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European Sea Bass (european + sea_bass)
Terms modified by European Sea Bass Selected AbstractsSensory, chemical and microbiological assessment of farm-raised European sea bass (Dicentrarchus labrax) stored in melting iceINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2002Vasiliki R. Kyrana Farm raised European sea bass (Dicentrarchus labrax) were stored in melting ice for a period up to 22 days from the time of harvest, and sensory, chemical, and microbiological assessments were made at intervals. The storage life of the ungutted fish, determined by sensory evaluation of the cooked flesh, was 19 days. Of the chemical tests, only k1 value provided a useful means of monitoring early storage change. Trimethylamine, total volatile bases and pH showed practically no change during the first half of the edible storage life of the fish. Changes in free fatty acid (FFA) content and thiobarbituric acid (TBA) value could not be used to determine loss of acceptability or end of storage life. Sulphide producing bacteria constituted a very low proportion of the total aerobic flora, suggesting that the common sulphide producer Shewanella putrefaciens was not a major spoiler of sea bass in this trial. [source] Double staining protocol for developing European sea bass (Dicentrarchus labrax) larvaeJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2010M. J. Darias Summary The alcian blue-alizarin red technique was successfully adjusted to stain developing European sea bass (Dicentrarchus labrax) larvae. For an optimal staining protocol design both larval size and their morphological characteristics at each developmental stage were considered, since such parameters notably influence the staining of tissues. The incubation times of the different solutions were adjusted to allow the stain penetration for revealing the integrity of cartilaginous and bony tissues without significant tissue degradation. Three developmental windows were determined for an optimal staining procedure: (i) 4.5,6.4 mm, (ii) 6.7,8.7 mm, and (iii) 12.8,15.5 mm total length (TL). In order to validate the continuity of staining along the larval development, quantification of bone mineralization and osteocalcin gene expression were also monitored. Quantitative analysis revealed that ossification followed an exponential kinetic that was positively correlated with the osteocalcin gene expression pattern (Rs = 0.9762, P < 0.05). The mineralized tissue increased from 6.4 mm TL onwards, corresponding with the detection of the first ossified structures. The quantity of bony tissue increased gradually until 7.6 mm TL, since mineralization remained limited to the skull. From 8.3 to 15.5 mm TL, the mineralized bone was notable and nearly concerned the whole larval skeleton (skull, vertebral column and caudal complex). Since it was possible to detect the first cartilaginous and mineralized structures in specimens as small as 4.5 and 6.4 mm TL, respectively, this procedure is a useful tool to study the European sea bass skeletal ontogenesis, to precociously diagnose skeletal malformations in small larvae and eventually to better characterize the effect of different environmental and/or nutritional factors on the ossification status of specific skeletal components. [source] Effects of dietary l -tryptophan and lighting conditions on growth performance of European sea bass (Dicentrarchus labrax) juveniles reared in a recirculating water systemJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2005S. E. Papoutsoglou Summary The aim of the present study was to investigate possible stressful effects on European sea bass Dicentrarchus labrax reared under constant darkness (0L-24D) and to examine the possible anti-stressful effect of dietary tryptophan (TRP) supplementation. Juvenile European sea bass (initial body weight 4.23 ± 0.032 g) were reared for 10 weeks under 0L-24D and 12L-12D and fed either a commercial diet (0.47% TRP) or the same diet supplemented with L-TRP (2.47% TRP). Results showed that lighting conditions had no significant effect on fish growth, while a depressive effect by the TRP supplementation was obvious. All fish populations reared under 0L-24D exhibited reduced body protein, lipid and ash content and increased food consumption. Reduced body lipids, food consumption and nutrient utilization were observed in TRP-supplemented fed fish, along with lower liver lipids. Dietary TRP enrichment significantly lowered liver saturated and monounsaturated acids and increased poly- and highly-unsaturated fatty acids, especially in combination with 0L-24D. These changes were also considerably reflected in carcass fatty acid composition. [source] Development of a sensitive diagnostic assay for fish nervous necrosis virus based on RT-PCR plus nested PCRJOURNAL OF FISH DISEASES, Issue 5 2000L Dalla Valle A polymerase chain reaction (PCR)-based assay to detect nervous necrosis virus (NNV) in fish was developed by using two sets of primers designed on a highly conserved region of the coat protein gene encoded by RNA2 of NNV. The first pair of primers amplified a fragment of 605 bp by one-step reverse-transcription (RT)-PCR, while the second pair amplified an internal segment of 255 bp by nested PCR. Addition of nested PCR increased the assay sensitivity 100-fold when carried out in a