscle (WSM) were collected for gene expression, whereas plasma was suited for humoral immune parameters. A holistic approach using transcriptomic, humoral and zootechnical parameters was undertaken. The expression of 29–31 genes for WSM, L or HK confirms an effect due to the treatment across time. A two-way ANOVA analysis revealed that 15–24 genes varied significantly depending on the tissue, and the multivariate analysis by means of PLS-DA explained (R) and predicted (Q) with four components up to 93% and 78% of total variance, respectively. Component 1 (R = 50.06%) represented the time effects, whereas components 2 (24.36%) and 3 (13.89%) grouped fish on the basis of dietary treatment, at early sampling. The HK results in particular suggest that fish fed SUP diet displayed an immunostimulated state at 2 weeks. No major differences were observed in plasma humoral parameters, despite an increase in antiprotease and peroxidase activities after 13 weeks regardless of dietary treatment. These results suggest that tryptophan supplementation may improve the seabream immune status after 2 weeks. Hence, the use of functional feeds is especially relevant during a short-term feeding period before a predictable stressful event or disease outbreak, considering that these putative advantageous effects seem to disappear after a 13 weeks feeding period., This work was partially supported by Projects ALISSA (reference ALG-01-0247-FEDER-3520), UID/Multi/04423/2019, IF/00197/2015 and IF/00482/2014, financed by Portugal and the European Union through FEDER, COMPETE 2020 and CRESC Algarve 2020, in the framework of Portugal 2020, and through the COMPETE and Operational Human Potential Programmes and national funds through Fundação para a Ciência e a Tecnologia (FCT, P ortugal). L. Ramos-Pinto, S. Engrola and B. Costas were supported by FCT, Portugal (PD/BDE/114436/2016, IF/00482/2014 and IF/00197/2015, respectively).

Larvae and early juveniles of fast-growing fish species show tremendous growth potential, leading to higher requirements for protein, high-unsaturated fatty acids, and other nutrients. Several commercial weaning diets with relatively high success have been developed for low/moderate-growing species; however, additional challenges are outlined to meet growth potential and energy requirements of such fast-growing species. The objective of the present study was to evaluate two commercial microdiets for marine fish, one having simultaneously a very high protein and high lipid contents (HIGH), and another (MOD) with a high protein and moderate lipid content, in a growth performance trial with greater amberjack post-larvae from 33 to 78 days after hatching. Moreover, histological preparations of liver, anterior and posterior intestine were assessed for hepatic and intestinal lipid inclusions quantification and gut epithelial brush height measurement. Activities of the digestive enzymes: pepsin, trypsin, chymotrypsin, lipase and amylase were also analyzed. Post-larvae fed HIGH microdiet exhibited higher final weight and lower feed conversion ratio that those fed on MOD microdiet. Liver displayed a higher level of lipid inclusions for the MOD diet than for HIGH diet. Moreover, enterocytes of posterior intestine presented a much higher level of supranuclear vacuoles for the HIGH diet compared to MOD diet. The lower Trypsin/Chymotrypsin ratio observed at the end of the experiment in larvae fed on MOD diet may indicate a deficiency in protein of this diet. Together, these results support that larvae of greater amberjack, and likely other fast-growing marine fish species, require high protein–high lipid microdiets. The use of microdiets developed targeting slower growing marine species may lead to sub-optimal performances in fast-growing larvae., This study was undertaken by Project WEANTUNA supported by Eurostars (E! 7994) and co-financed by FEDER through PO Algarve 21 in the framework of QREN 2007-2013 (30200).

Over the next century, climate change of anthropogenic origin is a major threat to global biodiversity. We show here that developmental temperature can have significant effects on zebrafish cardiac anatomy and swimming performance. Zebrafish embryos were subjected to three developmental temperature treatments (TD = 24, 28 or 32 °C) up to metamorphosis and then all maintained under common conditions (28 °C) to adulthood. We found that developmental temperature affected cardiac anatomy of juveniles and adults even eight months after the different thermal treatments had been applied. The elevation of TD induced a significant increase of the ventricle roundness in juvenile (10% increase) and male (22% increase), but not in female zebrafish. The aerobic exercise performance of adult zebrafish was significantly decreased as TD elevated from 24 to 32 °C. Gene expression analysis that was performed at the end of the temperature treatments revealed significant up-regulation of nppa, myh7 and mybpc3 genes at the colder temperature. Our work provides the first evidence for a direct link between developmental temperature and cardiac form at later life-stages. Our results also add to the emerging rationale for understanding the potential effects of global warming on how fish will perform in their natural environment.

