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Sadasivam Kaushik - One of the best experts on this subject based on the ideXlab platform.
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dietary arginine degradation is a major pathway in ureagenesis in juvenile Turbot psetta maxima
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2002Co-Authors: M F Gouilloucoustans, V Fournier, Robert Metailler, C Vachot, E Desbruyeres, Christine Huelvan, J Moriceau, Le H Delliou, Sadasivam KaushikAbstract:Recent studies indicate that urea excretion is responsive to protein intake and that Turbot, Psetta maxima, appear to differ from other species by their urea excretion pattern and levels. This study was undertaken to evaluate the influence of dietary nitrogen and arginine on ureagenesis and excretion in Turbot. Juvenile Turbot (29 g) were fed semi-purified diets containing graded levels of nitrogen (0–8% dry matter) and arginine (0–3% dry matter) for 6 weeks. Growth data showed that Turbot have high dietary nitrogen (123 mg/kg metabolic body weight/day) and very low dietary arginine (9.3 mg/kg metabolic body weight/day) requirements for maintenance. Requirements for unit body protein accretion were 0.31 g and 0.15 g for nitrogen and arginine respectively. Post-prandial plasma urea levels and urea excretion rates showed that urea production was significantly (P<0.05) influenced by dietary arginine levels. While hepatic arginase (EC 3.5.3.1) activity increased significantly (P<0.05) with increasing dietary arginine levels, activities of other enzymes of the ornithine urea cycle were very low. Our data strongly suggest that the ornithine urea cycle is not active in the Turbot liver and that dietary arginine degradation is a major pathway of ureagenesis in Turbot.
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digestibility of extruded peas extruded lupin and rapeseed meal in rainbow trout oncorhynchus mykiss and Turbot psetta maxima
Aquaculture, 2000Co-Authors: Christine Burel, Thierry Boujard, Francesca Tulli, Sadasivam KaushikAbstract:Apparent digestibility coefficients (ADC) of nutrients and energy of extruded peas, extruded lupin and rapeseed meals were determined in juvenile rainbow trout and Turbot. Extruded lupin was found to be a promising substitute for fish meal in the diets of trout and Turbot, with an acceptable digestibility of its dry matter (70% in trout and 81% in Turbot) and a high digestibility of its protein (96% in trout and 98% in Turbot) and its energy (77% in trout and 85% in Turbot). Extruded peas had a lower digestibility of its protein in trout (88%) than in Turbot (92%), and the ADC of energy, mainly supplied as starch, was relatively low (69% in trout and 78% in Turbot). The digestibility of rapeseed meal was improved by a thermal treatment. Without thermal treatment, rapeseed meal had a low digestibility of its dry matter (57%) and energy (69%) in Turbot. The availability of phosphorus was higher for extruded lupin (62% in trout and 100% in Turbot) compared to the other plant-ingredients. When compared to a solvent-extracted meal, the availability of phosphorus from rapeseed meal was improved by heat treatment in both species (42% vs. 26% in trout and 65% vs. 49% in Turbot).
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partial or total replacement of fish meal by corn gluten meal in diet for Turbot psetta maxima
Aquaculture, 1999Co-Authors: Christelle Regost, J Arzel, Sadasivam KaushikAbstract:The effect of corn gluten meal (CGM) as a partial or total replacement of fish meal was studied in Turbot (Psetta maxima). Five experimental diets containing a gradient of CGM were fed to triplicate groups of Turbot (initial body weight of 65 g) over 9 weeks at 17°C. Turbot fed a diet containing 20% of CGM had comparable growth performances as these fed a fishmeal based diet. Total replacement of fish meal adversely affected growth. Digestibility of nutrients and energy of the diets decreased with the increase in levels of dietary corn gluten meal. Supplementation of arginine and lysine in diets containing CGM induced an improvement of the availability of these two amino acids. The incorporation of CGM in diets significantly affected plasma cholesterol and triglyceride concentrations while no effect was observed on plasma levels of thyroid hormones. These results suggest that protein from CGM can replace one third of fish meal protein in the diets for Turbot.