separate tube (two-step assay) and 10-fold when performed in the same tube (one-step assay). The sensitivity of the two-step assay was 104 times higher than that of virus cultivation. Nested PCR served also to confirm the specificity of the first amplification, as verified also by Southern hybridization analysis and direct sequencing. In species known to be susceptible to infection, such as European sea bass, Dicentrarchus labrax, and gilthead seabream, Sparus aurata, NNV was often detectable in brain tissue by RT-PCR alone but only by the two-step assay in blood, sperm, ovarian tissue or larvae. The same was true for sperm and ovarian tissue of shi drum, Umbrina cirrosa. NNV was also detected in the brains of Japanese red seabream, Pagrus major and brown meagre, Sciaena umbra, suggesting that these species can also be infected. No NNV was detected in samples of Artemia salina nauplii and rotifers obtained from a fish farm with an NNV outbreak. The inclusion of nested PCR in the assay appears to be necessary to screen out NNV-positive broodfish by blood sampling and testing of their larval progeny. [source] In vitro proteolysis of myofibrillar and sarcoplasmic proteins of European sea bass (Dicentrarchus Labrax L) by an endogenous m-calpainJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2002Véronique Verrez-Bagnis Abstract The effects of m-calpain isolated from the skeletal muscle of sea bass on sarcoplasmic and myofibrillar proteins isolated from the same tissue were examined in vitro. Incubation of sarcoplasmic proteins with m-calpain resulted in only a slight decrease (0.7,kDa) in the molecular weight (MW) of a 26.5,kDa protein. Degradation of myofibrils, monitored by quantification of TCA-soluble peptides generated, resulted in the maximum amount of peptides being generated after 1,h of incubation at 25,°C. Noticeable modifications in the SDS-PAGE profile of digested myofibrils were observed, including partial denaturation of myosin heavy chain and the release of tropomyosin, ,69 and ,27,kDa doublet bands and a few polypeptides of MW lower than 20,kDa in the soluble fraction. Examination of the degradation patterns of myofibrillar proteins using Western blotting showed that ,-actinin was partially degraded, with release of native ,-actinin and its fragments from myofibrils, whereas desmin was highly degraded after 2,h of digestion. © 2002 Society of Chemical Industry [source] More polymorphic microsatellite markers in the European sea bass (Dicentrarchus labrax L.)MOLECULAR ECOLOGY RESOURCES, Issue 4 2002Y. Ciftci Abstract We provide details of five microsatellite loci screened in 163 individual sea bass. Large numbers of alleles were observed at three loci (20,25) and heterozygosities ranged from 0.52 to 0.86. These loci should prove useful for population genetic studies and for the pedigree analysis and genetic management of this species in aquaculture. [source] Effects of a natural parasitical infection (Lernanthropus kroyeri) on the immune system of European sea bass, Dicentrarchus labrax LPARASITE IMMUNOLOGY, Issue 12 2009M. A. HENRY Summary The immune response of European sea bass, Dicentrarchus labrax, to a natural infection by the copepod parasite Lernanthropus kroyeri was evaluated for the first time in vivo. The results clearly demonstrated the triggering of the fish immune system by the parasite. Lysozyme activity and alternative complement pathway were involved in the early action against the parasitical infection, whilst classical complement and respiratory burst (RB) activity took over in the later stages of infection. It was hypothesized that the levels of alternative and classical complement and RB stimulation indexes may determine the resistance capacity of the fish to the parasite. It is not clear how parasites can survive despite the strong immunological arsenal deployed by the fish. The continual increase of prevalence and severity of parasite infection suggested that the parasite's mechanism of evasion of the immune system was extremely successful. The contrasting decrease in the negative effects of parasites on the fish health (such as gills anaemia) suggested that an equilibrium between the parasites and their hosts was reached in chronic infection. These dynamic interactions between parasites and fish hosts were probably the main determinant of host specificity. [source] QTL for body weight, morphometric traits and stress response in European sea bass Dicentrarchus labraxANIMAL GENETICS, Issue 4 2010C. Massault Summary Natural mating and mass spawning in the European sea bass (Dicentrarchus labrax L., Moronidae, Teleostei) complicate genetic studies and the implementation of selective breeding schemes. We utilized a two-step experimental design for detecting QTL in mass-spawning species: 2122 offspring from natural mating between 57 parents (22 males, 34 females and one missing) phenotyped for body weight, eight morphometric traits and cortisol levels, had been previously assigned to parents based on genotypes of 31 DNA microsatellite markers. Five large full-sib families (five sires and two dams) were selected from the offspring (570 animals), which were genotyped with 67 additional markers. A new genetic map was compiled, specific to our population, but based on the previously published map. QTL mapping was performed with two methods: half-sib regression