SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Moens, T.; Vierstraete, A.; Vanhove, S.; Verbeke, M.; Vincx, M..

Our current understanding of meiofaunal respiration rates, and especially of the way they are influenced by changing abiotic factors, is still far from complete. Meiofaunal respiration is traditionally measured using Cartesian divers or related manometric techniques, but these are extremely time-consuming and labour-consuming. We have evaluated the use of Strathkelvin polarographic electrode model 1302 and the O2 monitor model 781 in determining the O2 consumption of meiofaunal animals. Respiration rates obtained in this way of the terrestrial nematode Caenorhabditis elegans compared well with results obtained from Cartesian diver respirometry. Experiments with 3 estuarine nematode species...

A state of the art on meiofaunal respiration and production

Ano: 1996

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3049

The aerobic respiration of meiofauna in general and of nematodes in particular is studied by means of manometric (Cartesian or related divers) or electrode-based (polarographic electrodes) techniques. The former allow highly accurate measurements on individual or small batches of nematodes, while the latter, less sensitive technique allows rapid and highly reproducible measurements under a variety of abiotic conditions.Nematode respiration is commonly described in a power relation R = aWb, where b averages 0.75 and a represents a measure of metabolic intensity. Published estimates of total nematode community respiration are scant, but seem to agree on an average value of 61...

Do meiofauna consume primary production?: about many questions and how to answer them

Palavras-chave: Biological production; Meiobenthos; Respiration.

Ano: 1998

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7318

In view of their densities, benthic meiofauna are potentially important consumers of primary production. Feeding on diatoms and other microalgae has been documented in a variety of benthic meiotaxa, including many species of the numerically dominant nematodes and harpacticoids. Still, a detailed account of the exact diet of most species, and of the quantitative importance of primary producers in it, is lacking. For nematodes, the presumed nutritive importance of diatoms mostly derives from rather hypothetical links between buccal morphology and food. On the basis of such links, the proportion of nematodes supposedly feeding on the diatoms may amount to as much as 85%, suggesting meiofauna to importantly graze on microalgae. In estuarine and shallow coastal...

Eten en gegeten worden in het Schelde-estuarium

Ano: 1996

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3075

Moens, T.; Herman, P.M.J.; Ysebaert, T.J..

Feeding biology of a predatory and a facultatively predatory nematode (Enoploides longispiculosus and Adoncholaimus fuscus)

Ano: 2001

URL: http://www.vliz.be/imisdocs/publications/280698.pdf

Moens, T.; Verbeeck, L.; Vincx, M..

This paper reports on the feeding biology of a predatory and of a facultatively predatory nematode, Enoploides longispiculosus and Adoncholaimus fuscus, respectively. Both species represent genera which are common and abundant in the littoral of the North Sea and in adjacent estuaries. Observations on the foraging behaviour of both species are given, and for the former species, a range of prey from its natural habitat is identified. Respiration was determined using a polarographic oxygen electrode technique and compared to consumption determined as predation rates on the monhysterid nematode Diplolaimelloides meyli. The daily C-loss due to respiration accounted for 15% of the measured C-consumption...

Inferring a classification of the Adenophorea (Nematoda) from nucleotide sequences of the D3 expansion segment (26/28s rDNA)

Palavras-chave: Carbon; Communities; Communities; Communities; Ecology; Flat; Food; Marine; Meiobenthos; Water.

Ano: 1999

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7336

Litvaitis, M.K.; Bates, J.W.; Hope, W.D.; Moens, T..

Nucleotide sequences of the D3 expansion segment of the 28S rDNA gene were used to reconstruct evolutionary relationships within the Adenophorea. Neighbor-joining and parsimony analyses of representatives of most major taxa revealed a paraphyletic Adenophorea (p = 0.0005). Within Adenophorea, the Enoplia, Enoplida, and Enoplina were paraphyletic (p = 0.0024, 0.0014, and 0.0120, respectively). A major division was evident within the Enoplida, with one lineage consisting of a basal Thoracostomopsidae and Enoplidae, and a second lineage consisting of Oncholaimidae and Encheliididae. Tripyloidina clustered close to the basal enoplid branch and formed a monophyletic taxon. Although appearing as paraphyletic in the maximum-parsimony and neighbor-joining trees,...

Linking estuarine nematodes to their suspected food: a case study from the Westerschelde estuary (south-west Netherlands)

Ano: 2000

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7348

Moens, T.; Van Gansbeke, D.; Vincx, M..

