@article {Somerfield:2007yf,
	title = {Three-dimensional spatial structure: nematodes in a sandy tidal flat},
	journal = {Marine Ecology-Progress Series},
	volume = {336},
	year = {2007},
	pages = {177-186},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {Benthic 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{\textquoteright}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.},
	keywords = {advection, bioturbation, Echinocardium, nematodes, spatial structure, vertical distribution},
	author = {Somerfield, P. J. and Dashfield, S. L. and Warwick, R. M.}
}
@article {Gallucci:2008la,
	title = {Active colonisation of disturbed sediments by deep-sea nematodes: evidence for the patch mosaic model},
	journal = {Marine Ecology-Progress Series},
	volume = {367},
	year = {2008},
	pages = {173-183},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {An on-board experiment was performed during a research cruise to investigate the ability of deep-sea nematode species to actively colonise defaunated sediments. Small cylinders of 500 pm wire mesh filled with defaunated sediment were inserted into microcosms containing sediment with indigenous meiofauna collected from 1300 m depth in the Arctic Ocean. The defaunated sediments were either enriched with the diatom Thalassiosira weissflogii, or remained unenriched. Samples from the defaunated sediment were taken after 9 and 17 d. As controls, microcosms with sediment containing the indigenous meiofauna but without an internal cylinder were also sampled at each time interval. Nematodes colonised both enriched and unenriched sediments with abundances of up to 20\% of the controls. Irrespective of the time of sampling, abundance and number of species were significantly higher in the enriched treatment, suggesting that the presence of food enhances colonisation and resilience. Nematode assemblages in the defaunated sediments were species-rich and differed from the controls. The majority of colonising species were rare or undetectable in the controls, suggesting that episodic disturbances may be necessary for their persistence in deep sea sediments. Colonisation was in part determined by species characteristics such as size and motility. At the same time, a large number of different species colonised the empty cylinders, resulting in poor similarity in community composition between replicates, particularly between samples enriched with diatoms. Our results indicate a poor predictability of community composition of recently disturbed sediments despite highly reproducible abundance and diversity patterns and lends experimental support to the existence of a spatio-temporal mosaic that emerges from highly localised colonisation patterns.},
	keywords = {Deep-sea, disturbance, Infauna migration, Microcosm experiments, nematodes, Patch dynamics, sediment},
	doi = {DOI 10.3354/meps07537},
	author = {Gallucci, Fabiane and Moens, Tom and Vanreusel, Ann and Fonseca, Gustavo}
}
@article {Widdicombe:2009qr,
	title = {Effects of CO2 induced seawater acidification on infaunal diversity and sediment nutrient fluxes},
	journal = {Marine Ecology-Progress Series},
	volume = {379},
	year = {2009},
	pages = {59-75},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {A mesocosm experiment was conducted to quantify the effects of short- (2 wk) and long-term (20 wk) exposure to acidified seawater on the structure and diversity of macrofaunal and nematode assemblages in 2 different sediment. types. The impact of acidified seawater on sediment nutrient fluxes was also determined. Using carbon dioxide (CO2) gas, seawater was acidified to pH 7.3 (mimicking ocean acidification), 6.5 or 5.6 (mimicking leakage from a sub-seabed CO2 store site). Control treatments were maintained in natural seawater [pH approximate to 8.0). Exposure to acidified seawater significantly altered community structure and reduced diversity for both macrofaunal and nematode assemblages, However, the impact on nematodes was less severe than that on macrofauna. While the communities in both sediment types were significantly affected by changes in seawater pH, impacts on sandy sediment fauna were greater than those on muddy sediment fauna. Sandy sediments also showed the greatest effects with respect to nutrient fluxes. In sand, the efflux of nitrite, nitrate and silicate decreased in response to increased acidification while the efflux of ammonium increased, In mud, acidification increased the efflux of ammonium but had no effect on the other nutrients. We conclude that both leakage from carbon storage and ocean acidification could cause significant changes in the structure and diversity of coastal sediment communities. Lowered seawater pH could also affect nutrient cycling directly by altering bacterial communities and indirectly through impacts on the abundance and activity of key bioturbators.},
	keywords = {Biodiversity, Carbon storage, Macrofauna, meiofauna, Nutrient flux, Ocean acidification},
	doi = {DOI 10.3354/meps07894},
	author = {Widdicombe, S. and Dashfield, S. L. and McNeill, C. L. and Needham, H. R. and Beesley, A. and McEvoy, A. and Oxnevad, S. and Clarke, K. R. and Berge, J. A.}
}
@article {Soetaert:2002tg,
	title = {Size and shape of ocean margin nematodes: morphological diversity and depth-related patterns},
	journal = {Marine Ecology-Progress Series},
	volume = {242},
	year = {2002},
	pages = {179-193},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {We studied the composition and variation of nematode body size as a function of nematode depth in the sediment and water depth at 18 stations, ranging from 137 to 4951 m depth, along the Galician margin (NE Atlantic). The analysis is based on more than 10 000 individuals and demonstrates that nematodes have adapted mainly in response to the vertical changing conditions in the sediment. Nematode length and width are similar in the upper 0.5 cm of sediment at all stations, but differ greatly as their depth in the sediment increases. The observed trends are consistent with an adaptation to changing oxygen concentrations in the sediments. In lower slope and abyssal plain stations, oxygen decreases gradually until depletion at about 5 cm depth, and nematode body width decreases concurrently, resulting in higher oxygen absorption efficiency per unit of volume. On the shelf and in the canyons, sediments become anoxic at short distances below the sediment-water interface, and more than 50\% of the nematodes are present in the anoxic part of the sediment. Here, mean nematode