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

Heip, C.H.R.; Smol, N..

The reproductive potential of two harpacticoid copepods, Tachidius discipes and Paronychocamptus nanus, as measured by the intrinsic rate of natural increase, rm, has been studied. The influence of temperature on all factors used in the calculation of rm has been taken into account. Generation time, which has also been detected in a third species, Nitocra typica, is the single factor which is most affected by temperature and which has the most pronounced effect on rm. Values of the reproductive potential differ considerably according to temperature, and thus to the time of the year; during the spring bloom more than half the...

The succession of benthic micrometazoans in a brackish water habitat

Ano: 1976

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3528

During the investigation of a shallow brackish water pond in northern Belgium, attention was paid to the quantitative occurrence of several micro-metazoan groups of the benthos: hydrozoa, oligochaeta, nematoda, copepoda and ostracoda. These groups show a succession in time, each group having a different moment of maximum abundance.

Nematode assemblages of deep-sea and shelf break sites in the North Atlantic and Mediterranean Sea

Palavras-chave: Benthos Brackishwater environment Ecological succession Belgium; Knokke-Heist; Dievengat.

Ano: 1971

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3426

Soetaert, K.; Heip, C.H.R..

The nematode community structure of several shelf break and deep-sea stations in the North Atlantic and the Mediterranean is compared using data from the literature. Samples from 2 Mediterranean deep-sea canyons have a unique fauna of predatory and scavenging nematodes (e.g. Synonchiella, Halichoanolaimus, Gammanema) which comprise some 20 to 30% of the community, while some of the typical deep-sea genera (Theristus, Acantholaimus) are only marginally present. The nematode generic composition of the other sites reveals a gentle transition from the shelf break (Bay of Biscay; Mediterranean) over the slope (Mediterranean) towards the continental rise, abyssal plain and hadal depths (Bay of Biscay, Puerto Rico Trench,...

The meiofauna: macrofauna ratio across the continental slope of the Goban Spur (north-east Atlantic)

Ano: 1995

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8457

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...

Production of Tachidius discipes (Copepoda: Harpacticoida)

Palavras-chave: Ecology; Sediment; Sites; Spectra; Nematoda [Nematodes].

Ano: 1999

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7325

Herman, P.M.J.; Heip, C.H.R.; Guillemijn, B..

The secondary production of the harpacticoid copepod Tachidius discipes Giesbrecht 1881 was estimated during spring 1979. The population was sampled every 3 d. Three generation peaks were observed. These were clearly distinct in the first copepodite stages, but gradually showed more overlap in older stages. Production of copepodites and adults was estimated in 2 ways: (1) Peaks were separated and the forward shifting of peaks in consecutive stages was used to estimate stage durations; (2) the size frequency method was applied. Both estimates of the production of copepodites and adults are in good agreement: 1.10 g dwt m-2 and 1.02 g dwt m-2. Egg production amounts to 0.31 g dwt...

Aspects of the life-cycle of Monhystera parelegantula (Nematoda; Monhysteridae)

Palavras-chave: Secondary production Tachidius discipes Giesbrecht; 1881.

Ano: 1984

URL: http://www.vliz.be/imisdocs/publications/238548.pdf

Vranken, G.; Thielemans, L.K.; Heip, C.H.R.; Vandycke, M..

Monhystera parelegantula (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-to), where to = 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...

Long-term evolution of the meiofauna at a sandy station in lake Grevelingen, the Netherlands

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

Willems, K.A.; Sharma, Y.; Heip, C.H.R.; Sandee, A.J.J..

Data on density, diversity and species number of harpacticoids and nematodes from a 3 m deep station in Lake Grevelingen are reported over the period 1975-1980. Vertical distribution of both copepod and nematodes densities are added. Over the 6 years period 95 species of nematodes and 26 species of harpacticoids have been identified. Neither diversity nor species number of harpacticoids changed significantly over the period. Nematode diversity and species number showed considerable changes, and especially the species composition evolved drastically over the years. The changes in feeding types among nematodes are discussed. Densities of both copepods and nematodes changed substantially over the 6 years period. Concurrent with a significant rise of the redox...

