02844nas a2200265   4500008004100000245013200041210006900173260006800242300001200310490000800322520192200330653002402252653001702276653001202293653001402305653001402319100001702333700001402350700001502364700001402379700001702393700001702410700001402427856013702441       2007                        eng d00aIndividual and combined effects of lead and zinc on a free-living marine nematode community: Results from microcosm experiments0 aIndividual and combined effects of lead and zinc on a freeliving  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BV  a217-2260 v3433 aA microcosm experiment was carried out to study the influence of lead and zinc, individually and in mixtures, on a free-living nematode community of a Tunisian lagoon. Three levels (low, medium and high) of each heavy metal were used, separately and in combinations, for sediment contamination and effects were examined after two months. Results from the multiple comparison tests showed significant differences between nematode assemblages from undisturbed controls and those from lead and/or zinc treatments. Most univariate measures, including diversity and species richness, decreased significantly in the treated microcosms. Results from multivariate analyses of the species abundance data revealed significant effects of both metals, separately or in mixtures, at all the doses tested on nematode assemblages. All treatments were significantly different from the control and from each other. Both univariate and multivariate analyses of the data showed that the differential response occurred in all treatments but the communities from microcosms contaminated with lead and zinc separately were much more strongly affected. This result is suggestive of antagonistic interactions between Pb and Zn. The responses of nematode species to the lead and zinc treatments were varied: Calomicrolaimus honestus was eliminated at all lead doses tested and seemed to be intolerant species to Pb contamination whereas Oncholaimus campylocercoides increased significantly at low and medium lead contamination, was eliminated in Pb-highly amended sediment treatments and increased at all zinc doses used. This species could be categorized as "opportunistic" at low and medium lead doses and "zinc-resistant" species. Hypodontolaimus colesi was eliminated in all replicates treated with Zn even at low concentration and appeared to be a very sensitive species to zinc contamination. (c) 2007 Elsevier B.V. All rights reserved.10acommunity structure10aheavy metals10alagoons10amicrocosm10anematodes1 aMahmoudi, E.1 aEssid, N.1 aBeyrem, H.1 aHedfi, A.1 aBoufahja, F.1 aVitiello, P.1 aAissa, P.  uhttps://nematoda.myspecies.info/content/individual-and-combined-effects-lead-and-zinc-free-living-marine-nematode-community-results-02780nas a2200277   4500008004100000245011900041210006900160260009000229300001200319490000700331520182400338653001202162653002402174653002402198653001102222653001402233653001402247653001302261100001502274700001702289700001402306700001402320700001702334700001402351856013702365       2007                        eng d00aIndividual and combined effects of cadmium and diesel on a nematode community in a laboratory microcosm experiment0 aIndividual and combined effects of cadmium and diesel on a nemat  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCE  a412-4180 v683 aA microcosm experiment was carried out to study the influence of cadmium and diesel, individually and in a mixture, on a free living nematode community of a Tunisian lagoon. Sediments were contaminated with cadmium that ranged in concentration from 0.54 to 1.40 mg Cd kg(-1) (dry weight (dw)), by diesel at 0.25 mg kg(-1) (dw), by a cadmium-diesel mixture (Cd at 1.40 mg kg(-1) + Diesel at 0.25 mg kg(-1)) and effects were examined after 90 days. Univariate analysis showed that all univariate indices did not change significantly neither at all the levels of cadmium contamination nor at 0.25 mg kg(-1) (dw) diesel concentration. But, at the cadmium-diesel mixture, significant differences were recorded between nematode assemblages from uncontaminated sediment control microcosm and those from cadmium-diesel mixture amended sediment treatments. Total nematode abundance (I), mean individual weight (bi), Shannon-Weaver index H', species richness (d), evenness (J') and number of species (S) decreased significantly in microcosms contaminated with both cadmium and diesel. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the cadmium-diesel treatments were varied: Marylynnia stekhoveni, Calomicrolaimus honestus and Oncholaimellus mediterraneus were significantly affected at the cadmium-diesel contamination but they were not eliminated. These species could be categorized as "cadmium-diesel sensitive". Enoploides sp. and Oncholaimus campylocercoides, characterized by increased abundanc s in cadmium-diesel amended sediment, seemed to be "cadmium-diesel resistant" species. All these species, "cadmium-diesel sensitive or "cadmium-diesel resistant", were not affected by either cadmium or diesel alone. (C) 2007 Elsevier Inc. All rights reserved.10acadmium10acommunity structure10acontaminant mixture10adiesel10amicrocosm10anematodes10asediment1 aBeyrem, H.1 aMahmoudi, E.1 aEssid, N.1 aHedfi, A.1 aBoufahja, F.1 aAissa, P.  uhttps://nematoda.myspecies.info/content/individual-and-combined-effects-cadmium-and-diesel-nematode-community-laboratory-microcosm-e02184nas a2200217   4500008004100000245011500041210006900156260008100225300001200306490000700318520134100325653002401666653002401690653002601714653001401740653003101754100001201785700001801797700001401815856013701829       2009                        eng d00aEnvironmental factors affecting nematode community structure in the Changjiang Estuary and its adjacent waters0 aEnvironmental factors affecting nematode community structure in   a32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USAbCAMBRIDGE UNIV PRESS  a109-1170 v893 aThis paper describes the major features of nematode assemblages collected at 18 stations in the Changiiang River estuary and its adjacent waters and identifies dominant species within communities in relation to environmental parameters. Meiofauna from the Changiiang Estuary and its adjacent waters comprised 21 major taxa of higher categories. Subsamples of nematodes were extracted and identified to the species level. In general, the nematode community structure was similar to that of muddy sub-littoral areas world-wide. The most abundant genera were Daptonema, Cobbia, Sabatieria, Dorylaimopsis and Terschellingia, accounting for 50.0%. The studied area exhibited high nematode abundance and high species biodiversity. Measurements of environmental factors were made, including grain size, salinity, temperature, sediment organic matter content, Chl-a and Phaeo-a. Different combinations of environmental variables are responsible for the meiofauna and nematode communities' structures. However, BIOENV results indicate that water depth, salinity, Chl-a, Phaeo-a and silt-clay content were more closely linked to variation in meiofauna (mainly nematode) community structure in the studied area. Among these, water depth, salinity, Chl-a and Phaeo-a were most responsible for nematode assemblage discrimination in the studied area.10aChiangjiang Estuary10acommunity structure10aenvironmental factors10anematodes10aPeople's Republic of China1 aHua, E.1 aZhang, Z., N.1 aZhang, Y.  uhttps://nematoda.myspecies.info/content/environmental-factors-affecting-nematode-community-structure-changjiang-estuary-and-its-adja