The present study aims at identifying the lowest number of fish (European seabass) that could be used for monitoring and/or experimental purposes in small-scale fish facilities by quantifying the effect that the number of individuals has on the Shannon entropy (SE) of the trajectory followed by the shoal's centroid. Two different experiments were performed: (i) one starting with 50 fish and decreasing to 25, 13, and 1 fish, and (ii) a second experiment starting with one fish, adding one new fish per day during 5 days, ending up with five fish in the tank. The fish were recorded for 1h daily, during which time a stochastic event (a hit in the tank) was introduced. The SE values were calculated from the images corresponding to three arbitrary basal (shoaling) periods of 3.5 min prior to the event, and to the 3.5 min period immediately after the event (schooling response). Taking both experiments together, the coefficient of variation (CV) of the SE among measurements was largest for one fish systems (CV 37.12 and 17.94% for the daily average basal and response SE, respectively) and decreased concomitantly with the number of fish (CV 8.6-10% for the basal SE of 2 to 5 fish systems and 5.86, 2.69, and 2.31% for the basal SE of 13, 25, and 50 fish, respectively). The SE of the systems kept a power relationship with the number of fish (basal: R-2 = 0.93 and response: R-2 = 0.92). Thus, 5-13 individuals should be the lowest number for a compromise between acceptable variability (< 10%) in the data and reduction in the number of fish. We believe this to be the first scientific work made to estimate the minimum number of individuals to be used in subsequent experimental (including behavioral) studies using shoaling fish species that reaches a compromise between the reduction in number demanded by animal welfare guidelines and a low variability in the fish system's response. The work was financed through grant nos. CTM2012-40203-C02-01 (project BMW) and RTC-2014-2837-2 (project Selatun), both from the Spanish Ministry of Economy and Competitiveness (http://www.mineco.gob.es) and by grant no. KK-2016/00057 (project Maromega) Elkartek, from the Basque Government-Eusko Jaurlaritza.

00004 ăWOS:000367853300006; International audience; This study examined the effect of a commercial mix of Bacillus sp. on survival, growth and digestive enzyme activities of Florida pompano, red drum and common snook. Larvae were fed either live feed enriched with Algamac 3050 (Control), Algamac 3050 and probiotics (PB), or the previous diet combined with a daily addition of probiotics to the tank water (PB+). Survival was not affected by the treatments for any of the species. At the end of the pompano and snook trial, standard lengths of larvae from the PB and PB+ treatments were significantly greater than for the control larvae. Microbiological analyses were performed at the end of the pompano trial, and numbers of presumptive Vibrio were not a concern in the system. For both pompano and snook, trypsin-specificactivity was higher in PB and PB+ larvae compared with the control larvae. Similarly, alkaline phosphatase activity was higher for the pompano larvae fed the PB and PB+ treatments and for the snook larvae fed the PB+ treatment compared with the control larvae. This experiment suggests that a mix of Bacillus sp. can promote growth through an early maturation of the digestive system during the early larval stages of pompano and snook.

European aquaculture industry should be at the forefront of sustainable development, providing healthy and safe food of the highest quality to the consumer, through an environmentally sound approach. The purpose of this review was to explore in what way the current drive for sustainability has affected what the consumer perceives as quality in fish, specifically in gilthead seabream, one of the most important farmed species in the Mediterranean. It focuses on nutritional aspects such as fish meal and fish oil replacement, quality tailoring through finishing strategies, the influence of different farming systems and the effect of slaughter stress on seabream quality. In general, fish meal and fish oil replacement with vegetable ingredients will result in changes in the fatty acid profile of the fillets, and consequently the potential health benefits seabream offers to the consumer. While organoleptic properties suffer little change, the impact of these ingredients on welfare has not been fully investigated. Further studies are also needed to evaluate the effect of land animal ingredients on seabream quality. In either case, although finishing strategies to restore essential fatty acids are not completely effective, seabream can still retain a high nutritional value. Information on the use of dietary supplements as finishing strategies is still extremely scarce. Regarding fish welfare, the high densities practised in intensive production systems pose concerns which warrant further research in this area. Furthermore, new alternatives for common harvesting and slaughter methods are needed to improve welfare, as traditional methods are clearly stressful. FCT, Portugal [SFRH/BD/40886/2007, SFRH/BD/41392/2007] info:eu-repo/semantics/publishedVersion

