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Sea Bass (sea + bass)
Kinds of Sea Bass Terms modified by Sea Bass Selected AbstractsEffects of High Pressure on Texture and Microstructure of Sea Bass (Dicentrarchus labrax L.) FilletsJOURNAL OF FOOD SCIENCE, Issue 8 2005Romuald Chéret ABSTRACT High pressure is an innovative non-thermal food-preservation technology. We studied the effect of high-pressure treatment up to 500 MPa for 5 min on physical characteristics of sea bass fillets after 0, 7, and 14 d of refrigerated storage. Color results exhibited an increase of lightness and a slight change of hue, which might be imperceptible in cooked fish. High-pressure treatment induced a decrease of exudation and water-holding capacity. Pressure treatment above 300 MPa provoked higher fish hardness after storage than in untreated sample, proving the ability of high pressure to improve textural quality of chilled, stored fish fillet. These assessments were corroborated with microstructure observations. We showed that high-pressure treatment at 500 MPa allowed, after 7 d of storage, a total aerobic count equivalent to that of untreated fresh fish fillet to be obtained. Thus, high pressure might be considered to be a technology able to improve safety and textural quality of fresh fish fillets. [source] Muscle Cellularity at Cranial and Caudal Levels of the Trunk Musculature of Commercial Size Sea Bass, Dicentrarchus labrax (Linnaeus, 1758)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2005I. Abdel Summary In eight specimens of Atlantic sea bass of commercial size (,350 g) muscle cellularity was studied at two selected sampling levels of the trunk axial musculature: caudal (anal opening) and cranial (fourth radius of the dorsal fin). The following parameters were quantified at both sampling levels: white muscle cross-sectional area, white muscle fibre diameter (900,1200 fibres), muscle fibre number and muscle fibre density. Results showed a higher total cross-sectional area at cranial than at caudal level (P < 0.05), what is related with their different gross morphology. However, the white muscle fibre size distribution, as well as the muscle fibre number and density did not show significant differences between them. This study contributes to typify muscle fibre sampling in sea bass of commercial size what is of great interest for morphometric studies where white muscle cellularity is commonly correlated with textural or organoleptic parameters. [source] Determination of physical behaviour of feed pellets in Mediterranean waterAQUACULTURE RESEARCH, Issue 2 2006Paolo Vassallo Abstract Settled uneaten feed causes the most intense impact under sea cages, and settling velocity of the feed pellets represents a key parameter for waste dispersion models. Even if some data about physical properties of feed pellets have been published in the framework of salmonid rearing, there is a complete lack of information related to the Mediterranean Sea, as regards typical values of temperature, salinity and feed composition for Gilthead Sea Bream (Sparus aurata L.) and Sea Bass (Dicentrarchus labrax L.). In this study we try to fill this lack, determining dimensions, water adsorption properties, floating times and settling velocities of a typical growing sequence of pellets for the species mentioned above, under defined laboratory conditions reproducing Mediterranean Sea water. The settling velocity increases with pellet size from 0.087, for the smallest pellet (3 mm), to 0.144 m s,1, for the 5 mm pellet. The biggest extruded pellet (6 mm) falls slower (0.088 m s,1). The floating time before pellet's fall is found to be a critical parameter in determining settling velocity. The latter depends on pellet's size, water temperature and salinity. The examined pellets reach a 42% of weight increase after 10 min of immersion, while no appreciable dimension change is observed. Our results are in part different from previous ones and could play a role in evaluating and modelling Mediterranean aquaculture environmental impact. [source] Vaccination trials of sea bass, Dicentrarchus labrax (L.), against Photobacterium damsela subsp. piscicida, using novel vaccine mixturesJOURNAL OF FISH DISEASES, Issue 2 2003V Bakopoulos Abstract Bacterial cells of the marine fish pathogen Photobacterium damsela subsp. piscicida were grown in novel culture media. A mixture of whole cells and extracellular components was inactivated and used in bath, intraperitoneal (i.p.) and oral vaccination of sea bass, Dicentrarchus labrax, employing two sizes of fish. A