Li Sun - One of the best experts on this subject based on the ideXlab platform.
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Transcriptome analysis reveals temperature-regulated antiviral response in Turbot Scophthalmus maximus.
Fish & shellfish immunology, 2017Co-Authors: Jian Zhang, Li SunAbstract:Megalocytivirus is a severe pathogen to Turbot (Scophthalmus maximus), a popular aquaculture species in many countries. In this study, we investigated the effect of temperature on the antiviral response of Turbot at transcriptome level. We found that when Turbot were infected with megalocytivirus RBIV-C1 at low temperatures (14 °C, 16 °C, and 18 °C), viral replication was undetectable or moderate and no fish mortality occurred; in contrast, when Turbot were infected with RBIV-C1 at high temperatures (20 °C, 22 °C, and 24 °C), viral replication was robust and 100% host mortality was observed. During the course of viral infection, downward temperature shift curbed viral replication and augmented host survival, whereas upward temperature shift promoted viral replication and reduced host survival. Comparative transcriptome analyses were conducted to examine the whole-genome transcription of Turbot infected with RBIV-C1 at 16 °C and 22 °C for 4 days (samples S16-4d and S22-4d, respectively) and 8 days (samples S16-8d and S22-8d, respectively). The results showed that compared to S22-4d and S22-8d, 1600 and 5927 upregulated unigenes of various functional categories were identified in S16-4d and S16-8d, respectively. Of these genes, 22 were immune-related, most of which were detected in S16-8d and exhibited more genetic subtypes in S16-8d than in S16-4d. In addition, upregulated genes associated with cell junctions and cell membrane were also identified. These results indicate that temperature had a profound effect on the global transcription of Turbot, which consequently affects the immune as well as physical resistance of the fish against viral infection.
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neutrophils of scophthalmus maximus produce extracellular traps that capture bacteria and inhibit bacterial infection
Developmental and Comparative Immunology, 2016Co-Authors: Heng Chi, Li SunAbstract:Neutrophils constitute an essential part of the innate immune system. Recently, neutrophils have been found to produce a complex extracellular structure called neutrophil extracellular traps (NETs) that capture bacteria, fungi, and parasites. In fish, a few studies on NETs production have been reported, however, the function of fish NETs is unknown. In this study, we examined the ability of Turbot (Scophthalmus maximus) neutrophils to produce NETs and investigated the effect of Turbot NETs on bacterial infection. We found that upon lipopolysaccharides treatment, Turbot head kidney neutrophils produced typical NETs structures that contained DNA and histones. Bacteria treatment also induced production of NETs, which in turn entrapped the bacterial cells and inhibited bacterial replication. Furthermore, when introduced into Turbot, NETs-trapped bacteria exhibited significantly weakened ability of tissue dissemination and colonization. These results indicate for the first time that teleost NETs possess apparent antibacterial effect both in vitro and in vivo.
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selection of normalization factors for quantitative real time rt pcr studies in japanese flounder paralichthys olivaceus and Turbot scophthalmus maximus under conditions of viral infection
Veterinary Immunology and Immunopathology, 2013Co-Authors: Jian Zhang, Boguang Sun, Zhizhong Xiao, Li SunAbstract:Disease outbreaks caused by iridoviruses are known to affect farmed flounder (Paralichthys olivaceus) and Turbot (Scophthalmus maximus). To facilitate quantitative real time RT-PCR (qRT-PCR) analysis of gene expression in flounder and Turbot during viral infection, we in this study examined the potentials of 9 housekeeping genes of flounder and Turbot as internal references for qRT-PCR under conditions of experimental infection with megalocytivirus, a member of the Iridoviridae family. The mRNA levels of the 9 housekeeping genes in the brain, gill, heart, intestine, kidney, liver, muscle, and spleen of flounder and Turbot were determined by qRT-PCR at 24h and 72h post-viral infection, and the expression stabilities of the genes were determined with geNorm and NormFinder algorithms. The results showed that (i) viral infection induced significant changes in the mRNA levels of the all the examined genes in a manner that was dependent on both tissue type and infection stage; (ii) for a given time point of infection, stability predictions made by the two algorisms were highly consistent for most tissues; (iii) the optimum reference genes differed at different infection time points at least in some tissues; (iv) at both examined time points, no common reference genes were identified across all tissue types. These results indicate that when studying gene expression in flounder and Turbot in relation to viral infection, different internal references may have to be used not only for different tissues but also for different infection stages.