7 Figuras.-- 3 Tablas, Given its complex metamorphosis and digestive system ontogeny, Senegalese sole larvae capacity to digest and utilize dietary protein is likely to change throughout development. In the present study, we hypothesized that the manipulation of dietary protein complexity may affect Senegalese sole larvae capacity to digest, absorb and retain protein during metamorphosis, as well as the mRNA expression of genes encoding for the precursors of proteolytic enzymes of the digestive tract and the enterocyte peptide transporter PepT1, which may have further impact on somatic growth. Three diets were formulated using approximately the same practical ingredients, except for the main protein source. The Intact diet protein content was mostly based on intact plant protein where the target peptide molecular weight (MW) would be > 70 kDa. The PartH diet protein fraction was mostly based on a protein hydrolysate with a high content of 5–70 kDa peptides. The HighH diet protein fraction was mostly based on a protein hydrolysate with a high content of 5 kDa peptides. A growth trial was performed with larvae reared at 19 °C under a co-feeding regime from mouth opening. The transcription of pga, tryp1c, ialp, ampn and pepT1 (encoding respectively for PepsinogenA, Trypsinogen1C, Intestinal alkaline phosphatase, Aminopeptidase N and for the enterocyte peptide transporter 1) was quantified by qPCR, during the metamorphosis climax (16 DAH) and after the metamorphosis was completed (28 DAH). An in vivo method of controlled tube-feeding was used to assess the effect on the larvae capacity to utilize polypeptides with different MW (1.0 and 7.2 kDa) representing a typical peptide MW of each of the hydrolysates included in the diets. The PartH diet stimulated growth in metamorphosing larvae (16 DAH), whereas the Intact diet stimulated growth after 36 DAH. The Intact diet stimulated the larvae absorption capacity for 1.0 kDa peptides at 16 DAH, which may have contributed for enhanced growth in later stages. The PartH diet stimulated the transcription of tryp1c and pept1 at 28 DAH, which seemed to reflect on increased post-larvae capacity to retain dietary 7.2 kDa polypeptides. That may indicate a possible strategy to optimize the digestion and utilisation of the PartH dietary protein, though it did not reflect into increased growth. The Intact diet promoted the transcription of pepsinogenA, which may reflect a reduced gastrointestinal transit time, which could have enhanced the dietary nutrients assimilation, ultimately improving growth. The present results suggest that, whereas pre-metamorphic sole larvae utilize better dietary protein with a moderate degree of hydrolysis, post-metamorphic sole make a greater use of intact protein., This work was funded by Project EPISOLE (FCT) [PTDC/MAR/110547/2009], through project CCMAR/Multi/04326/2013 (Portugal) from FCT (Portugal), and by project MICALA — I&DT Co-Promoção I&DT Co-Promoção No. 13380 (Portugal, supported by POAlgarve 21, QREN and European Union). P. Canada was supported by FCT grant SFRH/BD/82149/2011. Sofia Engrola was supported by FCT investigator grant IF/00482/2014/CP1217/CT0005 funded by the European Social Fund, the Operational Programme Human Potential and the Foundation for Science and Technology of Portugal (FCT). The authors acknowledge the collaboration of Wilson Pinto and André Santos (SPAROS Lda.), the Aquagroup team, (CCMAR) and Hernâni Gerós for revising the manuscript.

Microalgal biomasses are known to play a major role in fish pigmentation, which is particularly important in farmed fish, since colour and external appearance are the first cue for customers when choosing seafood. A study was undertaken to assess the potential of microalgae biomass from the diatom Phaeodactylum tricornutum as a functional ingredient for gilthead seabream (Sparus aurata) feeds. Three experimental diets were designed: a control diet (CTRL), this same diet supplemented with 2.5% of P. tricornutum wild strain (diet MA20); and a third diet with 2.5% of P. tricornutum biomass (diet MA37) cultivated under different temperature and light regimes that resulted in higher levels of fucoxanthin. Microalgae diets led to a reduction (P < 0.05 in MA37) of whole-body fat and lower lipid retention (P < 0.05 in MA20 and MA37). Microalgae did not impact odour, flavour, whiteness, and fatness perception in cooked fillets. Overall, colour analysis showed that P. tricornutum biomass led to significant differences compared to control in specific areas: the MA37 diet induced a significantly (P < 0.05) lighter and more vivid yellow colouration of seabream operculum (Delta E* approximate to 5) perceptible to the human eye; ventral skin lightness was also affected by the dietary treatments (P = 0.040), being higher for microalgae-fed groups, though this difference was not perceptually strong (Delta E* approximate to 1.7). Phaeodactylum tricornutum biomass can be used as a functional ingredient, improving external pigmentation and thus contributing to meet consumer expectations in relation to farmed gilthead seabream. EU FP7 [266401] FCT/MCTES (Portugal) through grant [SFRH/BD/73452/2010] info:eu-repo/semantics/publishedVersion