analysis (paternal and maternal) and variance component analysis accounting for all family relationships. Two significant QTL were found for body weight on linkage group 4 and 6, six significant QTL for morphometric traits on linkage groups 1B, 4, 6, 7, 15 and 23 and three suggestive QTL for stress response on linkage groups 3, 14 and 23. The QTL explained between 8% and 38% of phenotypic variance. The results are the first step towards identifying genes involved in economically important traits like body weight and stress response in European sea bass. [source] Evaluation of zinc supplementation in European sea bass (Dicentrarchus labrax) juvenile dietsAQUACULTURE RESEARCH, Issue 9 2010Eleni Fountoulaki Abstract This study aimed to investigate the effect of increased zinc dietary levels on the growth performance, feed utilization, immune status and induced wound healing in European sea bass (Dicentrarchus labrax). Fish weighing 10 g were fed five diets containing organic zinc at 30, 70, 110 and 150 mg kg,1 diet and one inorganic zinc source (zinc oxide) at 150 mg kg,1 diet for a period of 12 weeks. No significant (P>0.05) differences were found in the growth performance parameters (final weight, specific growth rate), immunological indices tested (respiratory burst activity in whole blood) and the wound-healing process. Zinc accumulation in the skin, vertebrae and liver increased significantly (P<0.01) with increased dietary zinc levels but not in muscle. The highest zinc concentrations were obtained in skin tissue, followed by vertebrae, liver and muscle tissue. Using the concentration of zinc in skin as a response criterion, broken-line analysis showed that the supplementation of 148 mg organic Zn kg,1 diet seemed to be the optimum dietary zinc supplementation level for sea bass juveniles. [source] Alternative matrices for cortisol measurement in fishAQUACULTURE RESEARCH, Issue 8 2010Daniela Bertotto Abstract Plasma cortisol is the most commonly used indicator of stress in fish but, as the blood sampling procedure itself can be a source of stress, it would be helpful to measure cortisol using less invasive matrices. It is also necessary to find alternative matrices as stress indicators in dead fish in which blood sampling is impossible. In the present study, we investigated transport stress in three aquaculture species, European sea bass (Dicentrarchus labrax L.), common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin mucus, gut content, lateral muscle and caudal fin). Cortisol significantly increased after transport in all species and matrices, except in the sea bass gut content, where it remained unchanged. The three species responded to transport stress by producing different cortisol levels. In conclusion, the significant correlation found between plasma cortisol and most of the other matrices opens up the possibility of using them to evaluate stress in fish: mucus sampling is a less invasive method than blood sampling, and in addition to muscle and fin sampling, it can be used in postmortem fish. [source] Nutrient digestibility profile of premium (category III grade) animal protein by-products for temperate marine fish species (European sea bass, gilthead sea bream and turbot)AQUACULTURE RESEARCH, Issue 15 2009Simon J Davies Abstract Three trials, with classical experimental designs for in vivo digestibility studies, were conducted to determine the apparent digestibility coefficient (ADC) of protein (ADCp), lipid (ADCl), energy (ADCe) and amino acids (AA) in selected animal by-products fed to European sea bass, Dicentrarchus labrax (Trial 1), gilthead sea bream, Sparus aurata (Trial 2), and turbot, Psetta maxima (Trial 3). In each trial, five experimental diets [including a reference diet (RD)] where fish meal (FM) was used as the sole protein source were fed ad libitum to the fish for a period of 4 weeks. Test diets were based on the FM RD and obtained by replacing 30% of the RD with a category III designated European animal by-products (fit for human consumption), namely: steam hydrolysed feather meal (HFM), enzyme-treated feather meal (EFM), poultry meat meal (PMM) and spray-dried haemoglobin meal (SDHM). Faecal material was collected using the ,Guelph system', and nutrient and energy digestibility coefficients were related to the measurement of chromic oxide (Cr2O3) incorporated into the diet at a rate of 0.5%. Without any exception, FM diets yielded the best digestibility values for all macro-nutrients and by all fish. Among the test ingredients, ADCp was consistently higher for PMM and SDHM in the three species (85.5%, 91.1% in sea bass; 79.2%, 82.8% in sea bream; and 78.4%, 74.8% in turbot). Conversely, ADCp of HFM and EFM were less efficiently digested (67.2%, 68.2% in sea bass; 21.5%, 21.7% in sea bream; and 46.6%, 36.0% in turbot). However, the novel processing method applied to feather meal did not considerably influence the digestibility of most of the nutrients in this feedstuff. The current investigation yielded valuable numerical ADC for EAA considered to be of prime importance in generating balanced diet formulations. [source] A preliminary study on the utilization of hazelnut meal as a substitute for fish meal in diets of European sea bass (Dicentrarchus labrax L.)AQUACULTURE RESEARCH, Issue 3 2008lmaz Emre First page of article [source] | ||||||||||||||||