|
|
|
| Registros recuperados: 87 | |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
| Deslous-paoli, Jean-marc; Heral, Maurice; Berthome, Jean-paul; Razet, Daniel; Garnier, Jacqueline. |
| In summer 1979, the natural reproduction of oysters Crassostrea gigas Thunberg, in Marennes-Oleron basin, produced a large number of juveniles which was not the case in summer 1981. If one compares the evolution of the main constituents of the flesh, one can see that, at the beginning of August, before spawning the male oysters in 1981 contained 6,3% less proteins, 34,2% less lipids and 61,2% less glucids than those in 1979 and respectively 12,3%, 21,3% and 69,8% less as far as females are concerned. The energetic value of ash-free dry flesh of female oysters is nearly the same for the two years whereas for male oysters the value is slightly lower in 1981 than in 1979. The total energetic values of male and female oysters show a slight difference between... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Seasonal variations; Food availability; Water temperature; Saccharides; Proteins; Lipids; Biochemical composition; Gametogenesis; Spawning; Sexual reproduction. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-1891.pdf |
| |
|
| |
|
|
| Chopin, T; Floc'H, J; Bodeau, B; Penot, M. |
| Phosphorated nutrition of the red alga Chondrus crispus Stackh. is studied is two morphologically very dissimilar forms of the thallus. Phosphorus measurements, which were monthly carried out at different parts of the alga, showed first that the distribution of this element is not homogeneous along the thallus, and second that seasonal variations occur. It is suggested that the classical polymorphism of the species can be taken into account as concerns its physiology. Besides, from absorption and exsorption experiments which were performed with super(32)P as a tracer, it is shown that the high concentration factor of phosphorus in the alga as compared to the environmental seawater (up to 17.9 x 10 super(4)) can be explained as an effect of metabolic process. |
| Tipo: Text |
Palavras-chave: Chondrus crispus; Algae; Distribution; Metabolism; Seasonal variations; Food absorption; Phosphorus; Plant nutrition. |
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/1983/acte-1175.pdf |
| |
|
| |
|
| |
|
| |
|
|
| Gaudy, R; Pagano, M. |
| The zooplankton of an eutrophic brackish lagoon (Etang de Berre), near Marseille (France) was studied during an annual cycle. It was characterized by large populations of a pelagic copepod (Acartia tonsa ). Grazing on natural particles by this species was investigated. Adults were able to use an extended range of particle sizes, but showed selectivity for particles concentration was observed (14 mu m). Temperature and particles concentration appear to modify the selectivity behavior. Juvenile stages could also catch particles of various size but did not show the same selectivity for the peak particles as adults. Daily food ration was high comparatively to open-sea copepods. Taking into account several results obtained on food ration, egg production and... |
| Tipo: Text |
Palavras-chave: Copepoda; Lagoons; Energy budget; Seasonal variations; Particle concentration; Zooplankton; Food availability; Temperature effects; Nutrition. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1526.pdf |
| |
|
|
| Plantecuny, M; Bodoy, Alain. |
| In order to estimate energetic relationship, microphytic and benthic bivalve levels of a shallow (1.5 m), sandy ecosystem near Marseille (Gulf of Fos, Southern France) were sampled monthly during 1.5 year, in two sites differing by their wave exposure. In the sheltered area, the bivalve Ruditapes decussatus was the dominant species, while another bivalve, Donax trunculus , was found in the open, wave exposed site. Chlorophyll a and primary production of the phytoplankton and the microphytobenthos, as well as population dynamic, growth and biochemical composition of bivalves (lipids, proteins and carbohydrates) were monitored. |
| Tipo: Text |
Palavras-chave: Ruditapes decussatus; Bivalvia; Periphyton; Phytoplankton; Biochemical composition; Growth; Marine molluscs; Hydrodynamics; Seasonal variations; Primary production; Trophic relationships. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1528.pdf |
