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| Registros recuperados: 79 | |
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| Vanhaecke, P.; Lavens, P.; Sorgeloos, P.. |
| Variations in dry weight, caloric content and ash content during cyst hatching and early larval development have been studied for various geographical strains of <i>Artemia</i> . In general, decapsulated cysts contain 30 to 40% more energy than freshly hatched nauplii; for Chaplin Lake and Buenos Aires <i>Artemia</i> this difference amounts to 57%. Ash contents increase as decapsulated cysts hatch into instar I and molt into instar II-III nauplii. Over a 24h larval developmental period individual dry weights and energy content of the nauplii decrease with 16-34% and 22-37% respectively.A small but significant correlation exists between the survival rate of starved nauplii and either the energy content of instar I and instar II-III... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cysts; Energy budget; Larval stages; Artemia. |
| Ano: 1983 |
URL: http://www.vliz.be/imisdocs/publications/261926.pdf |
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| Wouters, R.; Van Hauwaert, A.; Naessens, E.; Ramos, X.; Pedrazzoli, A.; Lavens, P.. |
| The influence of varying dietary n-3 HUFA concentrations and ratios of 22:6n-3/20:5n-3 (DHA/EPA) on culture performance and fatty acid composition of white shrimp (<i>Penaeus vannamei</i>) larvae and postlarvae was verified in two experiments. In a first experiment, shrimp (zoea 2-postlarvae 11) were fed rotifers (<i>Brachionus plicatilis</i>) and <i>Artemia</i> spp. nauplii that were enriched with different self-emulsifying concentrates: one HUFA-free coconut oil (T1), and three iso-HUFA concentrates with DHA/EPA ratios of 0.6 (T2), 2 (T3) and 4 (T4), respectively. In a second experiment, postlarvae were fed for 25 days (starting from postlarvae 10) on isolipidic semi-purified diets: one HUFA-free control (TA), and four... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2987 |
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| Lavens, P.; Sorgeloos, P.. |
| It is generally accepted, that a major constraint in the further development of marine fish and crustacean aquaculture, is the variable quality of eggs and larvae used for the hatchery-production of fry. Nonetheless, valid criteria to evaluate optimal egg quality have not been identified yet. Instead, particular indicators, are used, e.g. the fertilization and hatching rate, overall culture success during the first rearing period, etc., but these are not totally objective because hatchery-specific conditions may interfere. The biochemical composition of the egg may be one of the possible determinants of egg quality, which can be evaluated on a more objectie basis. In this respect, studied have been initiated to analyze in freshly-released eggs, the levels... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aquaculture techniques; Biochemical composition; Crustacean culture; Eggs; Fatty acids; Fish culture; Hatcheries; Quality control; Vitamin C. |
| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262328.pdf |
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| Van Stappen, G.; Lavens, P.; Sorgeloos, P.. |
| Short-term treatment with peroxide solutions has been tested as a chemical way to break the diapause of <i>Artemia</i> cysts of different species and geographical strains. The methodology was further standardized by analyzing the impact of the cyst hydration level and the application conditions (concentration, duration, temperature) on the hatching percentage. The peroxide treatment was most effective in deactivating diapause when applied on fully hydrated cysts, and showed a quantitative nature: a maximal positive effect was obtained for specific combinations of peroxide concentration and exposure time. The peroxide effect was preserved after processing and storage of treated cysts. The biochemical mechanisms possibly involved in induction and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=321 |
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| Dhert, P.; Lim, L.C.; Lavens, P.; Chao, T.M.; Chou, R.; Sorgeloos, P.. |
| In spite of its aquaculture potential, the larval rearing of greasy grouper (<i>Epinephelus tauvina</i>) remains problematic and is not yet commercially feasible. The low and unpredictable larval survival is due to difficulties encountered in spawning the broodstock, the small size of the larvae at first feeding, and the high sensitivity of the larvae until day 45. The nutritional requirements for the broodstock as well as for the young larvae are still enigmatical. In this presentation the impact of supplementing the highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA) to the broodstock and larval diets is illustrated. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diets; Fatty acids; Fish culture; Fish eggs; Fish larvae; Nutritional requirements; Survival. |