International audience; AbstractBackgroundIn breeding programs for aquaculture species, breeding goal traits are often weighted based on the desired gains but economic gain would be higher if economic values were used instead. The objectives of this study were: (1) to develop a bio-economic model to derive economic values for aquaculture species, (2) to apply the model to determine the economic importance and economic values of traits in a case-study on gilthead seabream, and (3) to validate the model by comparison with a profit equation for a simplified production system.MethodsA bio-economic model was developed to simulate a grow-out farm for gilthead seabream, and then used to simulate gross margin at the current levels of the traits and after one genetic standard deviation change in each trait with the other traits remaining unchanged. Economic values were derived for the traits included in the breeding goal: thermal growth coefficient (TGC), thermal feed intake coefficient (TFC), mortality rate (M), and standard deviation of harvest weight (σHW\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\sigma_{HW}$$\end{document}). For a simplified production system, improvement in TGC was assumed to affect harvest weight instead of growing period. Using the bio-economic model and a profit equation, economic values were derived for harvest weight, cumulative feed intake at harvest, and overall survival.ResultsChanges in gross margin showed that the order of economic importance of the traits was: TGC, TFC, M, and σHW\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\sigma_{HW}$$\end{document}. Economic values in € (kg production)−1 (trait unit)−1 were: 0.40 for TGC, −0.45 for TFC, −7.7 for M, and −0.0011 to −0.0010 for σHW\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\sigma_{HW}$$\end{document}. For the simplified production system, similar economic values were obtained with the bio-economic model and the profit equation. The advantage of the profit equation is its simplicity, while that of the bio-economic model is that it can be applied to any aquaculture species, because it can include any limiting factor and/or environmental condition that affects production.ConclusionsWe confirmed the validity of the bio-economic model. TGC is the most important trait to improve, followed by TFC and M, and the effect of σHW\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\sigma_{HW}$$\end{document} on gross margin is small.

Made available in DSpace on 2018-11-26T17:15:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Clarias gariepinus is a facultative air-breathing catfish that exhibits changes in heart rate (f(H)) associated with air breaths (AB). A transient bradycardia prior to the AB is followed by sustained tachycardia during breath-hold. This study evaluated air-breathing and cardiac responses to sustained aerobic exercise in juveniles (total length similar to 20 cm), and how exercise influenced variations in f(H) associated with AB. In particular, it investigated the role of adrenergic and cholinergic control in cardiac responses, and effects of pharmacological abolition of this control on air-breathing responses. Sustained exercise at 15, 30 and 45 cm s(-1) in a swim tunnel caused significant increases in f(AB) and f(H), from approximately 5 breaths h(-1) and 60 heartbeats min(-1) at the lowest speed, to over 60 breaths h(-1) and 100 beats min(-1) at the highest, respectively. There was a progressive decline in the degree of variation in f(H), around each AB, as f(AB) increased with exercise intensity. Total autonomic blockade abolished all variation in fH during exercise, and around each AB, but f(AB) responses were the same as in untreated animals. Cardiac responses were exclusively due to modulation of inhibitory cholinergic tone, which varied from >100% at the lowest speed to

