Consulta: subjectFacets:"Urée"
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Data/hora: 13/06/2024 15:21:24

Comparison of brown trout (Salmo trutta) reared in fresh water and sea water to freshwater rainbow trout (Oncorhynchus mykiss) .1. Growth and nitrogen balance
Provedor de dados: 5
Autores: Dosdat, Antoine; Metailler, Robert; Desbruyeres, Elisabeth; Huelvan, Christine.
Brown trout and rainbow trout (average weight 100 g) were reared in fresh water at 12 degrees C under the same conditions before transfer of brown trout to sea water, in order to compare nitrogen utilisation in the two species. Apparent protein digestibility (ADC), nitrogen (ammonia and urea) excretion, protein productive value (PPV) and actual observed nitro en mass balance were determined. Rainbow trout raised in fresh water had a higher growth rate (1.1 vs 0.8%. d(-1)), better food conversion ratio (0.7 vs 1.0), better ADC (91 vs 85%) and PPV (45 vs 35%) and lower ammonia excretion rates than brown trout reared in fresh water. Transferring brown trout to sea water induced lower PPV (30%) and ammonia and urea excretion. Salinity did not modify metabolic...
Tipo: Text
Palavras-chave: Truite commune; Truite arc-en-ciel; Excrétion; Ammoniaque; Urée; Digestibilité; Croissance; Rétention protéique; Rainbow trout; Brown trout; Excretion; Ammonia; Urea; Digestibility; Growth; Protein productive value.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00188/29885/28342.pdf

Paramétrisation de la nutrition azotée et phosphorée d'Alexandrium catenella, microalgue toxique responsable d'efflorescences dans la lagune de Thau
Provedor de dados: 5
Autores: Jauzein, Cecile.
In the Thau lagoon, blooms of the toxic microalgae Alexandrium catenella have induced regular losses of shellfish production since 1998 due to bioaccumulation of toxins in oysters and mussels. This thesis was conducted to enhance knowledge of toxic bloom development regulation by environmental factors, focusing on nitrogen and phosphorus nutrients influence on A. catenella growth. These works highlighted a large variety of potential nutritive sources for this species and a major part of these nutrients appeared to be potentially regenerated in the water column. Different organic sources may contribute to the growth of A. catenella from diverse nutrition processes: direct absorption through the cell membrane (for urea), enzymatic degradation in the...
Tipo: Text
Palavras-chave: Alkaline phosphatases; Mixotrophy; Phosphate; Urea; Ammonium; Uptake kinetics; Alexandrium catenella; Phosphatases alcalines; Mixotrophie; Phosphate; Urée; Ammonium; Cinétiques d'absorption; Alexandrium catenella.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/these-6511.pdf

Effects on phytoplankton growth of dissolved substances produced by fish farming
Provedor de dados: 5
Autores: Arzul, Genevieve; Clement, Alejandro; Pinier, Anne.
Fish Farming enriches the water column in dissolved organic and inorganic material. These materials excreed by the fish, elutriate from uneaten food and derive from other polluting substances. Ratios of the organic/inorganic forms of substances (for example N and P) are thus modified. Such perturbations in turn affect phytoplankton development. From in vitro analyses and tests of water taken from a turbot rearing tank, we show the changes in seawater chemical composition produced as well as the way growth was modified in three phytoplankton species: the diatom, Chaetoceros gracile, and the dinoflagellates, Gymnodinium cf. nagasakiense and Alexandrium minutum. Elutriates from the granules used for feed (0.1 to 100 mg.l(-1)) were found to be stimulating,...
Tipo: Text
Palavras-chave: Antibiotique; Fécès; Aliment; Aquaculture; Régulation de croissance; Phytoplancton; Urée; Antibiotic; Faeces; Feed; Fish farming; Growth regulation; Phytoplankton; Urea.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00188/29887/28340.pdf