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identification and analysis of a cpg motif that protects Turbot scophthalmus maximus against bacterial challenge and enhances vaccine induced specific immunity
Vaccine, 2010Co-Authors: Chunsheng Liu, Yun Sun, Li SunAbstract:Oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs in certain contexts are known to be immunostimulatory in vertebrate systems. CpG ODNs with immune effects have been identified for many fish species but, to our knowledge, not for Turbot. In this study, a Turbot-effective CpG ODN, ODN 205, was identified and a plasmid, pCN5, was constructed which contains the CpG motif of ODN 205. When administered into Turbot via intraperitoneal (i.p.) injection, both ODN 205 and pCN5 could (i) inhibit bacterial dissemination in blood in dose and time dependent manners, and (ii) protect against lethal bacterial challenge. Immunological analyses showed that in vitro treatment with ODN 205 stimulated peripheral blood leukocyte proliferation, while i.p. injection with ODN 205 enhanced the respiratory burst activity, chemiluminescence response, and acid phosphatase activity of Turbot head kidney macrophages. pCN5 treatment-induced immune responses similar to those induced by ODN 205 treatment except that pCN5 could also enhance serum bactericidal activity in a calcium-independent manner. To examine whether ODN 205 and pCN5 had any effect on specific immunity, ODN 205 and pCN5 were co-administered into Turbot with a Vibrio harveyi subunit vaccine, DegQ. The results showed that pCN5, but not ODN 205, significantly increased the immunoprotective efficacy of DegQ and enhanced the production of specific serum antibodies in the vaccinated fish. Further analysis indicated that vaccination with DegQ in the presence of pCN5 upregulated the expression of the genes encoding MHC class II alpha, IgM, Mx, and IL-8 receptor. Taken together, these results demonstrate that ODN 205 and pCN5 can stimulate the immune system of Turbot and induce protection against bacterial challenge. In addition, pCN5 also possesses adjuvant property and can potentiate vaccine-induced specific immunity. (C) 2010 Elsevier Ltd. All rights reserved.
Paula S Haynes - One of the best experts on this subject based on the ideXlab platform.
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the early life history of Turbot psetta maxima l on nursery grounds along the west coast of ireland 2007 2009 as described by otolith microstructure
Fisheries Research, 2011Co-Authors: Paula S Haynes, Deirdre Brophy, David McgrathAbstract:Abstract The early life history of Turbot ( Psetta maxima Linnaeus) was investigated over a three year period (2007–2009). 0-group Turbot were collected in September of each year, from three nursery areas along the Irish west coast. The timing of hatching and settlement and the duration of the larval stage were estimated using otolith microstructure analysis. Otolith increment widths were used to derive an index of relative growth rates before and after settlement. Turbot were estimated to have hatched between May and June and settled onto nursery grounds between June and July over the 3 years of the study. No inter-annual differences in the timing of hatching or settlement were observed. Spatial variability was detected, with Turbot collected from one location hatching and settling significantly earlier compared to other locations. Turbot from the same location also displayed higher post-settlement otolith growth rates suggesting that this may be a nursery of high habitat quality. Turbot captured in 2009 exhibited significantly shorter larval durations and higher larval otolith growth rates compared to Turbot collected in other years. Post-settlement growth rates displayed the opposite trend, with Turbot showing lower post-settlement growth in 2009. The results provide valuable baseline data on critical events in the early life history of a data-poor species.