Although molecular ecology of macroparasites is still in its infancy, general patterns are beginning to emerge, e.g. that the most vagile host in a complex life cycle is the main determinant of the population genetic structure of their parasites. This insight stems from the observation that populations of parasites with only freshwater hosts are more structured than those with terrestrial or airborne hosts. Until now, the same has not been tested for marine systems, where, in theory, a fully marine life cycle might sustain high dispersal rates because of the absence of obvious physical barriers in the sea. Here, we tested whether a marine trematode parasite that utilises migratory birds exhibited weaker population genetic structure than those whose life cycle utilises marine fish as the vagile host. Part of the mitochondrial cytochrome c oxidase 1 (COI) gene was sequenced from individual sporocysts from populations along the Atlantic coast of Europe and North Africa. Strong population structure (Φst = 0.25, p < 0.0001) was found in the fully marine trematode Bucephalus minimus (hosted by fish), while no significant structure (Φst = 0.015, p = 0.19257) was detected in Gymnophallus choledochus (hosted by birds). However, demographic models indicate recent colonisation rather than high dispersal as an alternative explanation of the low levels of structure observed in G. choledochus. Our study is the first to identify significant genetic population structure in a marine autogenic parasite, suggesting that connectivity between populations of marine parasites can be limited despite the general potential for high dispersal of their hosts in the marine environment.

EC is a Ramón y Cajal researcher fellow from the “Ministerio de Ciencia e Innovaci” (MICINN). This work was supported by funds from the MICINN (AGL2009-12427 and AGL2010-17324), the Catalonian Government (2009SGR-00402) and the “Xarxa de Referència d’R+D+I en Aqüicultura” and the European Union through the project LIFECYCLE (FP7-222719). Calpains are non-lysosomal calcium-activated neutral proteases involved in a wide range of cellular processes including muscle proteolysis linked to post-mortem flesh softening. The aims of this study were (a) to characterise several members of the calpain system in gilthead sea bream and (b) to examine their expression in relation to nutritional status and muscle tenderisation. We identified the complete open reading frame of gilthead sea bream calpains1-3, sacapn1, sacapn2, sacapn3, and two paralogs of the calpain small subunit1, sacapns1a and sacapns1b. Proteins showed 63-90% sequence identity compared with sequences from mammals and other teleost fishes, and the characteristic domain structure of vertebrate calpains. Transcripts of sacapn1, sacapn2, sacapns1a and sacapns1b had a wide tissue distribution, whereas sacapn3 was almost exclusively detected in skeletal muscle. Next, we assessed transcript expression in skeletal muscle following alteration of nutritional status by (a) fasting and re-feeding or (b) feeding four experimental diets with different carbohydrate-to-protein ratios. Fasting significantly reduced plasma glucose and increased free fatty acids and triglycerides, together with a significant increase in sacapns1b expression. Following 7 days of re-feeding, plasma parameters returned to fed values and sacapn1, sacapn2, sacapns1a and sacapns1b expression was significantly reduced. Furthermore, an increase in dietary carbohydrate content (11 to 39%) diminished growth but increased muscle texture, which showed a significant correlation with decreased sacapn1 and sacapns1a expression, whilst the other calpains remained unaffected. This study has demonstrated that calpain expression is modulated by nutritional status and diet composition in gilthead sea bream, and that the expression of several calpain members is correlated with muscle texture, indicating their potential use as molecular markers for flesh quality in aquaculture production. Publisher PDF

The presence of skeletal anomalies in farmed teleost fish is currently a major problem in aquaculture, entailing economical, biological and ethical issues. The common occurrence of skeletal abnormalities in farmed fish and the absence of effective solutions for avoiding their onset or definitely culling out the affected individuals as early as possible from the productive cycle, highlight the need to improve our knowledge on the basic processes regulating fish skeletogenesis and skeletal tissues differentiation, modelling and remodelling. Severe skeletal anomalies may actually occur throughout the entire life cycle of fish, but their development often begins with slight aberrations of the internal elements. Comprehensive investigation efforts conducted on reared larvae and juveniles could provide a great contribution in filling the gap in knowledge, as skeletogenesis and skeletal tissue differentiation occur during these early life stages. The aim of this review is to provide a synthetic but comprehensive picture of the actual knowledge on the ontogeny, typologies and occurrence of skeletal anomalies, and on the proposed causative factors for their onset in larvae and juveniles of European farmed fish. The state-of-art of knowledge of these issues is analysed critically intending to individualize the main gaps of knowledge that require to be filled, in order to optimize the morphological quality of farmed juveniles. LARVANET COST action [FA0801]; Italian Ministry for Agriculture, Food and Forestry Policy [5C49, 6C82, 6C100, 6C138, 6C144]; Commission of the European Communities [SSP-2005-44483]; NSRF of the Ministry of Education, Lifelong Learning and Religious Affairs, Greece [09SYN-24-619]; Portuguese Foundation for Science and Technology - FCT [PDTC-MAR-105152-2008]; integrated action CRUP-MICINN [AI-E-54]; European Community [222719-LIFECYCLE]; Spanish Ministry of Science and Innovation (MICIIN) [AGL2008-03897-C04-01, AIB2010-PT-00313] info:eu-repo/semantics/publishedVersion

