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Registros recuperados: 17
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A model of nematode dynamics in the Westerschelde Estuary OMA
Li, J.; Vincx, M.; Herman, P.M.J..
We developed a time dynamic model to investigate the temporal dynamics of nematode community in the brackish zone of the Westerschelde Estuary. The biomass of four nematode feeding groups observed from March 1991 to February 1992 is used to calibrate the model. Using environmental data as the input, the model predicts the temporal modification and interrelation of four nematode feeding groups. Nematodes achieve a dominant position in the community because of their lower loss rate (in respiration, excretion and natural death). Predators which are deposit-feeding macrobenthos control the variations of dominant nematodes, such as omnivores and non-selective deposit feeders. Food availability causes modification only for rare nematodes such as epigrowth...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Diatoms; Ecology; Food; Light; Marine nematodes; Meiobenthos; Population dynamics; Predation; Respiration; Temperature; Nematoda [Nematodes].
Ano: 1996 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7284
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A re-evaluation of marine nematode productivity OMA
Vranken, G.; Herman, P.M.J.; Vincx, M.; Heip, C.H.R..
Nematodes are the most abundant multicellular animals in marine sediments but their role in the benthos has not been properly quantified yet. In nearly all energy-flow budgets of marine systems their annual production P is given as about nine times their biomass B and their part in the total energy-flow is consequently estimated as anywhere between 3 and 30% of the total (carbon) input in the benthic system. Our laboratory experiments demonstrate that nematode productivity is much higher than P/B ~ 9 per year and may reach values of over 60 for bacterial grazers. To obtain more reliable estimates for field populations we propose a regression equation relating egg-to-egg development time T<sub>min</sub> to temperature (t) and adult female weight...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Biological production; Mathematical models; Meiobenthos; Nematoda [Nematodes].
Ano: 1986 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3576
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A seasonally varying biotope at Signy Island, Antarctic: implications for meiofaunal structure OMA
Vanhove, S.; Beghyn, M.; Van Gansbeke, D.; Bullough, L.W.; Vincx, M..
Under the typical high-latitude conditions of temperature, productivity and settlement of chlorophyll and phaeophytin to the sediment, many benthic organisms in the Antarctic show strong seasonal variation. Although meiofauna comprise an important component of the southpolar benthic ecosystem, our knowledge of them is limited. The metazoan meiofauna and the surrounding sediments were studied fortnightly for 18 mo in a shallow bay at Signy Island (Factory Cove, South Orkneys, Antarctica) to test whether and how the temporal variability of the environment influenced meiobenthos dynamics. By examination of the distribution of the abundance and biomass of the total community, the density of higher taxonomic groups, and of individual dominant nematode genera...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Benthos; Biomass; Population density; Seasonal variations; Sediment analysis; Trophic relationships; Copepoda [copepods]; Nematoda [Nematodes]; Ostracoda.
Ano: 2000 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6138
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Calculation of the intrinsic rate of natural increase, r<sub>m</sub>, with <i>Rhabditis marina</i> Bastian 1865 (Nematoda) OMA
Vranken, G.; Heip, C.H.R..
The life-cycle of <i>Rhabditis marina</i> Bastian 1865 was studied at 25°C and 20 promille salinity. The following demographic parameters were computed from life-table data: the intrinsic rate of natural increase (r<sub>m</sub>) = 0.914 day; net reproductivity (R<sub>0</sub>) = 400; minimum generation time (T<sub>min</sub>) = 4.5 days; cohort generation time (T<sub>c</sub>) = 7.2 days; mean generation time (T) = 6.6 days; and the age of an adult female when a median egg is deposited (T) = 6.1 days. Several approximate equations used to estimate r<sub>m</sub> were compared with these life-table calculations. Some give erroneous estimations and should be used with extreme caution. For...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Population characteristics; Nematoda [Nematodes]; Rhabditis marina.
