Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Nematoda community

[ref. ID; 1756]

Test system

Effects of atmospheric Pb pollution on moss nematofauna

Samples

Moss samples (The southern part of the Po plain (Northern Italy), near Modena and Reggio Emilia).

Toxicants

Lead

Measurements/observations

Species diversity, number and biomass of nematodes.

[ref. ID; 3304]

Test system

6-months joint toxicity of Copper and Zinc tests

Samples

Soil collected from the top 10 cm of an arable field on acid sandy soil located 3 km NNE of Wageningen, the Netherlands.

Toxicants

Copper sulfates, Zinc sulfates, Joint toxicity.

Test design/concentrations

Plastic 7.5 l pots (20 cm diameter and 20 cm depth) were filled with treated soil and covered with 800 g fine gravel (heated to 120 degrees C to kill any nematodes present). The pots were placed at random in a greenhouse at 15 degrees C, watered to field capacity (17.7% by weight) and kept free of weeds. Cu concentrations; (0, 100, 140, 200, 280, 400, 560, and 800 mg/kg dry soil weight), Zn concentrations (0, 100, 200, 400, and 800 mg/kg dry soil weight), Cu+Zn (100/100, 200/200 mg/kg dry soil weight).

Measurements/observations

Nematode number.

Evaluations

EC50 (for single metal exposures), TU50 (for joint exposures).

[ref. ID; 6740]

Test system

Sampling site

62 sediment samples from totally eight sites of the catchments of the rivers Elbe, Order, and Rhine (Comprehensive sediment monitoring network which is operated by the German Federal Institute of Hydrology, German).

Observations

Species identification and count.

Evaluations

All multivariate statistical techniques were performed according to Clarke & Warwick (2001) using PRIMER software (Plymouth Routines in Multivariate Ecological Research; Version 5.2.9).
To evaluate the nematode community structure, multidimensional scaling ordination, based on Bray-Curtis similarities of square-root transformed relative abundance of nematode genera. Dada were transformed to increase the importance of rare genera for the multivariate analysis.
ANOSIM (analysis of similarity) was performed to test if the different sampling sites can be distinguished in terms of their nematode generic composition.
SIMPER analysis ("similarity percentages") should make clear which genera contributed most to the similarity or dissimilarity of pre-defined sample groups.
Diversity of nematode community: the number of genera and the Shannon-Wiener-Index based of generic composition.
Maturity Index: Using the equation of Bongers (1990). To test for differences of univariate indices between the various sites and river catchments, two-way nested ANOVA (general linear modles: SPSS software) and one-way ANOVA (post hoc: Tukey; SPSS software) were carried out.

[ref. ID; 6847]

Test system

Indicator of pollution

Sampling site

The Swartkops estuary (South Africa) is situated about 15 km north of the Port Elizabeth Harbour at 33 degrees 52'S and 25 degrees 38'E. The estuary is 16 km long from the mouth to the head of the estuary. Ten sampling site. Sampling was done at neap tides in the subtidal region using a hand held perspex corer, 1 m long and 6.5 cm diameter down to a depth of 10 cm.

Measurements/observations

Identification of Nematode, and density. Sediment particle size, salinity, organic carbon, chlorophyll a, concentration of heavy metals (Mn, Ti, Fe, Cr, Pb, Sn and Zn).

Evaluations

Shannon-Wiener Diversity Index and Maturity Index.

[ref. ID; 6859]

Test system

Relationships with feeding type and colonizer-persister class

Toxicants/concentrations

CuSO4 (0.0, 0.1, 0.2, 0.4, 0.8, 1.6, 3.1, 12.5, 25.0, 50.0, and 100 mM/L).

Test design

Three similar experiments were conducted using three different media, i.e., tap water, dune sand (dune), and sandy soil (sand). These soil samples were taken from an experimental field near Wageningen (The Netherlands) (sand) and from a large bulk sample, originally obtained from the Dutch dunes (dune). Temperature 20 degrees C in the dark. Exposure period 24-hr.

Measurements/observations

Count and identification for nematodes.

Evaluations

RC50 (recovery concentration 50%).

[ref. ID; 6862]

Test system

Effect on Freshwater microcosms using controlled-release method

Toxicants

4-Nonylphenol (NP). Maximum sediment concentrations: 0.29-3.37 mg/kg dry wt.

Test design

Cylindrical containers (diameter: 80 cm, height: 60 cm) made from stainless steel were filled with a 10-cm layer of natural lake sediment and 230 L water from the littoral of the oligomesotrophic Lake Ammersee (Bavaria, Germany). The microcosms were placed in an artifical outdoor pond to maintain constant temperature. An automatically operated transparent roof covered the model ecosystems during rainfall events to avoid water overflow. NP was applied in seven different concentrations by using a controlled-release device made from semipermeable low-density polyethylene tubes (tube diameter: 25 mm; membrane thickness: 54 um; retaining molecules with atomic mass>500 Da).

Measurements/Evaluations

Total nematoda abundance and species diversity (Shannon index and evenness), composition of species (multivariate method), feeding types, and different life-history strategists (maturity index).