commercial vaccine was used for comparative purposes. Control and immunized fish were either bath or intraperitoneally challenged 6 and 12 weeks post-vaccination. Small fish had significantly higher relative percentage survival with the novel vaccine mixture both at 6 and 12 weeks post-vaccination by bath, in comparison with the commercial vaccine. No protection was afforded at 6 or 12 weeks post-immunization by either vaccine after challenge via i.p. injection. Sea bass (1.5,2 g) intraperitoneally vaccinated with various adjuvanted vaccine mixtures were not protected against pasteurellosis. In contrast, larger sea bass (20 g) benefited from vaccination with the novel vaccine mixtures. Intraperitoneal challenge with the pathogen resulted in protection in both fish groups vaccinated with novel vaccine mixtures, whereas control fish suffered high mortalities (>80%). Orally vaccinated fish were immersion challenged with the pathogen. At 6 and 12 weeks post-vaccination the control fish had a high mortality and the fish vaccinated with the novel vaccine mixture achieved good protection. [source] Quality Characteristics of Sea Bass Intensively Reared and from Lagoon as Affected by Growth Conditions and the Aquatic EnvironmentJOURNAL OF FOOD SCIENCE, Issue 2 2002E. Orban ABSTRACT: Sea bass (Dicentrarchus labrax) of commercial size free-living in the lagoon of Orbetello (Tuscany, Italy) and from intensive rearing were compared for proximate composition, essential and toxic metals, unsaponifiable lipids, and for the fatty acid profile of total, neutral, and polar lipids. Farmed sea bass had a total lipid content (10.57 ± 0.17g/100g) significantly higher (P , 0.001) than fish in the wild (1.78 ± 0.01 g/100g). Fish from either productive systems showed comparably high total polyunsaturated fatty acid levels and n-3/n-6 ratio values. Differences in the mineral content occurred among fish, particularly in the levels of mercury and selenium, significantly higher in those from the lagoon. [source] Influence of tank volume on vitellogenesis and spawning performances in sea bass Dicentrarchus labrax L.AQUACULTURE RESEARCH, Issue 4 2008Vincent Buchet Abstract Sea bass, Dicentrarchus labrax (mean weight: 748±13 g), were maintained before and during vitellogenesis in 1, 3, 8, 16 and 32 m3 tanks, and then they were transferred to 2 m3 tanks, for the spawning season. During the first 2 months of the experiment, the growth rates were significantly lower in smaller tanks (1 m3). In August, the oocyte diameters were significantly lower in smaller tanks (1, 3 and 8 m3) than in larger (16,32 m3) tanks. At the end of the experiment, the fish mean weight in the 1 m3 tanks was significantly lower than in the 3 m3 tanks, but oocyte diameters and plasma oestradiol concentrations were not significantly different between the volumes. This shows a longer acclimation requirement in smaller volume rearing. Although all the females had not spawned, one spawn at least was collected in each volume. The variation in conditioning volume has not blocked the spawning process. The qualitative and quantitative characteristics of spawns were not significantly different between volumes. The conditioning volume of 3 m3 seems to be a minimal volume required to obtain good reproduction of sea bass. [source] Development of a bacterial challenge test for gnotobiotic sea bass (Dicentrarchus labrax) larvaeENVIRONMENTAL MICROBIOLOGY, Issue 2 2009K. Dierckens Summary The use of probiotic microorganisms in aquaculture is gaining a lot of interest. Gnotobiotic model systems are required in order to fully understand the effects and modes-of-action of these microorganisms, as the native microbial communities present in non-sterile animals can lead to false conclusions. In this study, a gnotobiotic sea bass larvae (Dicentrarchus labrax) test system was developed. In order to obtain bacteria-free animals, the eggs were disinfected with glutaraldehyde and subsequently incubated in a solution of rifampicin and ampicillin. Axenity was confirmed using culture-dependent and -independent techniques. The gnotobiotic larvae were fed axenic Artemia sp. from 7 days after hatching onwards. In the challenge test, one of the three opportunistic pathogens, Aeromonas hydrophila, Listonella anguillarum serovar O1 and O2a, was added to the model system via the water and encapsulated in Artemia sp. Only serovar O2a led to increased mortality in the sea bass larvae. The presented gnotobiotic model can be used for research on, among others, reciprocal metabolic effects between microorganisms