Ano: 1983 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3260
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<i>Polkepsilonema mombasae</i> gen. et sp. n. and <i>Pternepsilonema servaesae</i> gen. et sp. n. (Nematoda, Epsilonematidae) from East African coasts OMA
Verschelde, D.; Vincx, M..
Two new genera and species from Kenyan tidal areas, <i>Polkepsilonema mombasae</i> gen. et sp.n. and <i>Pternepsilonema servaesae</i> gen. et sp.n., are described. Both are characterized by the presence of at least fourteen subcephalic setae and by thick thorns on the ventral body region of males. In the first genus, eight to ten subcephalic setae are situated at the posterior edge of the rostrum, and the ambulatory setae are straight. A key of the 13 genera of the Epsilonematidae is presented.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Epsilonematidae; Nematoda [Nematodes]; Polkepsilonema mombasae; Pternepsilonema servaesae.
Ano: 1993 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2797
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<i>Procamacolaimus tubifer</i> Gerlach, 1953, <i>Procamacolaimus africanus</i> sp. nov. and <i>Eontolaimus capensis</i> gen.nov., sp.nov. (Nematoda, Leptolaimidae) from Southern Africa OMA
Furstenberg, J.P.; Vincx, M..
A female and three males of <i>Procamacolaimus tubifer</i> Gerlach, 1953 are described and illustrated from Cape Receife Beach, Port Elizabeth. <i<P. africanus</i> sp.nov. is also described from Cape Receife Beach. It is compared with <i>P. tubifer</i> which it resembles but from which it can be differentiated by length of the buccal cavity, amphid size and the shape of the spicules. <i>Eontolaimus capensis</i> gen.nov., sp.nov. is described, also from the same sandy beach. This new genus is related to <i>Deontolaimus papillatus</i> de Man, 1880 from which it can be distinguished, among other things, by the absence of a tooth-like structure in the buccal cavity and the presence of pre-anal tubuli.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Leptolaimidae; Nematoda [Nematodes].
Ano: 1988 URL: http://www.vliz.be/imisdocs/publications/276167.pdf
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Meiobenthos of the central Arctic Ocean with special emphasis on the nematode community structure OMA
Vanreusel, A.; Clough, L.M.; Jacobsen, K.; Ambrose, W.; Jivaluk, J.; Ryheul, V.; Herman, R.; Vincx, M..
We investigated the abundance of the meiobenthos and the biomass and community structure of the nematodes in the central Arctic Ocean along two separate transects during 1991 and 1994. Meiobenthos abundances ranged from < 100 to 600 individuals per 10 cm², in the same order of magnitude as in other oligotrophic areas of the world's deep ocean. Nematodes were the numerically dominant meiofaunal group at every station. Nematode biomass ranged from < 1 to 48 µg dry weight per 10 cm². A combination of water depth and latitude explained 55% of the variability among stations in nematode biomass and 67% of the variability of total abundance, implying that both vertical and advective fluxes are important sources of food to the meiofaunal communities. The...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Community composition; Marine invertebrates; Meiobenthos; Spatial variations; Zoobenthos; Monhystera; Nematoda [Nematodes]; Pitcairn I..
Ano: 2000 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7425
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Nematodes as indicators pollution: a case study from the Swartkops River system, South Africa OMA
Gyedu-Ababio, T.; Furstenberg, J.P.; Baird, D.J.; Vanreusel, A..
Nematodes from the sediments of the Swartkops estuary in Port Elizabeth, South Africa were investigated at 10 selected sites along a salinity gradient in the subtidal region at neap tide. The relation between nematode density, genera, community structure and environmental parameters including concentrations of seven heavy metals, Mn, Ti, Cr, Pb, Fe, Sn and Zn in the sediment were investigated. The nematode community structure was significantly influenced by the chlorophyll a concentration and sediment particle-size distribution. The number of genera had significant negative correlation with chlorophyll a and two heavy metals, Fe and Zn in the sediment. The habitat preferences of the genera were also assessed. A combination of the Shannon-Wiener Diversity...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Check lists; Density; Diversity; Ecology; Meiobenthos; Pollution; Sediment; Sediments; Nematoda [Nematodes].
