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| Registros recuperados: 1.500 | |
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| Heip, C.H.R.; Engels, P.. |
| The segregation along the horizontal space dimension of the niche has been investigated in six copepod species occurring together in a brackish water habitat.All but one species show an aggregated pattern which may be described by a negative binomial distribution. The aggregations are small with a radius of 5-15 cm and are distributed randomly in the habitat. Aggregation of different species do not overlap; niche-overlap in this dimension show a somewhat wider utilization of space by the dominant species and insignificant overlap between species; there was no competition for space at the time of the investigation. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1977 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3561 |
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| De Pauw, N.. |
| The nutritional value of various foods and diets for juvenile bivalves is reviewed and commented. From all foods tested specific microalgues seem to be the most suited for young bivalves. Presently, serious alternatives for replacing living algae by inert, artificial feeds are practically inexistent, though research efforts are made in this direction. The various microalgae production-systems used for feeding juvenile bivalves are also reviewed. A literature survey and the COST inquiry held in 1979 by our laboratory revealed that nearly all commercial enterprises involved in nursery rearing of bivalve molluscs in Europe utilize natural phytoplankton as food. Culturing of the postlarvae is performed either <i>in situ</i> (in the sea) or in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Algae culture; Food; Mollusc culture; Bivalvia. |
| Ano: 1981 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3406 |
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| Joiris, C.R.; Tapia, G.; Holsbeek, L.. |
| Beached seabirds, mainly common guillemots Uria aalge, were collected on the Belgian coast during winter from 1990 to 1995. Concentrations of total and organic mercury, and of organochlorines (PCBs and pesticides) were determined in muscle, liver and kidney. They were high compared to summer data (up to one order of magnitude), and increased during winter. This increase is not due to changes of total body weight nor polar lipid content, and thus reflects an actual increase of the seabirds' contamination while wintering in the southern North Sea. The observed annual cycle can be understood by assuming differences in prey contamination: higher during winter in the southern North Sea ecosystem than during summer in the Atlantic water ecosystem. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6846 |
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| De Vocht, A.J.-P.. |
| The ultrastructural organization of the proboscis in two species of free-living Platyhelminthes, <i>Psammorhynchus tubulipenis</i> and <i>Cytocystis clitellatus</i> is very alike but differs from previously described species. Both sheath and cone epithelium are composed of two circumferential belts. Only the basal cone epithelium is syncytial, while no nuclei were found in the distal belt of the sheath epithelium. The sheath epithelium is characterized by numerous infoldings of the basal plasma membrane. The nuclei present in the bulb belong to the proximal belt of the sheath epithelium and the apical cone epithelium. Nuclei of the basal cone epithelium are located insunk behind the proboscis bulb. The insunk cell parts pierce the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ultrastructure Cytocystis clitellatus Psammorrynchus tubulipenis Meixner; 1938. |
| Ano: 1990 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3078 |
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| Kolaitis, L.N.; Bruynseels, F.; Van Grieken, R.; Andreae, M.O.. |
| In open ocean waters the predominant volatile sulfur compound is dimethyl sulfide (DMS), representing almost 90% of the marine sulfur emissions. Methanesulfonic acid (MSA), one of the oxidation products of DMS, is consequently an important constituent of marine aerosols. Laser microprobe mass analysis (LAMMA) has been used for single-particle analysis of particles collected in the marine boundary layer. MSA, like the non-sea-salt sulfate, is mainly associated with the smallest aerosol particles, whose LAMMA spectra match the reference fingerprint spectra of MSA salts, sodium methanesulfonate and ammonium methanesulfonate. The presence of nitrate and heavy metal ions in the LAMMA spectra can reveal, to a certain extent, the degree of air pollution at the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols; Air pollution; Boundary layers; Heavy metals; Marine environment; Nitrates; Particle size; Sulphates. |
| Ano: 1989 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3177 |
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| Coutteau, P.; Geurden, I.; Camara, M.R.; Bergot, P.; Sorgeloos, P.. |
| A beneficial effect of dietary phospholipid (PL) supplementation in purified diets in terms of survival, growth, resistance to stress tests, and occurrence of deformities has been demonstrated in larval and juvenile stages of various species of fish and crustaceans. The exact determination of PL requirements in larvae is complicated due to the difficulty to bio-encapsulate PL in live prey. Furthermore, the great variety in purity and composition of the PL sources, and the experimental conditions (such as diet formulation and extent of co/prefeeding with live food) makes it difficult to compare requirements determined with artificial diets. Larval stages are extremely sensitive to a dietary PL deficiency and require higher levels of dietary PL than... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Complex lipids; Crustacean culture; Crustacean larvae; Diets; Fish culture; Fish larvae. |
| Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2927 |
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| Redant, F.. |
| Bivalves and gastropods landed in Belgium are taken as a by-catch of fisheries targeting finfish or crustaceans, and the nation has never had specialized molluscan fisheries. Species landed consist mainly of whelk, <i>Buccinum undatum</i>; and scallops, <i>Pecten maximus</i> and <i>Chlamys</i> spp. Long-term trends in the landings of mollusks are closely related to long-term changes in fleet and vessel size, gear types used, fishing grounds and target species, and demand on the local market. In the 1950' s, the annual landings of whelk fluctuated between 80 and 200 t, while those of scallop were insubstantial. Since then, the landings gradually rose to record figures of 678 t for whelk and 762 t for scallop in the... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1997 |
URL: http://www.vliz.be/imisdocs/publications/267114.pdf |
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| Hecq, J.H.. |
| The annual cycle of the Copepods, Cladocera, Appendicularians, Chaetognatha and Cnidaria has been observed in a coastal area in front of Boulogne-sur-Mer. Four species of Copepods amount to some 70% of the whole zooplankton. These herbivorous animals become especially abundant during the phytoplankton blooms with yield which seems to be more important during the autumn than during the spring. Yearly the Appendicularians offer four maxima agreeing with the transport of patches by the currents. The Chaetognatha are only present during the autumn. The cycle of Cladocera is described with respect to their fecundity. The Ctenaria show blooms succeeding those of herbivorous animals. The study of relations between the zooplankton trophic levels suggests that, in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Annual variations Zooplankton ANE; France; Nord; Boulogne-sur-Mer. |
| Ano: 1976 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3548 |
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| Registros recuperados: 1.500 | |
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