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annual and spatial variation in the abundance length and condition of juvenile Turbot psetta maxima l on nursery grounds on the west coast of ireland 2000 2007
Journal of Sea Research, 2010Co-Authors: Paula S Haynes, Deirdre Brophy, David Mcgrath, Roisin Ocallaghan, Stephen Comerford, Paul CasburnAbstract:Abstract Turbot ( Psetta maxima Linnaeus) is a high value commercially exploited marine flatfish which occurs in European waters, from the Northeast Atlantic to the Arctic Circle, the Baltic and Mediterranean Sea. In Ireland, Turbot are the most valuable commercial non-quota species. Very little is known about their population dynamics in the wild, in particular during the sandy beach nursery phase of the life history. In 2000, a survey was established to assess flatfish species on nursery grounds on the west coast of Ireland. Eleven sandy beaches were assessed for 0+ Turbot by beach seining, over an eight year period (2000–2007) during the months of August and September. The objective of the study was to estimate juvenile Turbot abundance and size structure to determine if any spatial and annual trends existed. Large scale variability in the recruitment of fish to nursery grounds may be indicative of fluctuations in the adult stock. Turbot were found to recruit to five beaches consistently over the eight year period. Temporal and spatial variability in the relative abundance and length of Turbot was discerned, with no apparent overall trend. However, certain nursery grounds were shown in most of the years examined to support higher abundances of Turbot in comparison to other areas over the eight year period. Turbot abundances on nursery grounds were significantly correlated with mean spring sea temperatures during the pelagic stage. The condition of Turbot did not significantly differ on an annual or spatial scale. Mean densities of 0+ Turbot along the Irish coast were found to be similar and at times higher than other areas in Europe, ranging from 0.1 (± 0.3) individuals 1000 m − 2 to 18.5 (± 6.9) individuals 1000 m − 2 . Mean Turbot total length on beaches ranged from 3.8 cm (± 0.6) to 6.6 cm (± 4.3). The observed spatial and temporal variability in abundance and length highlights the need for long-term studies when assessing juvenile flatfish populations. Results from the present study have provided much needed baseline data on wild juvenile Turbot populations which is severely lacking for this species both on an Irish and on a European scale.
David Mcgrath - One of the best experts on this subject based on the ideXlab platform.
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the early life history of Turbot psetta maxima l on nursery grounds along the west coast of ireland 2007 2009 as described by otolith microstructure
Fisheries Research, 2011Co-Authors: Paula S Haynes, Deirdre Brophy, David McgrathAbstract:Abstract The early life history of Turbot ( Psetta maxima Linnaeus) was investigated over a three year period (2007–2009). 0-group Turbot were collected in September of each year, from three nursery areas along the Irish west coast. The timing of hatching and settlement and the duration of the larval stage were estimated using otolith microstructure analysis. Otolith increment widths were used to derive an index of relative growth rates before and after settlement. Turbot were estimated to have hatched between May and June and settled onto nursery grounds between June and July over the 3 years of the study. No inter-annual differences in the timing of hatching or settlement were observed. Spatial variability was detected, with Turbot collected from one location hatching and settling significantly earlier compared to other locations. Turbot from the same location also displayed higher post-settlement otolith growth rates suggesting that this may be a nursery of high habitat quality. Turbot captured in 2009 exhibited significantly shorter larval durations and higher larval otolith growth rates compared to Turbot collected in other years. Post-settlement growth rates displayed the opposite trend, with Turbot showing lower post-settlement growth in 2009. The results provide valuable baseline data on critical events in the early life history of a data-poor species.
