02424nas a2200229   4500008004100000245007300041210006900114260006600183300001200249490000800261520164200269653001401911653001701925653001801942653001401960653002201974653002601996100002302022700002202045700002002067856010702087       2007                        eng d00aThree-dimensional spatial structure: nematodes in a sandy tidal flat0 aThreedimensional spatial structure nematodes in a sandy tidal fl  aNORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANYbINTER-RESEARCH  a177-1860 v3363 aBenthic infauna live in a three-dimensional world, and patterns of horizontal distribution may vary with depth in the sediment, as may the mechanisms that determine those patterns. This study examines how horizontal spatial structure varies with depth in a semi-exposed coarse-sand flat adjacent to St Martin's, one of the Isles of Scilly, UK. Nematode samples were collected from 3 sediment depth horizons (0 to 5, 5 to 10 and 10 to 15 cm) in a nested hierarchical design, with samples 0.1, 1 and 10 m apart. Results show that spatial patterns are strongest amongst samples of intermediate depth (5 to 11) cm), and generally insignificant amongst samples collected from 10 to 15 cm. There is short-order spatial autocorrelation in surface (0 to 5 cm) samples, with samples collected 10 cm apart being significantly more alike than samples collected further apart. We postulate that this is because spatial structure of nematodes in surface sediments is determined by patchiness induced by interactions between the water column and the physical structure of the surface layers of the sediment, which are constantly reworked by wind and tides. The deeper layers, 10 to 15 cm below the surface, are constantly reworked by a dense population of heart urchins Echinocardium cordatum. It is only in the intermediate horizon that relatively stable conditions allow nematode assemblages to establish spatial structure over a range of scales. It is concluded that the interaction between sediment permeability, and therefore interfacial advection, and bioturbation in controlling infaunal diversity and spatial patterns is potentially important.10aadvection10abioturbation10aEchinocardium10anematodes10aspatial structure10avertical distribution1 aSomerfield, P., J.1 aDashfield, S., L.1 aWarwick, R., M.  uhttps://nematoda.myspecies.info/content/three-dimensional-spatial-structure-nematodes-sandy-tidal-flat03290nas a2200241   4500008004100000245014000041210006900181260008400250300001200334490000700346520232800353653002602681653002302707653001402730653003402744653003702778100001702815700001902832700002002851700002102871700001902892856013702911       2009                        eng d00aSpatial and seasonal variations in the ecological characteristics of the free-living nematode assemblages in a large microtidal estuary0 aSpatial and seasonal variations in the ecological characteristic  a24-28 OVAL RD, LONDON NW1 7DX, ENGLANDbACADEMIC PRESS LTD ELSEVIER SCIENCE LTD  a309-3220 v823 aThis study has determined the ways in which the density, number of species, species composition and trophic structure of free-living nematode assemblages in the subtidal waters of a large southern hemisphere microtidal estuary change spatially and seasonally, and has explored whether those four biotic characteristics are related to certain environmental factors. Based on data derived from samples collected seasonally at 12 sites throughout the estuary, the densities and number of species of nematodes decreased progressively with distance from estuary mouth, to reach a minimum at sites where salinities were most variable. and then increased slightly in the uppermost part of the estuary where salinities were least. Densities were also generally greatest in spring, due largely to increases in the abundance of epistrate-grazing species at this time and thus when the amount of primary food (microphytobenthos) peaked. The spatial distribution of the composition of the nematode assemblages was closely correlated with salinity and, to a lesser extent, grain-size composition and amount of particulate organic material (%POM) in the sediment. Although species composition changed sequentially along the estuary, the change was particularly pronounced between sites above and below the area where salinities started to decline markedly and become more variable and %POM increased markedly. This reflected, in particular, far greater abundances of Spirinia parasitifera at the six downstream sites and of Theristus sp. 1 at the six sites further upstream. Species composition underwent pronounced seasonal cyclical changes at all sites, presumably reflecting interspecific differences in the timing of peak reproduction and thus of recruitment. The trophic structure of the nematode assemblages changed both spatially and temporally in relation to the relative abundance of different food sources. Thus, for example, non-selective deposit feeders, such as Theristus sp. 1, dominated samples in the upper estuary, where %POM was by far the greatest, and was rare or absent at downstream sites. Conversely, epistrate grazers, such as species of the Chromadoridae, were most abundant at downstream sites in spring, when the density of the microphytobenthos reached its maximum. (C) 