length increases as their depth in the sediment increases. This may result in increased mobility, which enables the organisms to migrate between anoxic patches of food and parts of the sediment where oxygen is available and/or the ability to bridge the gap between oxic and anoxic patches with their body. Order of magnitude calculation shows that in shelf sediments, the chemosynthetic bacterial production, which accompanies the oxidation of reduced substances, can not fulfill the feeding requirements of nematodes in the anoxic zone. The different size adaptations with sediment depth in shallow as compared to deep stations combined with deeper penetration of nematodes into the sediment at shallow water depth cause the observed pattern of miniaturization with increasing water depth. We conclude that nematode size distribution is determined by food availability. However, organic matter, as a food source, is not directly responsible,,as a limiting resource, but indirectly because its respiration generates reduced conditions in the sediment. Within the smaller size range (<500 mum length), there are 2 clearly distinct morphological types, which, to a certain extent, impart a taxonomic division. Similar findings at other localities suggest that this is a common feature of nematodes from ocean margin areas. One group consists of corpulent nematodes, which are less than 15 times as long as wide; most prominent in this group are members of the order of the Desmoscolecida. The other group contains significantly more slender nematodes and comprises a large variety of nematode taxa. We hypothesize that this duality in nematode design reflects an ecological adaptation designed to meet the conflicting requirements of either increased mobility (slender) or reduced vulnerability to predation (corpulent) at these small sizes.},
	keywords = {nematodes, ocean margin, sediment biogeochemistry, size-depth hypothesis},
	author = {Soetaert, K. and Muthumbi, A and HEIP, C}
}
@article {Bhadury:2006ci,
	title = {Development and evaluation of a DNA-barcoding approach for the rapid identification of nematodes},
	journal = {Marine Ecology-Progress Series},
	volume = {320},
	year = {2006},
	pages = {1-9},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {Free-living nematodes are abundant in all marine habitats, are highly diverse, and can be useful for monitoring anthropogenic impacts on the environment. Despite such attributes, nematodes are effectively ignored by many marine ecologists because of their time-consuming taxonomy. Nematode diagnostics has traditionally relied on detailed comparison of morphological characters which, given their abundance, is difficult and laborious, meaning that the biodiversity of the group is typically underestimated. Molecular methods such as DNA-barcoding offer potentially efficient alternative approaches to studying the biodiversity of marine nematode communities, allowing these organisms to be more effectively exploited in ecological surveys and environmental assessments. In this study, a number of nuclear and mitochondrial genomic regions were evaluated as potential diagnostic loci for marine nematode species identification. Of these, the 18S ribosomal RNA gene amplified most reliably from a range of taxa, and was therefore evaluated as a DNA barcode. In a comparison of molecular and morphological identifications, over 97 \% of specimens sequenced were correctly assigned on the basis of a short stretch of 18S rRNA sequence (approximately 345 bp), making this a potentially useful marker for the rapid molecular assignment of unknown nematode species, and evaluation of nematode species richness during ecological surveys or environmental assessments. This study showed that a single marker approach based on amplification and sequencing may prove invaluable in the rapid identification of nematodes during ecological surveys and, indeed, other taxonomically challenging invertebrate taxa.},
	keywords = {18S rRNA, DNA barcoding, ecological survey, identification, Marine nematodes},
	author = {Bhadury, Punyasloke and Austen, Melanie C. and Bilton, David T. and Lambshead, P. John D. and Rogers, Alex D. and Smerdon, Gary R.}
}
@article {Moens:1999ez,
	title = {Selective attraction of marine bacterivorous nematodes to their bacterial food},
	journal = {Marine Ecology-Progress Series},
	volume = {176},
	year = {1999},
	pages = {165-178},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {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 interspecific differences were noted in the nematodes{\textquoteright} response to Live or heat-killed bacteria, to bacteria at different tell densities or of different age, and to the filtered supernatant of B1 culture. While the responses of D. meyli to the Gram-positive bacteria Halobacillus trueperi and to the Gramnegative Escherichia coli were similar, D. dievengatensis and Monhystera sp, were preferentially attracted to H. trueperi and E. coli, respectively. This opposite preference influenced both the numbers and their relative abundances of D. dievengatensis and Monhystera sp, inside bacterial patches in experiments with a mixed 2-species nematode inoculum. Bacterial cell density strongly influenced the nematode response, with D, meyli invariably preferring the highest cell densities offered, while D. dievengatensis and Monhystera sp, had a peak response at lower cell densities. Though chemotaxis is suggested as an underlying mechanism, the nature of the nematodes{\textquoteright} response remains unproved. The present results strongly support the importance of food patchiness in determining the heterogeneous distribution of nematodes, and extend the concept in such a way as to allow for small differences in microhabitat choice between closely related species. They also support the view that nematodes are specialist feeders, though they probably select spots where suitable food is plentiful rather than individual food particles. Finally, the present study offers a baseline for an understanding and further study of patterns of succession among nematode species associated with decaying Spartina anglica detritus in terms of highly specific relationships with different strains, growth stages, and densities of bacteria involved in the mineralization of Spartina anglica-derived organic matter.},
	keywords = {bacteria, chemotaxis, estuarine, microdistribution, nematodes, recruitment, species succession, taxis},
	author = {Moens, T and Verbeeck, L and de Maeyer, A and Swings, J and Vincx, M}
}