Recruitment of meroplanktonic larvae in the Southern Bight of the North Sea

Palavras-chave: Meiobenthos Population density Population dynamics Species diversity Vertical distribution Copepoda [copepods] Harpacticoida Nematoda [Nematodes] ANE; Netherlands; Grevelingen L..

Ano: 1984

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3278

Belgrano, A.; Vincx, M.; Dewarumez, J.-M.; Richard, A.; Craeymeersch, J.A.; Heip, C.H.R..

The density distribution of meroplanktonic larvae is compared with the density distribution of adults in the benthos, at five coastal stations in the Southern Bight of the North Sea (Abra alba community). Plankton communities were sampled during one tidal cycle, along a buoy traject or at a fixed point; southern and northern locations, 250 m from each central sampling point, have been investigated too. Benthos samples were taken only at the central points of this traject. Meroplankton consisted of polychaete larvae (9 families) and bivalve and echinoderm larvae. The highest density values of these larvae (6,400 ind.10.25 m2) are found on the southern sites of each traject (closest to the coastline). The highest...

A further note on wing-spreading of black storks

Palavras-chave: Meiobenthos Meroplankton Recruitment ANE; North Sea; Southern Bight.

Ano: 1990

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7114

A comparison between models describing the influence of temperature on the development rate of copepods

Ano: 1976

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6979

Four mathematical expressions relating development time to temperature are compared. All four yield good predictions of the development rate of the copepod Tachidius discipes. The use of the equation of Belehradek is criticized. It is concluded that the power equation D= aTb gives the best approximation in this case.

Hibernation in the copepod Halicyclops magniceps (Lilljeborg, 1853)

Palavras-chave: Temperature effects; Copepoda [copepods].

Ano: 1974

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3496

Halicyclops magniceps (Lilljeborg, 1853) is an inhabitant of brackish waters along the European Atlantic coasts from Germany south, and of Algeria (Dussart, 1969). During five years of investigation of a shallow brackish water pool in northern Belgium, we found the species to be the only quantitatively important cyclopoid copepod. It shows a clear yearly cycle, with one prominent peak in summer (Heip, 1973). It appears at the end of April or the beginning of May, and disappears again in October or November. Because a previous investigation, carried out in summer, had shown that copepods do not occur below a depth of 3-4 cm in the sediment, samples were limited to the first five centimeters of the sediment and included a water column of...

Het ruimtelijk patroon van meiobenthos in een meso-halien brakwatergebied

Ano: 1975

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3504

Ano: 1971

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7688

Round Table discussions

Coomans, A.; De Coninck, L.A.P.; Heip, C.H.R..

The round table discussions at the end of the meeting were summarized from tape recordings that were not always clear and voices could not always be identified. Therefore we decided to give the main ideas that were expressed and were proposed or accepted by all or a majority of the participants, without reference to any person. We hope that this summary is a true reflection of what was said with many more words.

Variability and productivity of meiobenthos in the Southern Bight of the North Sea

Ano: 1979

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6987

Heip, C.H.R.; Herman, R.; Vincx, M..

The composition and density of meiofauna in the Belgian coastal waters of the North Sea are essentially similar to those over large spatial scales. However, the impact of pollution from the Western Scheldt river is clearly reflected in a decrease in diversity on all taxonomic levels. Nematodes are the only animal group that survives in normal or even greater abundance, albeit it with lower diversity. Total meiofauna production is estimated at 1.5-2.0 g C m-2yr-1 and equals or even greatly exceeds macrofauna production in the area.

Modeling 210Pb-derived mixing activity in ocean margin sediments: diffusive versus nonlocal mixing

Palavras-chave: Biological production Meiobenthos ANE; North Sea; Southern Bight.

Ano: 1984

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3325

Soetaert, K.; Herman, P.M.J.; Middelburg, J.J.; Heip, C.H.R.; deStigter, H.S.; van Weering, T.C.E.; Epping, E.; Helder, W..