and the host (e.g. as measured by gene expression), immunostimulants, pharmacological research and the histological development of the gastrointestinal tract and growth of larvae. [source] Introduction of a new physiological acoustic electromyogram transmitterFISHERIES MANAGEMENT & ECOLOGY, Issue 5-6 2008G. LEMBO Abstract, Electromyogram (EMG) radio transmitters have proven to be a useful tool to monitor activity levels in free swimming fish. Unfortunately, the availability of the EMG transmitter in only radio mode limited its use to the freshwater environment. Applications in the marine environment are numerous and include monitoring activity levels in both wild and cultured finfish. This study presents preliminary data from trials examining activity levels in free swimming sea bass, Dicentrarchus labrax, L., using an acoustic EMG transmitter. Three adult sea bass were surgically implanted with the newly created prototype EMG transmitters. Signals from the transmitter were calibrated to swimming speed using a Bla,ka-style chamber. Swimming trials showed a high correlation between EMG signal and swimming velocity (r2 = 0.978) and were described using a sigmoid model. No significant differences (P < 0.05) were found among the four swimming trials conducted on the same fish or among the trials of the three different fish, indicating minimum variation from the prototypes tested. [source] Original article: Effect of modified atmosphere packaging using different CO2 and N2 combinations on physical, chemical, microbiological and sensory changes of fresh sea bass (Dicentrarchus labrax) filletsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2010Laura Provincial Summary The effect of different modified atmosphere packaging (MAPs) on physical, chemical, microbiological and sensory changes of sea bass fillets when stored at 4 °C and standard light conditions was investigated for up to 21 days and compared to a control batch stored in overwrap. Sea bass fillets were packed using different CO2 and N2 combinations (40% CO2,60% N2; 50% CO2,50% N2; 60% CO2,40% N2), and quality assessment was based on instrumental, chemical, microbiological and sensory analysis. The results showed that MAP extended shelf-life of sea bass fillets from 7 days (overwrap packaging) to 14 days. Drip loss, pH values and thiobarbituric acid reactive substances (TBARS) measurements were higher in overwrap samples but no differences (P , 0.05) were found between MAP samples. Bacteria grew most quickly and showed higher counts in overwrap samples followed by 40% CO2,60% N2; 50% CO2,50% N2 and finally 60% CO2,40% N2. Sensory analyses were in good relation with chemical and microbiological results establishing best scores and an extended shelf-life for MAP samples especially in MAPs with high CO2 levels. [source] Effect of soluble CO2 stabilisation and vacuum packaging in the shelf life of farmed sea bream and sea bass filletsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2008Rogério Mendes Summary The objective of this study was to determine the differences of sensory, microbiological and chemical quality in vacuum-packaged fillets of sea bream and sea bass previously submitted to soluble gas solubilisation (SGS) with 100% CO2, at 2 bar for 30 and 60 min and stored at chilled temperature for 15 days. Apart from pH value that showed a regular increase during chilled storage, the other chemical index [total volatile bases nitrogen (TVB-N), trimethylamine nitrogen (TMA-N) and thiobarbituric acid reactive substances (TBARs)] had showed to be poor indicators of changes in quality of products. Final TVB-N values ranged from 16.0 to 17.4 mg N per 100 g and from 17.3 to 19.4 mg N per 100 g in sea bream and sea bass, respectively. Sensory evaluation resulted as the most reliable parameter of quality decay. The results show that SGS treatment kept the initial quality of fillets for longer time, which was particularly visible on the sea bream fillets, thus contributing to an extension in 2,3 days of the shelf life. SGS had also a positive effect in the delay of microbial growth. [source] Effects of differences in diet and seasonal changes on the fatty acid composition in fillets from farmed and wild sea bream (Sparus aurata L.) and sea bass (Dicentrarchus labrax L.)INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2008Mustafa Yildiz Summary The effects of dietary fatty acids and seasonal variation on the fatty acid profiles of farmed and wild sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) were determined by analysis of their fillets. Farmed