2009 Elsevier Ltd. All rights reserved.10aenvironmental factors10amicrotidal estuary10anematodes10anumber of species and density10aspecies and trophic compositions1 aHourston, M.1 aPotter, I., C.1 aWarwick, R., M.1 aValesini, F., J.1 aClarke, K., R.  uhttps://nematoda.myspecies.info/content/spatial-and-seasonal-variations-ecological-characteristics-free-living-nematode-assemblages-02400nas a2200205   4500008004100000245009800041210006900139260006800208300001200276490000800288520162400296653002501920653003001945653002601975653001402001653001602015100001402031700002002045856012902065       2006                        eng d00aGeographical variation in species diversity: A comparison of marine polychaetes and nematodes0 aGeographical variation in species diversity A comparison of mari  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BV  a234-2440 v3303 aThe aim of this study was to determine if marine species diversity was influenced by geographical location and whether it was higher at lower latitudes. Artificial collectors (made of nylon pan scourers) were employed as a standard substratum for the colonisation of marine invertebrates inhabiting subtidal (12 to 15 m) hard, rocky bottom substrata. These artificial substrate units (ASUs) were deployed at different latitudes including northern and southern temperate (South West England, UK and New Zealand), tropical (Trinidad and Tobago, West Indies) and polar (Signy Island, Antarctica) areas. The polychaetes, representative of the macrofauna and the nematodes, representative of the meiofauna fractions of the total invertebrate fauna collected were analysed. Neither polychaete nor nematode species diversity showed a trend based on latitude and each taxon showed a different pattern of diversity variation in relation to location. Polychaete diversity varied from area to area with highest species diversity occurring in the southern temperate (New Zealand). Nematode species diversity however was similar for the northern and southern temperate (UK and New Zealand) and the tropical area (Trinidad and Tobago). Thus, although the number of locations studied was limited, these data do not conform to a gradient in species diversity with latitude as has been previously supposed. The success of ASUs to compare species diversities in standardised habitat units augurs well for their future use in other ecological areas such as biogeographical or pollution studies. (C) 2006 Elsevier B.V. All rights reserved.10aartificial substrata10abenthic species diversity10alatitudinal gradients10anematodes10apolychaetes1 aGobin, JF1 aWarwick, R., M.  uhttps://nematoda.myspecies.info/content/geographical-variation-species-diversity-comparison-marine-polychaetes-and-nematodes00584nas a2200169   4500008004100000245007200041210006700113260002700180300001400207490000800221100001600229700002000245700001400265700001900279700001800298856009800316       1980                        eng d00aThe significance of free-living nematodes to the littoral ecosystem0 asignificance of freeliving nematodes to the littoral ecosystem  aLondonbAcademic Press  a729–7590 v17a1 aPlatt, H.M.1 aWarwick, R., M.1 aPrice, H.1 aIrvine, D.E.G.1 aFarnham, W.F.  uhttps://nematoda.myspecies.info/content/significance-free-living-nematodes-littoral-ecosystem00524nas a2200121   4500008004100000245010100041210006900142300001400211490000800225100002100233700002000254856012800274       1998                        eng d00aEffects of Physical Disturbance On Nematode Communities in Sand and Mud - a Microcosm Experiment0 aEffects of Physical Disturbance On Nematode Communities in Sand   a643–6500 v1301 aSchratzberger, M1 aWarwick, R., M.  uhttps://nematoda.myspecies.info/content/effects-physical-disturbance-nematode-communities-sand-and-mud-microcosm-experiment00431nas a2200121   4500008004100000245005600041210005600097300001400153490000700167100002000174700001900194856009600213       1998                        eng d00aTaxonomic distinctness and environmental assessment0 aTaxonomic distinctness and environmental assessment  a532–5430 v351 aWarwick, R., M.1 aClarke, K., R.  uhttps://nematoda.myspecies.info/content/taxonomic-distinctness-and-environmental-assessment00490nas a2200121   4500008004100000245008800041210006900129300001400198490000600212100002000218700001300238856011700251       1979                        eng d00aEcological and metabolic studies on free living nematodes from an estuarine mudflat0 aEcological and metabolic studies on free living nematodes from a  a251–2570 v91 aWarwick, R., M.1 aRice, R.  uhttps://nematoda.myspecies.info/content/ecological-and-metabolic-studies-free-living-nematodes-estuarine-mudflat00594nas a2200121   4500008004100000245016700041210006900208300001400277490000700291100002000298700001700318856013700335       2000                        eng d00aSibling species in the marine pollution indicator genus \emph{Pontonema} {Leidy} ({Nematoda: Oncholaimidae}) with a description of \emph{P. mediterranae} sp. nov.0 aSibling species in the marine pollution indicator genus emph Pon  a641–6620 v341 aWarwick, R., M.1 aRobinson, J.  uhttps://nematoda.myspecies.info/content/sibling-species-marine-pollution-indicator-genus-emphpontonema-leidy-nematoda-oncholaimidae-