Ano: 1999 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7328
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Selective attraction of marine bacterivorous nematodes to their bacterial food OMA
Moens, T.; Verbeeck, L.; de Mayer, A.; Swings, J.; Vincx, M..
This paper explores the role of selective attraction to food in determining the spatial (micro)distribution of closely related nematode species. The attractiveness of 3 different bacterial strains to 4 species of Monhysteridae, <i>Diplolaimelloides meyli, Diplolaimella dievengatensis, Monhystera</i> sp. and <i>Geomonhystera disjuncta</i>, was studied in a multiple choice design. In our study area, the 4 nematode species considered are associated with <i>Spartina anglica</i> detritus decay and have partially overlapping microhabitat preferences. As they all belong to the same feeding guild, they are potential competitors for food. Each of the 4 nematode species was attracted to the bacterial strain B1, but important...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Chemotaxis; Recruitment; Taxis; Bacteria; Diplolaimella dievengatensis; Diplolaimelloides meyli; Geomonhystera disjuncta; Nematoda [Nematodes]; Spartina anglica [common cord-grass].
Ano: 1999 URL: http://www.vliz.be/imisdocs/publications/273317.pdf
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Studies of the life-history and energetics of marine and brackish-water nematodes: 2. Production, respiration and food uptake by <i>Monhystera disjuncta</i> OMA
Herman, P.M.J.; Vranken, G..
An energy budget was constructed for the marine nematode <i>Monhystera disjuncta</i>. Respiration was measured with a modified Cartesian diver technique, in which the nematodes were kept in agar inside the diver 'head'. The relationship between respiration and body weight was: R=1.53 W<sup>0.75</sup>. Body growth was exponential during the juvenile phase, with a growth rate equal to 0.61 d<sup>-1</sup>. After maturation the growth rate fell to 0,17 d<sup>-1</sup>. Food uptake was measured in experiments with radiolabeled bacteria. In one series of experiments the accumulation of radiolabel in the nematodes was followed. In a second series the decrease in labeling was followed when pre-labeled nematodes fed on...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Bioenergetics; Brackishwater environment; Energy budget; Energy flow; Feeding; Life history; Meiobenthos; Respiration; Monhystera disjuncta; Nematoda [Nematodes].
Ano: 1988 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3146
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Temperature and salinity constraints on the life cycle of two brackish-water nematode species OMA
Moens, T.; Vincx, M..
The present study investigates the influence of salinity and temperature on the life history of two estuarine bacterivorous nematode species, <i>Pellioditis marina</i> and <i>Diplolaimelloides meyli</i>, isolated from the mesohaline zone of the Westerschelde Estuary, SW Netherlands. Gravid females and adult males were inoculated in petri dishes containing agar layers of nine (for <i>P. marina</i>) or five (for <i>D. meyli</i>) different salinities, from almost freshwater to higher than marine, and incubated at a temperature of 20°C, to study the impact of salinity; agar layers with a salinity of 20‰, incubated under each of six different temperatures from 5 to 30°C, served to study the effect of temperature....
Tipo: Info:eu-repo/semantics/article Palavras-chave: Nematoda [Nematodes].
Ano: 2000 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7421
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Temperature, salinity and food thresholds in two brackish-water bacterivorous nematode species: assessing niches from food absorption and respiration experiments OMA
Moens, T.; Vincx, M..
Respiration and food assimilation of two estuarine bacterivorous nematodes, the rhabditid <i>Pellioditis marina</i> and the monhysterid <i>Diplolaimelloides meyli</i>, were measured at a range of temperatures, salinities, and food densities. The aim of this study was to identify the fundamental niche of both species in their natural habitat, and to investigate the relative importance of food and abiotic factors in determining presence and success of nematode species in the highly dynamic estuarine tidal environments of macrophyte detrital habitats. Of the three factors studied, salinity least impacted <i>P. marina</i> and <i>D. meyli</i>. Respiration and assimilation in both species showed only minor...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Nematoda [Nematodes].
