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| Registros recuperados: 107 | |
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| Vranken, G.; Thielemans, L.K.; Heip, C.H.R.; Vandycke, M.. |
| <i>Monhystera parelegantula</i> (De Coninck,1943) was collected from the sediment of the Sluice-dock, a euhaline-polyhaline lagoon near the harbour of Ostend (Belgium). The species was cultivated in large numbers on a bacto-agar medium with bacterial growth. Embryonic growth was studied at 30 °C and 30 promille S. Maximum embryonic length-growth occurs at the vermiform stage. Post-embryonic length-growth, studied at 25 °C and 30 promille S, is a linear function of time and may be expressed as l = 160.46 + 29.55(t-t<sub>o</sub>), where t<sub>o</sub> = time at the beginning of development; t and l = time (d) and length (µm). At 25 °C and 30 promille S, average embryonic development time and generation time are 4 and 9 d... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Life cycle Monhystrella parelegantula ANE; Belgium; Oostende Harbour; Sluice Dock. |
| Ano: 1981 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3410 |
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| Soetaert, K.; Heip, C.H.R.; Vincx, M.. |
| The diversity of the nematode assemblages along a Mediterranean transect off Calvi, Corsica, Mediterranean Sea (depth range 160 to 1220 m) was very high. There was no clear trend in species diversity with station depth, and diversity at the station located on the continental shelf was not markedly lower than that at the deep-sea stations. However, diversity decreased with increasing depth into the sediment. As with the macrofauna, nematode assemblages in the Mediterranean is explained by a slight dominance of some species, while no species are dominant in the Bay of Biscay. Generic (between-genus) diversity was much higher than the average species diversity within genera, indicating that the high overall species diversity was not caused by large numbers of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1991 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2892 |
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| Vanaverbeke, J.; Soetaert, K.; Heip, C.H.R.; Vanreusel, A.. |
| The metazoan meiobenthos along the continental slope of the Goban Spur (NE Atlantic) was studied in the framework of the OMEX-programme (EC-MAST II). Meiobenthic densities, the vertical distribution of the meiobenthos in the sediment, and the biomass and generic composition of the dominant group, the nematodes, were investigated at different water depths. The meiobenthic communities along the depth gradient of the continental slope followed the usual trends: the communities were dominated by nematodes, and meiobenthic densities, total nematode biomass, and mean individual nematode weight decreased with increasing water depth. The shelf station had significantly higher densities, nematode biomass and mean individual weight than the deeper stations. The... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=5650 |
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| Vranken, G.; Vanderhaeghen, R.; Van Brussel, D.; Heip, C.H.R.; Hermans, D.. |
| The influence of the mercury compounds Hg<sub>2</sub>Cl<sub>2</sub>, HgCl<sub>2</sub>, and CH<sub>3</sub>HgCl as measured by egg mortality, preadult mortality, and development time, was studied on the marine nematode <i>Monhystera disjuncta</i>. A significant influence on egg, juvenile, and preadult mortality was observed for Hg<sub>2</sub>Cl<sub>2</sub> and HgCl<sub>2</sub>, while CH<sub>3</sub>HgCl did not cause egg mortality. It was concluded that the juvenile mortality is the most sensitive index for the chronic stress. No apparent changes in the development time occurred. The acute toxicity of the above mentioned mercury compounds, measured as... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mercury; Toxicity; Monhystera disjuncta. |
| Ano: 1984 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3277 |
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| Vranken, G.; Van Brussel, D.; Vanderhaeghen, R.; Heip, C.H.R.. |
| The brackish-water nematodes <i>Monhystera disjuncta</i> and <i>Monhystera microphtalma</i> were chosen as test organisms for ecotoxicological studies. Both species are locally abundant, have short life cycles and can be maintained for several generations under laboratory conditions. They reproduce very well on a sloppy bacto-agar (0.5-0.8%) made up with water of the natural habitat, enriched with 1% Vlasblom medium (Vlasblom, pers. commun.) and 1% silicium (15g.l<sup>-1</sup>), reaching densities of approximately 1000 individuals.cm<sup>-2</sup>. Starting from such agnotobiotic cultures, a chemically defined artificial medium has been developed. This medium consists of 0.5% bacto-agar in artificial seawater,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Toxicity tests Monhystera disjuncta Monhystera microphtalma de Man; 1880. |
| Ano: 1984 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3276 |
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| Heip, C.H.R.; Smol, N.; Hautekiet, W.. |
| The extraction of nematodes and harpacticoid copepods from muddy sediments or sediments containing a large amount of organic detritus can be achieved through a series of centrifugations of the material in a sacharose solution of at least 900 g/l. The number of individuals appearing in the supernatant after each centrifugation forms a geometric series, with a ratio which is dependent on the amount of material, the concentration of the saccharose solution, and the acceleration of the centrifuge. Knowledge of this ratio allows an estimation of density after only one centrifugation. More than 90 % of the animals present in the sample can be extracted after only two centrifugations. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1974 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3492 |
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| Vranken, G.; Heip, C.H.R.. |
| Toxicity of copper, lead and mercury to the nematode <i>Diplolaimella</i> spec 1 is studied. Mortality responses obtained demonstrate high resistance to heavy metals. Population growth parameters as the intrinsic rate of natural increase and net-reproductivity are significantly depressed at copper-concentrations which cause no juvenile mortality. The lowest concentrations tested caused significant inhibition of development rate in both sexes. For this particular nematode species suppression of fecundity and developmental inhibition are more reliable criteria, determining non-exceedable limits with regard to environmental safety. Our tests show that nematode productivity may be significantly depressed at copper levels found in some areas of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Copper; Lead; Mercury; Toxicity; Nematoda [Nematodes]. |
| Ano: 1986 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3250 |
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| Heip, C.H.R.; Smol, N.. |
| The predator-prey system between the polyp <i>Protohydra leuckarti</i> and the harpacticoid copepod <i>Tachidius discipes</i> is investigated using the results of a 3 year field survey and laboratory experiments involving the cultivation of the species. In the field a close relationship between numbers of predator and prey was observed. The possible influence of environmental factors on this relationship is discussed. A number of mathematical models is compared to investigate the possibility of realistic description of the system. It is concluded that, even during relatively long time intervals, the number of prey can be predicted from the reproductive potential of the prey on the one hand and the rate of predation and predator... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1976 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3534 |
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| Registros recuperados: 107 | |
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