| Ano: 1991 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2852 |
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| Merchie, G.; Lavens, P.; Dhert, Ph.; Dehasque, M.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| Ascorbic acid (AA) is an essential nutrient in particle and live aquafeeds. In order to better assess the needs for this nutrient during larviculture the AA content of algae, rotifers and <i>Artemia</i> was studied with respect to their suitability at startfeeding. In general, the microalgae evaluated were rich in AA (1000-4000 µgAA/gDW), but showed a considerable variability among the different species: e.g. the concentration in <i>Isochrysis</i> and<i>Chlorella</i> reached values 3-to 4-fold the percentage of <i>Tetraselmis</i> (0.11% of DW). <i>Brachionus</i> routinely cultured on <i>Chlorella</i> contained 2300 µg AA/gDW. Cysts of various batches and strains of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2578 |
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| Merchie, G.; Lavens, P.; Sorgeloos, P.. |
| In order to assess the dietary needs for ascorbic acid (AA) at startfeeding, the AA content in the various live diets currently applied in aquaculture (algae, rotifers, <i>Artemia</i> ) was studied. Application of boosting techniques using ascorbyl palmitate (AP) as the vitamin C source enabled the transfer of elevated levels of bioactive vitamin C (up to 2500µg AA.g DW<sup>-1</sup>) via the live food chain into larvae of fish (<i>Clarias gariepinus, Dicentrarchus labrax, Scophthalmus maximus</i>), shrimp (<i>Pennaeus vannamei</i>) and prawn (<i>Macrobrachium rosenbergii</i>). This vitamin C enrichment procedure has proven to be a valuable technique, especially for the evaluation of the effects of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2587 |
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| Cavalli, R.O.; Tamtin, M.; Lavens, P.; Sorgeloos, P.. |
| This study describes the variations in total lipid, lipid classes and fatty acids in the midgut gland (MG), ovary, and muscle tissue of wild-caught <i>Macrobrachium rosenbergii</i> to elucidate the importance of these components during sexual maturation. Mature females were captured in the Mae Klong River, Thailand, from July to September 1998, and divided into five groups according to their ovarian development. Total lipid levels in the ovary increased with maturation, but no concomitant decrease in MG lipids was observed. Thus, the lipid requirements of the developing ovary are thought to be more dependent on the immediate ingestion of dietary lipid than on MG reserves. Higher proportions of neutral lipids (NL), mainly triacylglycerols (TG),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biochemical composition; Fatty acids; Lipids; Muscles; Natural populations; Ovaries; Polyunsaturated fatty acids; Prawn culture; Sexual maturity; Macrobrachium rosenbergii; Thailand. |
| Ano: 2001 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6923 |
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| Merchie, G.; Lavens, P.; Radull, J.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| The effects of high levels of ascorbic acid (AA) delivered through enriched live food has been verified through the successful culture of larval giant freshwater prawn, <i>Macrobrachium rosenbergii</i> Two successive feeding trials were set up using a control (550 µg AA g<sup>-1</sup> DW) and two different AA-enrichment levels in <i>Artemia</i> (1300 and 2750 µg AA g<sup>-1</sup> DW). Under standard culture conditions, no differences in growth nor survival could be observed demonstrating that the nutritional requirements are below 550 µg AA g<sup>-1</sup> DW, which is the normal level occurring in freshly-hatched <i>Artemia</i> . However, a significantly positive effect could be... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2582 |
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| Dhert, Ph.; Lavens, P.; Dehasque, M.; Sorgeloos, P.. |
| The rotifer feeding regime for larval turbot could be improved by more regular feeding and adjusted food distributions as to prevent overfeeding and digestion problems. All tests were successfully run in clear-water conditions indicating that the administration of algae is not essential during the rotifer stage. Larval requirements with respect to (n-3) RUFA, and more specifically DRA and DRA/EPA ratio appeared to change according to the age of the larvae and the physiological condition at the different larval stages. As early as the first week the stress resistance of the larvae could be improved by feeding rotifers specifically enriched in DRA. However, the continuous feeding of these live preys did not result in the best larval output, indicating that... |
| 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=2553 |
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| Registros recuperados: 79 | |
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