The present study investigates correlations between abundances of nematodes (at the genus level) and benthic microalgae on an intertidal mudflat in the Westerschelde Estuary (south-west Netherlands), using both multi- and univariate methods. Two sample series, covering surface areas of 10 cm(2) (meioscale) and 1.25 cm(2) (microscale) per sample were analysed. Trophic type analysis indicated that an average of 31% of the nematode community were candidate grazers of microalgae. Multivariate data analysis indicated that only a limited part of the variation in the nematode data could be explained in relation to pigments. Total nematodes did not show any correlation with the pigment data. On the meioscale, the genera Tripyloides and...

Observations on the feeding ecology of estuarine nematodes

Palavras-chave: Ecology; Marine nematodes; Meiobenthos; Populations; Populations; Scale; Scale; Bacteria.

Ano: 1999

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7332

Observations on living estuarine nematodes show that previous feeding type classifications do not accurately represent the trophic structure of an intertidal mudflat in the Westerschelde Estuary (Netherlands). A new scheme with six major nematode feeding guilds is proposed: (1) microvores; (2) ciliate feeders; and (3) deposit feeders sensu stricto are all nematodes without a distinct buccal armature. In the first two groups bacteria and protozoa, respectively are the major particulate food sources, while other items are included in the diet of the third. The three other categories are recognized among the nematodes with a buccal armature: (4) epigrowth feeders; (5) facultative predators; and (6) predators. Diatoms and other microalgae are an important...

On the cultivation of free-living marine and estuarine nematodes

Palavras-chave: Biology; Biomass; Carbon; Habits; Habits; Meiobenthos; Water.

Ano: 1997

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7298

Although a large body of literature exists on the systematics and ecology of free-living marine and brackish-water nematodes, key questions on the nature and magnitude of interactions between nematodes and other organisms in the benthos remain unanswered. Relatively few authors have investigated live nematodes in food web studies or in experiments dealing with the nematodes' response to a varying environment. It is mainly for the latter purpose that attempts have been made to maintain, rear and cultivate selected species. This paper describes the methodology used for the maintenance, rearing, and eventual permanent agnotobiotic cultivation of a variety of estuarine nematodes. Spot plates, where small samples of sediment or macrophyte material are...

Preservation and incubation time-induces biais in tracer aided grazing studies on meiofauna

Palavras-chave: Cultivation Cultivation Cultivation Culture Culture Maintenance Maintenance Maintenance Marine Meiobenthos Mineralization Temperature Monhystera disjuncta Nematoda [Nematodes] ANE; Netherlands; Westerschelde.

Ano: 1998

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7316

Moens, T.; Verbeeck, L.; Vincx, M..

Selective attraction of marine bacterivorous nematodes to their bacterial food

Ano: 1999

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7338

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, Diplolaimelloides meyli, Diplolaimella dievengatensis, Monhystera sp. and Geomonhystera disjuncta, was studied in a multiple choice design. In our study area, the 4 nematode species considered are associated with Spartina anglica 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...

Temperature and salinity constraints on the life cycle of two brackish-water nematode species

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

The present study investigates the influence of salinity and temperature on the life history of two estuarine bacterivorous nematode species, Pellioditis marina and Diplolaimelloides meyli, 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 P. marina) or five (for D. meyli) 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....

Temperature, salinity and food thresholds in two brackish-water bacterivorous nematode species: assessing niches from food absorption and respiration experiments

Palavras-chave: Nematoda [Nematodes].

Ano: 2000

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7421

Respiration and food assimilation of two estuarine bacterivorous nematodes, the rhabditid Pellioditis marina and the monhysterid Diplolaimelloides meyli, 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 P. marina and D. meyli. Respiration and assimilation in both species showed only minor...

The fate of intertidal microphytobenthos carbon: an in situ 13C-labeling study

Palavras-chave: Nematoda [Nematodes].

Ano: 2000

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7422

Middelburg, J.J.; Barranguet, C.; Boschker, H.T.S.; Herman, P.M.J.; Moens, T.; Heip, C.H.R..

At two intertidal sites (one sandy and one silty, in the Scheldt estuary, The Netherlands), the fate of microphytobenthos was studied through an in situ 13C pulse- chase experiment. Label was added at the beginning of low tide, and uptake of 13C by algae was linear during the whole period of tidal exposure (about 27 mg m-2 h-1 in the top millimeter at both sites). The 13C fixed by microphytobenthos was rapidly displaced toward deeper sediment layers (down to 6 cm), in particular at the dynamic, sandy site. The residence times of microphytobenthos with respect to external losses (resuspension and respiration) were about 2.4 and 5.6 d at the...