sea bream and sea bass were fed on the same commercial feeds all year. Fatty acid profiles in the fillets reflected the fatty acid profiles of the commercial feeds. The predominant fatty acids in the trial feeds, fillets of farmed and wild sea bream and sea bass were 16:0, 18:1n -9, 18:2n -6, 20:5n -3 and 22:6n -3. The fatty acid profiles in the fillets of farmed sea bream and sea bass did not differ (P > 0.05) except in the winter season compared with those of their wild counterparts. However, the content of eicosapentaenoic acid (20:5n -3), docosahexaenoic acid (22:6n -3) in the fillets of the farmed and wild sea bass were significantly (P < 0.05) higher than the farmed and wild sea bream. The wild sea bream had significantly (P < 0.05) higher total saturated fatty acid and monounsaturated fatty acid (MUFA) levels, and lower total n -6 and n -3 polyunsaturated fatty acid (PUFA) levels in winter than in the summer and spring seasons. Similarly, in the fillets of wild sea bass, total n -3 PUFA levels were significantly (P < 0.05) lower, and the MUFA levels were higher in winter than in the other seasons. These results indicate that the farmed fish fillets were good sources of n -3 PUFA in each of the three seasons. However, wild fish were good sources of n -3 PUFA in the spring and summer. [source] Sensory, 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] Estuarine colonization, population structure and nursery functioning for 0-group sea bass (Dicentrarchus labrax), flounder (Platichthys flesus) and sole (Solea solea) in a mesotidal temperate estuaryJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2008F. Martinho Summary The function of the Mondego estuary as a fish nursery habitat was investigated from June 2003 to June 2004 by comparing the timing of estuarine colonization with juveniles of sea bass Dicentrarchus labrax, flounder Platichthys flesus, and sole Solea solea, while also analysing their population structure, growth and diet composition. Differences in the onset of estuarine colonization were observed, since sole juveniles were the first to enter the estuary (in January), followed by flounder in April and sea bass in June. The estuarine population of these species consisted of several age-groups, although the majority of individuals belonged to age-groups 0 and 1. The growth rates determined for 0-group fish were within the range of those reported for other European estuarine systems. Some differences were also recognized regarding the timing of estuarine colonization and the length of the growing season. Diet of 0-group sea bass consisted mainly of Crustacea, Polychaeta and Mollusca. Flounder juveniles fed chiefly on Amphipoda (especially Corophium spp.), with Polychaeta, Isopoda and Decapoda also being common prey. The diet of 0-group sole was dominated by Polychaeta, with Amphipoda, Mollusca and Decapoda ranking highest, with other important benthic organisms also being present. Dietary overlap among these species was relatively low. [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] Pathological and epidemiological observations on rickettsiosis in cultured sea bass (Dicentrarchus labrax L.) from GreeceJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2004F. Athanassopoulou Summary A systemic infection of a Rickettsia -like organism (RLO) in cultured sea bass is described for the first time. In hatcheries, clinical signs were lethargy, inappetence and discoloration. Twenty days after transfer to sea cages from hatcheries where the disease existed, fish showed erratic and abnormal swimming behaviour, loss of orientation, and lethargy. Cumulative mortality in colder months of the year reached 30% in hatcheries and 80% in cages. Surviving fish in cages did not show any clinical signs of RLO infection in the subsequent year. Evidence for a systemic distribution of RLO was supported by histolopathological lesions in both infected hatchery and caged fish, where the lesion profile included cranial sensory, central nervous, integumental and alimentary organ systems. Intracranial lesions were primarily characterized by an ascending histiocytic perineuritis and necrotizing congestive meningoencephalitis, with evidence for transfer of infective agents across the blood,brain barrier confirmed by the presence of RLOs within capillary endothelium and histiocytes in inflamed regions of the optic tectum and the cerebellum. In the most severe cases, infection spread to the statoacoustical (semicircular) canal system and the ependymal lining of ventricles, with marked rickettsial-laden histiocytic