Previous experiments with Senegalese sole (Solea senegalensis) have demonstrated that dietary lipid levels above 8% impaired growth and did not promote protein retention. We hypothesised that this low ability to use high-lipid diets may depend on the dietary protein level. In the present study, a 2 x 2 factorial design was applied where two dietary lipid (4-17% DM) and two dietary protein (below and above the requirement levels, 48 and 54% DM) levels were tested in juveniles for 114 d. Growth performance was not improved by the increase in dietary fat, irrespectively of the dietary protein levels. Protein retention was similar among the diets, although fish fed the diets with high lipid content resulted in significantly lower protein gain. Among the enzymes involved in amino acid catabolism, only aspartate aminotransferase activity in the liver was affected by the dietary lipid levels, being stimulated in fish fed high-lipid diets. Moreover, phosphofructokinase 1 activity was significantly elevated in the muscle of Senegalese sole fed 4% lipid diets, suggesting enhanced glycolysis in the muscle when the dietary lipid supply was limited and dietary starch increased. The results confirmed that high-lipid diets do not enhance growth, and data from the selected enzymes support the assumption that lipids are not efficiently used for energy production and protein sparing, even when dietary protein is below the protein requirement of the species. Furthermore, data suggest a significant role of glucose as the energy source in Senegalese sole. Fundacao para a Ciencia e Tecnologia of Portugal [SFRH/BD/47,780/2008] info:eu-repo/semantics/publishedVersion

It has been hypothesised that, at non-limiting water oxygen conditions, voluntary feed intake (FI) in fish is limited by the maximal physiological capacity of oxygen use (i.e. an ‘oxystatic control of FI in fish’). This implies that fish will adjust FI when fed diets differing in oxygen demand, resulting in identical oxygen consumption. Therefore, FI, digestible energy (DE) intake, energy balance and oxygen consumption were monitored at non-limiting water oxygen conditions in Nile tilapia fed diets with contrasting macronutrient composition. Diets were formulated in a 2 × 2 factorial design in order to create contrasts in oxygen demand: two ratios of digestible protein (DP):DE (‘high’v.‘low’); and a contrast in the type of non-protein energy source (‘starch’v.‘fat’). Triplicate groups of tilapia were fed each diet twice daily to satiation for 48 d. FI (g DM/kg0·8per d) was significantly lower (9·5 %) in tilapia fed the starch diets relative to the fat diets. The DP:DE ratio affected DE intakes (P R20·81,P

The effect of the type of non-protein energy (NPE) on energy utilisation in Nile tilapia was studied, focusing on digestible energy utilisation for growth (kgDE). Furthermore, literature data on kgDE across fish species were analysed in order to evaluate the effect of dietary macronutrient composition. A total of twelve groups of fish were assigned in a 2 × 2 factorial design: two diets (‘fat’ v. ‘starch’) and two feeding levels (‘low’ v. ‘high’). In the ‘fat’-diet, 125 g fish oil and in the ‘starch’-diet 300 g maize starch were added to 875 g of an identical basal mixture. Fish were fed restrictively one of two ration levels (‘low’ or ‘high’) for estimating kgDE. Nutrient digestibility, N and energy balances were measured. For estimating kgDE, data of the present study were combined with previous data of Nile tilapia fed similar diets to satiation. The type of NPE affected kgDE (0·561 and 0·663 with the ‘starch’ and ‘fat’-diets, respectively; P kgDE range from 0·31 to 0·82. Variability in kgDE was related to dietary macronutrient composition, the trophic level of the fish species and the composition of growth (fat:protein gain ratio). The across-species comparison suggested that the relationships of kgDE with trophic level and with growth composition were predominantly induced by dietary macronutrient composition. Reported kgDE values increased linearly with increasing dietary fat content and decreasing dietary carbohydrate content. In contrast, kgDE related curvilinearly to dietary crude protein content. In conclusion, energy utilisation for growth is influenced by dietary macronutrient composition.