The influence of sediment mixing on activity versus depth profiles of the radionuclide 210Pb in the upper 20 cm of the sediments has been investigated along a depth transect (208 m-4500 m, 17 stations) in the OMEX study area (Goban Spur, NE Atlantic Ocean). A hierarchical family of bioturbation/nonlocal exchange models was derived. Each member of the hierarchy includes all processes of the previous model, and adds a one- or two-parameter process. The significance of the additional parameters is tested using a one-tailed F-test. It was found that (1) in five cases there is a significant improvement when direct injection of part of the flux into deeper sediment layers (nonlocal exchange) is added to the diffusive...

The size structure of nematode assemblages along a Mediterranean deep-sea transect

Palavras-chave: Chemical kinetics Continental margins Diffusion Lead 210 Modelling Sediment mixing ANE; Goban Spur.

Ano: 1996

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8450

Soetaert, K.; Heip, C.H.R..

The nematode assemblages along a deep-sea transect in the Mediterranean are composed of individuals that are as small as those found in other areas at much greater depth. This may be related to the low surface primary production since chloroplastic pigment equivalent (CPE) values in the sediments are low as well. A significant decrease of both nematode size and sedimentary CPE values with increasing water depth was found. At all water depths average nematode length increases with depth in the sediment (0-2 cm) due to the decreasing abundance of smaller nematodes.

Harpacticoid copepod community structure in two North Sea estuaries in relation to pollution

Ano: 1989

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8470

Meiobenthos as a tool in the assessment of marine environmental quality

Van Damme, D.; Heip, C.H.R.; Herman, R.; Vaeremans, M..

The harpacticoid copepod assemblages of two estuaries in the Netherlands, the Westerschelde and the Eems-Dollard, are compared. Both estuaries have similar physical characteristics but the Westerschelde is much more polluted than the Eems-Dollard. Harpacticoid copepod assemblages in both estuaries are similar in terms of species composition. However, there is a striking difference in quantitative characteristics : the highest annual averages of density, biomass and diversity in the Westerschelde are below the lowest annual averages in the Eems-Dollard estuary. Because both estuaries are extensively monitored, data concerning many possible causes of this difference could be compared. It is argued that it is the high load of heavy metals in the Westerschelde...

Tipo: Info:eu-repo/semantics/book

Palavras-chave: Estuaries Pollution Harpacticoida ANE; Netherlands; Ems-Dollard Estuary ANE; Netherlands; Westerschelde.

Ano: 1981

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7005

The assessment of the impact of pollution on the marine environment depends on the possibility of prediction either by comparison or more ideally by the analysis of time series which are long enough. Obtaining data for the construction of these time series should be one of the principal goals of monitoring. Parameters which are measured should have a low variability in time and in space or low frequency. The analysis of meiobenthic communities in the North Sea and the adjacent estuaries shows that harpacticoid copepods are especially suitable as the number and the nature of the species are stable and density, biomass, and diversity are characterized by the absence of variance in the high frequencies. Nematodes, though overwhelmingly abundant, are more...

A rapid method to evaluate nematode density

Palavras-chave: Environmental assessment; Meiobenthos; Quality control.

Ano: 1980

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3682

Drie copepoden, nieuw voor de Belgische fauna

Ano: 1974

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3493

During a research of a shallow brackish water sheet, the Dievengat, located on the territory of the region of Knokke, some copepoda were collected, amongst which three that had not previously been found in Belgium. The items originate from soil samples through means of a glass tube with a diameter of 6 cm²; it concerns a soil rich in detritus. The water is about 20 cm in depth at the location of the sample taking. Samples were taken over the period from August 1968 until May 1969. The salinity is susceptible to a relatively wide variation. Usually values between 12 promille S and 18 promille S were measured. The maximum measured was 19.03 promille S on 16/12/68 and the minimum measured 8.41 promille S on 5/5/69. According to the system of Venece, 1958, the...