infiltration of the canal lumen. Integumental lesions were restricted to the oral submucosa, nares and integumental dermis of the cranium. Alimentary lesions were noted in both the liver parenchyma and mucosa/submucosa of the stomach. In all affected organs the RLOs were found by immunohistochemistry to be related to Piscirickettsia salmonis. [source] Genetic interactions between marine finfish species in European aquaculture and wild conspecificsJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2001Youngson The principal species of marine aquaculture in Europe are Atlantic salmon (Salmo salar), sea bass (Dicentrarchus labrax) and sea bream (Sparus auratus). For Atlantic salmon and sea bass, a substantial part of total genetic variation is partitioned at the geographical population level. In the case of sea bream, gene flow across the Azores/Mediterranean scale appears to be extensive and population structuring is not detected. For Atlantic salmon and sea bass, natural population structure is at risk from genetic interaction with escaped aquaculture conspecifics. The locally adaptive features of populations are at risk from interbreeding with non-local aquaculture fish. Wild populations, generally, are at risk from interactions with aquaculture fish that have been subject to artificial selection or domestication. Atlantic salmon is the main European aquaculture species and its population genetics and ecology have been well-studied. A general case regarding genetic interactions can be based on the information available for salmon and extended to cover other species, in the appropriate context. A generalized flow chart for interactions is presented. Salmon escape from aquaculture at all life stages, and some survive to breed among wild salmon. Reproductive fitness in the escaped fish is lower than in native, wild fish because of behavioural deficiencies at spawning. However, as the number of salmon in aquaculture greatly exceeds the number of wild fish, even small fractional rates of escape may result in the local presence of large numbers, and high frequencies, of escaped fish. At present, policy and legislation in relation to minimizing genetic interactions between wild and aquaculture fish is best developed for Atlantic salmon, through the recommendations of the Oslo Agreement developed by the North Atlantic Salmon Conservation Organization and subsequent agreements on their implementation. In future, the potential use of genetically modified fish in aquaculture will make additional policy development necessary. Improved containment is recommended as the key to minimizing the numbers and therefore the effects of escaped fish. Emergency recovery procedures are recommended as a back-up measure in the case of containment failure. Reproductive sterility is recommended as a future key to eliminating the genetic potential of escaped fish. The maintenance of robust populations of wild fish is recommended as a key to minimizing the effects of escaped fish on wild populations. [source] Changes in serum cortisol, metabolites, osmotic pressure and electrolytes in response to different blood sampling procedures in cultured sea bass (Dicentrarchus labrax L.)JOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2001Marino This study investigated the effect of five sampling procedures on serum cortisol, glucose, total protein, osmolality, Na+, Cl,, K+ and Ca++ concentrations in 2-year-old cultured sea bass (Dicentrarchus labrax L). Mild disturbance caused by rapid removal of fish and brief handling did not induce significant variation in any of the blood parameters investigated. Confinement and crowding elicited a high and significant increase in serum cortisol, glucose, osmolality, Na+, Cl,, and Ca++ concentrations. Exposure to MS 222 (140 mg L,1) significantly increased osmolality, but not ionic concentration. Site of blood withdrawal (cardiac sinuses/caudal vein) had no effect on the concentration of analysed blood constituents, except for K+ levels. Scattered literature of sea bass blood chemistry is reviewed and compared with ,normal' ranges of blood constituents measured in this study. We conclude that it is necessary to select and rigorously execute an opportune blood sampling procedure whenever blood constituents are used as indicators of fish functional state. [source] A review of marine aquaculture in Spain: production, regulations and environmental monitoringJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4-5 2000A. Sánchez-Mata Summary In this review the main aspects concerning Spanish marine