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Registros recuperados: 79 | |
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Lavens, P.; Sorgeloos, P.. |
A flow-through culture system is described for the controlled production of <i>Artemia</i> cysts in 10 liter aquaria using 50 promille artificial seawater enriched with Fe-EDTA as culture medium, micronised rice bran as food source and cyclic flushes of the cultures with N<sub>2</sub>-gas as induction mechanism for oviparity. The culture water is recirculated over a rotating biological contactor, a settling tank and a UV disinfection unit. Cysts are continuously harvested by filtration of the culture effluent. Production yields average 0.5 g dry cysts per day and per aquarium. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aquaculture techniques; Artemia. |
Ano: 1984 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3267 |
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Nelis, H.J.; Merchie, G.; Lavens, P.; Sorgeloos, P.; De Leenheer, A.P.. |
Two producers are described for the solid-phase extraction of ascorbic acid 2-sulfate from cysts of the brine shrimp <i>Artemia</i> . The first one is based on reversed-phase ion pair extraction on an octadecylsilica cartridge using tetrabutylammonium as the counterion, followed by elution with methanol. In the second procedure ascorbic acid 2-sulfate is retained on a DEAE silica cartridge and eluted with 0.1M sodium salicylate. Both approaches were used as part of a quantitative reversed-phase ion pair liquid chromatographic method with detection at 254nm. The anion exchange extraction procedure is superior to its ion pair counterpart in terms of recovery (88.7±3,5% versus 63.0±12.7%), reproducibility (CVs of 3.6-7.7% versus 6.3-18.7%), and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia franciscana. |
Ano: 1994 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2643 |
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Lavens, P.; Sorgeloos, P.. |
A flow-through system is described for the controlled production of <i>Artemia</i> nauplii. High densities of adult brine shrimp are induced to ovoviviparity through diet manipulation, optimal culture water exchange, and high constant oxygen levels. The nauplii produced are separated from the culture tank effluents in a special recuperation filter system. The culture water is recirculated over a rotating biodisc, a cross-flow sieve, and a plate separator.The potential of this nauplii production system for application in aquaculture hatcheries is discussed. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
Ano: 1987 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3174 |
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Coutteau, P.; Brendonck, L.; Lavens, P.; Sorgeloos, P.. |
The production of unicellular algae is laborious and is a major constraint for the culturing of aquatic filter-feeders. Because of their small particle size and their high protein content yeasts are considered as a promising substitute for micro-algae. Furthermore, recent work has shown that baker's yeast can be converted into a digestible diet for <i>Artemia</i> by chemical treatment. The present study documents the use at laboratory scale of this manipulated yeast as an algal substitute for the culture of two anostracan species.The experiments were conducted with the brine shrimp <i>Artemia franciscana</i> and the fairy shrimp <i>Streptocephalus proboscideus</i>. A similar experimental set-up was used for both species.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anostraca. |
Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2720 |
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Sorgeloos, P.; Dehasque, M.; Dhert, Ph.; Lavens, P.. |
Dependable availability of quality fry to stock grow-out production systems has been one of the most critical factors in the commercial success of industrial production of fish and shellfish. Large-scale production of marine fish fry was realized only from the 1980s onwards. Although Japan was the pioneer with the red sea bream (<i>Pagrus major</i>), the most competitive hatchery methods were eventually developed in Europe for the sea bass (<i>Dicentrarchus labrax</i>) and the gilthead sea bream (<i>Sparus aurata</i>). Improved knowledge of larval dietary requirements, not the least with regard to (n-3) highly unsaturated fatty acids (HUFAs), combined with the adoption of live-food enrichment protocols allowed the... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2627 |
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Nelis, H.; Lavens, P.; Sorgeloos, P.; Van Steenberge, M.; De Leenheer, A.P.. |
The carotenoid composition of <i>Artemia</i> cysts from 17 geographical strains was studied. All-<i>trans</i>-canthaxanthins and <i>cis</i>-canthaxanthins were quantitatively determined using a non-aqueous reversed phase chromatographic method. In dehydrated cysts, the average <i>cis</i>- and <i>trans</i>-canthaxanthin levels (+/- SD) were 152 +/- 52 and 134 +/- 42 µg/g, respectively (range 38-227 and 67-201µg/g). The corresponding concentrations in hydrated cysts were (<i>cis</i>) 177 +/- 60 µg/g (range 47-271 µg/g) and (<i>trans</i>) 112 +/- 35 µg/g (range 52-169 µg/g). The <i>cis/trans</i> concentration ratios averaged 1.13 (range 0.57-1.47) and 1.60 (range... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
Ano: 1987 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3196 |
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Peleteiro, J.B.; Lavens, P.; Rodríguez-Ojeja, G.; Iglesias, J.. |
The paper presents the data relating to the spawning quality of 20 turbot females (<i>Scophthalmus maximus</i>L.) subjected to natural and controlled photoperiods and fed with two different types of food. A comparison is made between the data usually utilized in hatcheries for defining the spawning quality (number of viable eggs, fertilization and hatching rates, number of larvae produced) and the highly unsaturated fatty acid (HUFA) content of fertilized eggs at the two-cell stage. The results indicate that there is no correlation between the HUFA content of the eggs and any of the egg quality criteria examined. Nevertheless, significant differences (p<0,05) are found between the females fed with fresh trash fish (higher 18:3n-3, 20:4n-6,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Scophthalmus maximus (Linneaus; 1758). |
Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2591 |
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Coutteau, P.; Lavens, P.; Sorgeloos, P.. |
In this study baker's yeast was evaluated as a substitute for live <i>Dunaliella tertiolecta</i> algae in the culture of the brine shrimp <i>Artemia</i> . Consumption of fresh baker's yeast resulted in poor growth and survival of brine shrimp. However, the nutritional value of the yeast significantly improved after complete removal of the yeast cell wall by enzymatic treatment. Baker's yeast was also made digestible for <i>Artemia</i> by simple chemical treatment which did not reduce rigidity of the yeast cell. The external mannoprotein layer of the yeast cell wall is probably the major barrier to digestion by <i>Artemia</i> . Chemically treated baker's yeast offers promising possibilities as a substitute for... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diets; Yeasts; Artemia; Saccharomyces cerevisiae. |
Ano: 1990 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3064 |
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Coutteau, P.; Lavens, P.. |
Aquaculture is becoming more and more an industrial practice. However, feed cost, which may mount up to around 30% of the total operating costs still appears to be one of the major constraints for further expansion of aquaculture. Due to the relatively inexpensive mass-production of yeasts, serious efforts have been made to evaluate the incorporation of these Single-Cell Proteins in aquaculture diets. The aim of this communication is to review the most important results obtained with yeast diets in the different fields of aquaculture. Several authors have reported on the utilization of yeast in fish feeds. Successful incorporation of yeast into fish diets allows replacement of 25-50% of the fish meal component. Because of their small particle size yeasts... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1989 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3008 |
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Merchie, G.; Lavens, P.; Verreth, J.; Ollevier, F.P.; Nelis, H.; De Leenheer, A.P.; Storch, V.; Sorgeloos, P.. |
The effect of three dietary ascorbic acid (AA) concentrations, each applied via two feed types, on production characteristics and physiological condition of African catfish (<i>Clarius gariepinus</i>) larvae has been assessed in two 10-day culture trials. Three treatments received only <i>Artemia</i> nauplii enriched with an experimental emulsion containing 0, 10 or 20% ascorbyl palmitate (AP) and yielding 530, 1200 and 1600 µg AA g<sup>-1</sup> DW <i>Artemia</i> , respectively; the other three treatments were fed the same <i>Artemia</i> diets which were partially substituted by an artificial diet containing no vitamin C (ratio 20:80). No differences in survival could be observed: however, from... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish larvae; Food organisms; Vitamin C; Clarias gariepinus. |
Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2963 |
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Dhert, P.; Bombeo, R.; Lavens, P.; Sorgeloos, P.. |
A simple semi flow-through <i>Artemia</i> culture unit is described for possible integration in marine fish and shellfish hatcheries as a source of a cheap nursery diet. The system does not require the use of feeding pumps and involves minimal care. Food preparation and addition to the feeding tank is reduced to one or two manipulations per day during the meta-nauplius stages (day 1-3) and the juvenile stages (day 4-14), respectively. Biomass productions are superior to those reported to those for stagnant culture systems and are comparable to those demonstrated for flow-through culture units. This simple rearing technique offers the possibility of producing brine shrimp populations with a uniform size. Furthermore, by varying the feeding... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2755 |
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Merchie, G.; Lavens, P.; Dhert, Ph.; Garcia Ulloa Gómez, M.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
The effect of the high ascorbic acid (AA) levels transferred through enriched live food was evaluated for turbot <i>Scophthalmus maximus</i> larvae in two consecutive feeding experiments. The same feeding strategy was applied to all treatments, except for the AA content in the live food which was manipulated through bioencapsulation with ascorbyl palmitate. This resulted finally in a low, medium and high-AA treatment. The AA incorporation levels in the turbot larvae (up to 1400 µg AA g DW<sup>-1</sup>) were correlated with the AA content of the live food administered. However, feeding the high AA concentration resulted in the same values as for the medium treatment, indicating a saturation of the body AA reserves. Under standard... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3022 |
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Huo, J.-Z.; Nelis, H.; Lavens, P.; Sorgeloos, P.; De Leenheer, A.P.. |
In aquaculture, alpha-tocopheryl acetate (alpha-TA) is the main source of vitamin E used to fortify fish feed. Alpha-TA in fish is often determined indirectly, i.e. by alkaline hydrolysis, followed by quantitation of ‘total alpha-tocopherol’ (alpha-T) and substraction of the natively present alpha-T. The aim of this study was to develop an HPLC method for the simultaneous quantitative determination of alpha-TA and free tocopherols in aquatic organisms and fish feed. The assay consists of a simple extraction with methanol containing butylhydroxytoluene (BHT) as an antioxidant, followed by reversed-phase chromatography with consecutive UV and fluorescence detection of alpha-TA and tocopherols, respectively. The peak of the internal standard tocol in the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vitamin E; Vitamins. |
Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=4020 |
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Registros recuperados: 79 | |
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