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annual and spatial variation in the abundance length and condition of juvenile Turbot psetta maxima l on nursery grounds on the west coast of ireland 2000 2007
Journal of Sea Research, 2010Co-Authors: Paula S Haynes, Deirdre Brophy, David Mcgrath, Roisin Ocallaghan, Stephen Comerford, Paul CasburnAbstract:Abstract Turbot ( Psetta maxima Linnaeus) is a high value commercially exploited marine flatfish which occurs in European waters, from the Northeast Atlantic to the Arctic Circle, the Baltic and Mediterranean Sea. In Ireland, Turbot are the most valuable commercial non-quota species. Very little is known about their population dynamics in the wild, in particular during the sandy beach nursery phase of the life history. In 2000, a survey was established to assess flatfish species on nursery grounds on the west coast of Ireland. Eleven sandy beaches were assessed for 0+ Turbot by beach seining, over an eight year period (2000–2007) during the months of August and September. The objective of the study was to estimate juvenile Turbot abundance and size structure to determine if any spatial and annual trends existed. Large scale variability in the recruitment of fish to nursery grounds may be indicative of fluctuations in the adult stock. Turbot were found to recruit to five beaches consistently over the eight year period. Temporal and spatial variability in the relative abundance and length of Turbot was discerned, with no apparent overall trend. However, certain nursery grounds were shown in most of the years examined to support higher abundances of Turbot in comparison to other areas over the eight year period. Turbot abundances on nursery grounds were significantly correlated with mean spring sea temperatures during the pelagic stage. The condition of Turbot did not significantly differ on an annual or spatial scale. Mean densities of 0+ Turbot along the Irish coast were found to be similar and at times higher than other areas in Europe, ranging from 0.1 (± 0.3) individuals 1000 m − 2 to 18.5 (± 6.9) individuals 1000 m − 2 . Mean Turbot total length on beaches ranged from 3.8 cm (± 0.6) to 6.6 cm (± 4.3). The observed spatial and temporal variability in abundance and length highlights the need for long-term studies when assessing juvenile flatfish populations. Results from the present study have provided much needed baseline data on wild juvenile Turbot populations which is severely lacking for this species both on an Irish and on a European scale.
Carsten Schulz - One of the best experts on this subject based on the ideXlab platform.
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the effect of high ortho phosphate water levels on growth feed intake nutrient utilization and health status of juvenile Turbot psetta maxima reared in intensive recirculating aquaculture systems ras
Aquacultural Engineering, 2013Co-Authors: Chris G.j. Van Bussel, J.p. Schroeder, Lars Mahlmann, Saskia Kroeckel, Carsten SchulzAbstract:In intensive recirculating aquaculture systems (RAS) ortho-phosphate (ortho-P) is one of the main accumulating substances, but effects of chronically elevated concentrations on fish health and production performance are still unknown. Therefore 120 juvenile Turbot (Psetta maxima) were exposed to ortho-P concentrations of 3 mg/L (control - C), 26 mg/L (low - LP), 52 mg/L (medium - MP) and 82 mg/L (high HP) for 56 days and fed until satiation with a commercial diet. Health status and feed conversion ratio (FCR) were not significantly affected by treatment (p > 0.05). Specific growth rates (SGR) and daily feed intake (DFI) of C were not considered significantly different from LP, MP and HP treatments, however LP showed significant higher DFI and SGR than HP (p 0.05) a potential aqueous P uptake might result in metabolic benefits leading to the observed growth enhancement in the LP treatment. In a second experiment 114 juvenile Turbot were exposed to ortho-P concentrations of 2 mg/L (C2) and 25 mg/L (LP2) for 63 days and fed until satiation with a low P diet (4.6 g digestible-P/kg diet). Overall production performance was low due to low voluntary feed intake. Whereas the FCR was unaffected by treatment (p > 0.05), significantly higher feed intake and biomass gain were observed for LP2 compared to C2 (p 0.05). In conclusion the accumulation of ortho-P in RAS does not negatively affect health of Turbot. Elevated ortho-P seems to have slight positive effects on production performance of juvenile Turbot. Further research to quantify dietary P requirements for Turbot in general, as well as for Turbot raised under elevated ortho-P conditions in RAS is strongly required. (C) 2013 Elsevier B.V. All rights reserved.