aquaculture production, and its control, are summarized. Aquaculture in Spain has been dominated by extensive shellfish farming, mainly mussels (3242 rafts; 260 000 t year -1 in 1998), since the beginning of the 1950s. This type of farming was the most lucrative marine aquaculture activity in the Galician Rías (NW of the Iberian Peninsula) in terms of production. In recent years, finfish farming has developed in a number of Mediterranean locations, with turbot, sea bream and sea bass as the most important species produced (18 300 t year -1 in 1998). Environmental, food-quality and medicine standards are also reviewed in this paper including the regulations, rules, farm licensing, permits and monitoring programmes involved. [source] Nutritional evaluation of various plant protein sources in diets for Asian sea bass Lates calcariferJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2000By P. S. Eusebio A biological assay was conducted to evaluate the suitability of various leguminous seed meals and leaf meals as dietary protein sources for Asian sea bass, Lates calcarifer. In the growth experiment, fish (initial mean weight ±,standard error (SE) of 3.8 ± 0.5 g) were fed isonitrogenous and isocaloric diets containing test ingredients to replace 13,18% of the diet. The same diet formulations were used in a digestibility experiment, except that 1% Cr2O3 was added as an external indicator. The growth of the control fish was comparable to fish fed leguminous seed meal-based diets, and better than those given leaf meal-based diets. The control diet had the highest apparent protein digestibility (APD) value. No significant differences were observed between the APD of white cowpea (Vigna unguiculata), green mungbean (V. radiata) and papaya (Carica papaya) leaf meal-based diets. However, the cassava (Manihot esculenta) leaf meal-based diet had the lowest APD value. The present findings suggest that white cowpea and green mungbean meals can be used as protein sources in practical diets to replace 18% of the sea bass diet without affecting their growth. [source] Development of the lateral line system in the sea bassJOURNAL OF FISH BIOLOGY, Issue 1 2003J. P. Diaz Using light and electron microscopy, a study of the development of the lateral line system of the sea bass Dicentrarchus labrax, from embryo to adult, revealed that the first free neuromasts appeared on the head shortly before hatching and multiplied during the larval stage. They were aligned on the head and trunk in a pattern which corresponded to the location of future canals. The transition to the juvenile stage marked the start of important anatomical changes during which head and trunk canals were formed successively. Neuromasts, with a cupula and consisting of standard sensory cells and supporting cells, were characterized by bidirectional polarity. The exact location of the first neuromast formed in the embryo was identified and its differentiation monitored from primordium to eruption. This neuromast was distinguishable from the others by its radial polarity. Correlations were made between the development of the lateral line system and the behaviour of the sea bass. [source] Vaccination trials of sea bass, Dicentrarchus labrax (L.), against Photobacterium damsela subsp. piscicida, using novel vaccine mixturesJOURNAL OF FISH DISEASES, Issue 2 2003V Bakopoulos Abstract Bacterial cells of the marine fish pathogen Photobacterium damsela subsp. piscicida were grown in novel culture media. A mixture of whole cells and extracellular components was inactivated and used in bath, intraperitoneal (i.p.) and oral vaccination of sea bass, Dicentrarchus labrax, employing two sizes of fish. A commercial vaccine was used for comparative purposes. Control and immunized fish were either bath or intraperitoneally challenged 6 and 12 weeks post-vaccination. Small fish had significantly higher relative percentage survival with the novel vaccine mixture both at 6 and 12 weeks post-vaccination by bath, in comparison with the commercial vaccine. No protection was afforded at 6 or 12 weeks post-immunization by either vaccine after challenge via i.p. injection. Sea bass (1.5,2 g) intraperitoneally vaccinated with various adjuvanted vaccine mixtures were not protected against pasteurellosis. In contrast, larger sea bass (20 g) benefited from vaccination with the novel vaccine mixtures. Intraperitoneal challenge with the pathogen resulted in protection in both fish groups vaccinated with novel vaccine mixtures, whereas control fish suffered high mortalities (>80%). Orally vaccinated fish