Ano: 2000 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7422
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The ecology of marine nematodes OMA
Heip, C.H.R.; Vincx, M.; Vranken, G..
Nematodes are probably the most abundant metazoans in the biosphere and of very great importance to man. As parasites of man they are responsible for disease in hundreds of millions of people and an estimated eight billion nematodes are enjoying food, warmth and shelter in human intestines today; <i>Ascaris lumbricoides</i> is, after the viruses responsible for diarrhoeal disease, the second most infectious organism in the world, about a quarter of the world's population being infected (Ash, Crompton & Keymer, 1984). Plant-parasitic nematodes cause considerable damage to crops and many species are vectors of soil-borne viruses. Today, plant nematology is one of the most vital fields in agricultural research and is studied in many university...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Ecology; Literature reviews; Nematoda [Nematodes].
Ano: 1985 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3205
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The meiofauna: macrofauna ratio across the continental slope of the Goban Spur (north-east Atlantic) OMA
Flach, E.; Vanaverbeke, J.; Heip, C.H.R..
Meio- and macrofauna density and biomass were estimated at the OMEX-transect across the continental slope of the Goban Spur at water depths ranging from 208 to 4460 m in the north-east Atlantic. A linear increase in the ratio between meio- and macrofauna densities with increasing water depth was found. At the continental shelf meiofauna densities were similar to 50 times higher than macrofauna densities, whereas in the abyss meiofauna densities were more than 1000 times higher. This change in ratio was due to a significant decrease in macrofauna densities with increasing water depth, whereas the meiofauna densities staved more or less at the same level. The ratio in biomass between meio- and macrofauna showed a dip at similar to 1000 m. At this depth...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Ecology; Sediment; Sites; Spectra; Nematoda [Nematodes].
Ano: 1999 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7325
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The systematics and ecology of free-living marine nematodes OMA
Heip, C.H.R.; Vincx, M.; Smol, N.; Vranken, G..
Nematodes are the most abundant metazoans in marine (littoral, estuarine, coastal and oceanic) sediments, extending from the high-water mark into the deepest oceanic trenches (Nicholas, 1975). All marine free-living nematodes are considered to be members of the meiobenthos; small organisms, mainly metazoans, which are separated from the larger macrobenthos either on a methodological basis (i.e. as all animals passing a 1 mm or a 0.5 mm sieve) or a taxonomic basis (i.e. particular animal groups such as Nematoda, Harpacticoida, Gastrotricha, Kinorhyncha, Tardigrada, Foraminifera etc. which consist exclusively or mainly of small species living in sediments). In most circumstances, nematodes are numerically the dominant group of the meiofauna. In fact, they...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Ecology; Systematics; Taxonomy; Nematoda [Nematodes].
Ano: 1982 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3417
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Toxicity of copper, mercury and lead to a marine nematode OMA
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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Two new species of <i>Morlaixia</i> gen. n. (Nematoda, Diplopeltidae) with a subterminal ventral mouth OMA
Vincx, M.; Gourbault, N..
A new genus of the Diplopeltidae, <i>Morlaixia</i> gen, n., is described; species are characterized by an asymmetrical anterior end, which is caused by the subventral position of the mouth opening and the buccal cavity; that feature is unique for the group. Two new species, <i>M , contusa</i> sp. n. and <i>M. obscura</i> sp. n., are described from fine sands and silty sediments in the Bay of Morlaix.
Tipo: Info:eu-repo/semantics/article Palavras-chave: New genera; New species; Morlaixia; Nematoda [Nematodes].
Ano: 1988 URL: http://www.vliz.be/imisdocs/publications/308616.pdf
Registros recuperados: 17
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