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energy requirement for maintenance and efficiency of energy utilization for growth in juvenile Turbot psetta maxima l the effect of strain and replacement of dietary fish meal by wheat gluten
Aquaculture, 2012Co-Authors: Carsten Dietz, Saskia Kroeckel, Carsten Schulz, Andreas SusenbethAbstract:Restricted ration level experiments were realized to determine the gross, digestible and metabilizable energy requirements for maintenance (GEm; DEm; MEm) and the efficiencies of energy utilization for growth (kg(GE); kg(DE); kg(ME)) in juvenile Turbot. The effects of the fish strain (Denmark, DK; Iceland, IS) as well as the partial replacement of fish meal by wheat gluten in the diet were examined as possible factors affecting the energy metabolism. Turbot (initial body weight 49 g) were reared in a recirculation aquaculture system supplied with seawater at a temperature of 17 ± 0.6 °C and 26 ± 1.2 ppt salinity for 67 days. Two diets, differing in wheat gluten content (80 g or 330 g kg− 1 diet) were fed at six increasing feeding levels, from near maintenance to ad libitum levels, once a day per hand. Chemical composition and energy content of body weight gain were determined by using the comparative slaughter technique. Linear regression analyses were applied to obtain GEm, DEm, MEm, kg(GE), kg(DE) and kg(ME).GEm, DEm and MEm were 21.6–29.8, 17.0–23.5 and 15.5–21.4 kJ kg− 0.8 d− 1, respectively, and kg(GE), kg(DE) and kg(ME) were 0.46–0.49, 0.59–0.64 and 0.63–0.68, respectively. Values for GEm, DEm and MEm as well as for kg(GE), kg(DE) and kg(ME) in Turbot from IS were significantly higher than in fish from DK, but without any effect on energy retention at high feeding levels. Turbot receiving the diet where fish meal was partially replaced by wheat gluten showed higher GEm, DEm and MEm as well. No effect on energy retention at high feeding levels was observed again. It is concluded that differences in energy metabolism between strains might be considered when selecting Turbot for aquaculture production. Energy requirement for maintenance and efficiency of energy utilization for growth in juvenile Turbot (Psetta maxima, L.): The effect of strain and replacement of dietary fish meal by wheat gluten. Available from: https://www.researchgate.net/publication/256917001_Energy_requirement_for_maintenance_and_efficiency_of_energy_utilization_for_growth_in_juvenile_Turbot_Psetta_maxima_L_The_effect_of_strain_and_replacement_of_dietary_fish_meal_by_wheat_gluten [accessed Apr 3, 2017].
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The chronic effect of nitrate on production performance and health status of juvenile Turbot (Psetta maxima)
Aquaculture, 2012Co-Authors: Chris G.j. Van Bussel, J.p. Schroeder, Sven Wuertz, Carsten SchulzAbstract:The chronic effect of nitrate on the production performance and health of marine cultured fish species is still unknown. Thus, the aim of the present research was to evaluate the chronic effect of nitrate on production parameters and health status of Turbot (Psetta maxima). Juvenile Turbot were exposed to 0 mg/L NO3-N (control C), 125 mg/L NO3-N (low nitrate LN), 250 mg/L NO3-N (medium nitrate MN) and 500 mg/L NO3-N (high nitrate HN) for 6 weeks in small-scaled recirculating aquaculture systems (RAS). After 42 d, biomass yield, length, weight and specific growth rate (SGR) were significantly (p 0.05) between C and LN but were significantly (p 0.05) between treatments. Thus, nitrate negatively influences the production performance of Turbot, even at low concentrations and nitrate management is therefore a key-factor in Turbot RAS production. (C) 2011 Elsevier B.V. All rights reserved.