were immersion challenged with the pathogen. At 6 and 12 weeks post-vaccination the control fish had a high mortality and the fish vaccinated with the novel vaccine mixture achieved good protection. [source] The production and characterization of monoclonal antibodies against Photobacterium damselae ssp. piscicida and initial observations using immunohistochemistryJOURNAL OF FISH DISEASES, Issue 2 2001T S Jung Five monoclonal antibodies (MAbs: F2B1, 1E4, 13B10, 4D4 and F3G12) were produced against lysed Photobacterium damselae ssp. piscicida (Ph. d. ssp. piscicida). The MAbs recognized three antigens of differing molecular weight on the Western blot of Ph. d. ssp. piscicida. They also cross-reacted with five different species of Vibrio. An enzyme linked immunosorbent assay (ELISA) with MAbs, F3G12 and 4D4 demonstrated differences between Ph. d. ssp. piscicida and three Ph. d. ssp. damselae type strains, indicating differences in the surface antigenicity between these two groups of bacteria. Antigen retrieval in conjunction with immunohistochemistry (IHC) using MAb 13B10, revealed colonies of bacteria in the kidney, spleen and liver of sea bass, Dicentrarchus labrax, infected with pasteurellosis. A number of positive colonies were observed around the mucosal layers of the intestinal tissue, especially within the lamina propria. In addition, a number of bacterial colonies were associated with red blood cells and blood vessels of the organs examined. [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] Quality Characteristics of Sea Bass Intensively Reared and from Lagoon as Affected by Growth Conditions and the Aquatic EnvironmentJOURNAL OF FOOD SCIENCE, Issue 2 2002E. Orban ABSTRACT: Sea bass (Dicentrarchus labrax) of commercial size free-living in the lagoon of Orbetello (Tuscany, Italy) and from intensive rearing were compared for proximate composition, essential and toxic metals, unsaponifiable lipids, and for the fatty acid profile of total, neutral, and polar lipids. Farmed sea bass had a total lipid content (10.57 ± 0.17g/100g) significantly higher (P , 0.001) than fish in the wild (1.78 ± 0.01 g/100g). Fish from either productive systems showed comparably high total polyunsaturated fatty acid levels and n-3/n-6 ratio values. Differences in the mineral content occurred among fish, particularly in the levels of mercury and selenium, significantly higher in those from the lagoon. [source] Microbiological, chemical and sensory changes of whole and filleted Mediterranean aquacultured sea bass (Dicentrarchus labrax) stored in iceJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2003Dimitra Taliadourou Abstract The effect of filleting on the microbiological, chemical and sensory properties of aquacultured sea bass (Dicentrarchus labrax) stored in ice was studied. Pseudomonads, H2S-producing bacteria (including Shewanella putrefaciens) and Brochothrix thermosphacta were the dominant bacteria at the end of the 16 day storage period in ice for both whole ungutted and filleted sea bass. Enterobacteriaceae were also found in the spoilage microflora of whole ungutted and filleted sea bass, but their counts were always lower than those of pseudomonads, H2S-producing bacteria (including S putrefaciens) and B thermosphacta. Total viable counts for whole ungutted sea bass were always lower than those for filleted sea bass samples. Of the chemical indicators of spoilage, TMA (trimethylamine) values of whole ungutted sea bass increased very slowly, whereas significantly higher values were obtained for filleted samples, with respective values of 0.253 and 1.515 mg N per 100 g muscle being reached at the end of their shelf-life (days 13 and 9 respectively). TVB-N (total volatile basic nitrogen) values showed a slight increase for whole ungutted sea bass during storage, reaching a value of 26.77 mg N per 100 g muscle (day 13), whereas for filleted fish a corresponding value of 26.88 mg N per 100 g muscle was recorded (day 9). TBA (thiobarbituric acid) values increased slowly for whole ungutted and filleted sea bass samples throughout the entire storage period, reaching final values of 4.48 (day 13) and 13.84 (day 9) mg malonaldehyde kg,1 respectively. Sensory assessment of raw fish using the EC freshness scale gave a grade E for up to 5 days for whole ungutted sea bass, a grade A for a further 4 days and a grade B for an additional 4 days, after which sea bass was graded as C (unfit). Overall acceptability scores for odour, taste and texture of cooked whole ungutted and filleted sea bass decreased with increasing time