| |
|
|
| Hoppe, H. |
| Extracellular enzymes mediate the decomposition of polymeric organic compounds in natural waters. In many cases these enzymes comprise a component linked to the bacterial fraction of the aquatic community and react in close association with these cells. An annual survey of microbial activities in a brackish water fjord exhibited an excellent correlation between V sub(m) of proteases (ability to split the substrate analogue methylumbelliferyl-leucine) and V sub(m) as well as T sub(R) for leucine uptake by microorganisms. Hydrolysis rates (H sub(R)) for the decomposition of naturally occurring competitive substrate analogues of the model substrates (methylumbelliferyl-(MUF)-leucine, MUF- alpha -D-glucose, MUF-N-acetyl-glucosamine, MUF-phosphate) drastically... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Fjords; Bacteria; Brackishwater environment; Seasonal variations; Dissolved organic matter; Interspecific relationships; Hydrolysis; Enzymes. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-952.pdf |
| |
|
|
| Caumette, P. |
| In the deepest parts of the estuarine region of Ebrie Lagoon (Abidjan Africa, (5 degree N, 4 degree W) stratified conditions have been observed during the rainy season (May to Nov.), owing to salinity differences between oxic and anoxic layers. At the interface, 3-4 m depth, phototrophic bacteria (Chromatium, Chlorobium and Pelodictyon ) developed, forming a brown layer due to their different pigments. Their production has been estimated at 41% of the total photosynthetic production during high stratification (Sep. 1981) and their biomass was used by the copepod population for 40 to 60% of its diet. During the dry season, the water column became homogeneous and oxygen was detected to 6m depth. The brown layer of phototrophic bacteria disappeared, as well... |
| Tipo: Text |
Palavras-chave: Chlorobium; Chromatium; Primary production; Photosynthesis; Estuaries; Seasonal variations; Plankton; Stratification; Vertical distribution; Bacteria; Coastal lagoons; Trophic relationships; Biomass. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-957.pdf |
| |
|
| |
|
|
| Herbert, R. |
| Seasonal data and depth profiles using super(15)N-labelled NO sub(3)u- show that denitrification (77-90% of NO sub(3)u- respired) rather than NO sub(3)u- dissimilation to NH sub(4)u+ was the principal route of nitrate reduction in Kingoodie Bay sediments. Populations of both groups of NO sub(3)u- reducing bacteria were highest in the 0-20 mm horizon in those sediments where highest rates of NO sub(3)u- respiration were recorded (28.56 mu g N.d super(-1) dry wt. sediment super(-1)). Autotrophic nitrification rates shared a marked seasonality with highest rates (0.92 mu g N.d super(-1).g dry wt. sediment super(-1)) occurring during the summer. Maximum populations of autotrophic nitrifying bacteria were also found in the 0-20 mm sediment horizon and these... |
| Tipo: Text |
Palavras-chave: Seasonal variations; Bacteria; Estuaries; Sediment chemistry; Biogeochemistry; Ammonia; Nitrates; Nitrogen cycle. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-971.pdf |
| |
|
|
| Lakshmanaperumalsamy, P; Chandramohan, D; Natarajan, R. |
| A seasonal study on the occurrence and distribution of total aerobic microbial population (TMP), total aerobic heterotrophic bacteria (THB), actinomycetes and fungi in the sediments of Vellar Estuary, South India (11 degree 29'N 79 degree 46'E) was carried out during Jan. to Dec. 1975. Sediment samples were collected at monthly intervals, from 4 stations and analysed microbiologically. In general, bacterial population was found to be dominant followed by actinomycetes and fungi. The max peak for TMP, THB and fungi were recorded in Nov. in all stations. Monsoon season supported TMP, THB and fungi to a high level and it was summer for actinomycetes. Statistical analysis (Kendall's tau) showed a significantly positive correlation among TMP, THB, actinomycetes... |
| Tipo: Text |
Palavras-chave: Actinomycetes; Population number; Statistical analysis; Seasonal variations; Fungi; Bacteria; Sediment analysis; Microbiological analysis. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-943.pdf |
| |
|
| |
| Registros recuperados: 87 | |
|
|
|