of storage. The results of this study indicate that the shelf-life of sea bass stored in ice, as determined by overall acceptability sensory scores and microbiological data, is 8,9 days for filleted and 12,13 days for whole ungutted fish. Copyright © 2003 Society of Chemical Industry [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] The Effects of Temperature and Salinity on Early Life Stages of Black Sea Bass Centropristis striataJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2004David L. Berlinsky Along the Atlantic coast black sea bass occur from the Gulf of Maine to Florida and support important commercial and recreational fisheries. Interest in commercial production of black sea bass has increased in recent years due to high demand and limited seasonable availability. Efforts towards large-scale production have been hampered by a high incidence of early larval mortality. Two of the most important environmental variables affecting hatchery production of marine finfish larvae are temperature and salinity. In the wild, larval black sea bass are found in waters with temperatures of 12,24 C and salinity levels of 30,35 ppt. Studies were conducted to define the temperature and salinity ranges that support growth and development of black sea bass during early life stages. Three developmental phases were investigated: 1) fertilization to hatch: 2) hatch through yolk sac absorption: and 3) during the initial exogenous feeding stage (5,14 days post hatch: DPH). Fertilized eggs were obtained by manual spawning of fish following administration of LHRHa. Fertilized eggs were transferred to 300-mL glass Petri dishes or 500-mL beakers to assess the effects of salinity and temperature through hatch and yolk sac absorption, respectively. To determine environmental effects on growth and survival during initial exogenous feeding 400 actively feeding larvae were cultured in green water and fed enriched rotifers for a 9-d period. For investigation of the effect of salinity, sea water (35 ppt) was diluted gradually to 15, 20, 25, and 30 ppt and maintained at 21 C. For examination of the effect of temperature, seawater was adjusted from 21 C to 12, 15, 21, 27, or 30 C at a rate of 3 C/h. No eggs hatched at 12 C or when salinity was maintained at 0 or 5 ppt. Hatching was uniformly high (, 85%) at temperatures between 15 and 27 C and at salinities , 15 ppt. Survival through yolk sac absorption was greatest at temperatures between 18 and 27 C and at salinities , 20 ppt. Survival through first feeding stage was highest at temperatures , 18 C and 30 ppt salinity. Larval growth through first feeding was not significantly affected by salinity level but did increase with rearing temperature. The results indicate that survival and development of black sea bass during early life stages are most favorable at temperatures >18 C with salinity levels approaching full strength seawater. [source] Identification and pathogenicity of Vibrio ponticus affecting cultured Japanese sea bass, Lateolabrax japonicus (Cuvier in Cuvier and Valenciennes)LETTERS IN APPLIED MICROBIOLOGY, Issue 1 2007Z.Y. Xie Abstract Aims:, To rapidly determine the causative agent of mass death in Lateolabrax japonicus in Zhelin Bay of Guangdong Province in China in April 2004. Methods and Results:, Thirty-six strains, numbered sequentially from RP01 to RP36, were isolated from six diseased fish. All of the strains were identified as being of the same vibrio species according to the results of universal primer PCR combined with DGGE (UPPCR-DGGE). RP30 was one of these strains that was randomly selected and analysed by using a morphological, physiological and biochemical plate, Biolog GN2 Microplate System and API 20E system. Furthermore, RP30, 16S rDNA was sequenced and aligned in Genbank. Its virulence to Lateolabrax japonicus (Cuvier in Cuvier and Valenciennes) was also tested. RP30 is most closely related to four Vibrio ponticus strains (99·3% similarity). LD50s were 2·5 (×103 CFU per fish for intraperitoneal inoculation (IP) and 3·2 (×103 CFU per fish for intramuscular inoculation (IM), respectively. Conclusions:, The investigated pathogenic agent of Lateolabrax japonicus (Cuvier in Cuvier and Valenciennes) was V. ponticus. Significance and Impact of the Study:, UPPCR-DGGE is very helpful in epidemiologic investigation. Interestingly, this is the first report that V. ponticus infects cultured marine fish. DGGE was likewise first introduced to epidemiologic investigation of fish disease. [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] | ||||||||||||||||