Nematode associations in the Exe estuary

Warwick, R.M.

doi:10.1017/s0025315400031908

Cited by 106 publications

(73 citation statements)

References 11 publications

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“…With a progressive increase in grain size (and, above all, a decrease in the silt-clay content), Axonolaimidae and Cyatholaimidae, and some representative species of Xyalidae, become increasingly abundant (Heip et al 1985). Indeed, the presence of these taxa has previously been documented, particularly in intertidal or sublittoral sandy substrata (Warwick 1971, Semprucci 2013. Diversity indices, unlike the trends observed in the literature (Vanaverbeke et al 2002, Semprucci et al 2010a, were not significantly affected by grain size, maintaining levels that were comparable to those recorded for other TEs.…”

Section: Effect Of Environmental Variables On Taxonomic Structure Andsupporting

confidence: 56%

“…Armenteros et al 2009, Gollner et al 2010, Guilini et al 2012. The physiological and behavioural adaptations of T. longicaudata to poorly oxygenated environments include a low respiratory rate and slow movement (Warwick andGee 1984, Guerrini et al 1998). The deposition of insoluble metal sulphides in intracellular inclusions in T. longicaudata has been suggested as a mechanism of detoxification of sulphide (Nicholas et al 1987).…”

Section: Effect Of Environmental Variables On Taxonomic Structure Andmentioning

confidence: 99%

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The nematode assemblage of a coastal lagoon (Lake Varano, southern Italy): ecology and biodiversity patterns

Semprucci¹,

Balsamo²,

Frontalini³

2014

Sci. Mar.

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Summary:This study was conducted in Lake Varano (southern Italy) in order to determine the environmental parameters that influence nematode taxonomic and functional diversity and how they influence them, and to classify for the first time the ecological quality status of a transitional environment. The general composition and level of taxonomic diversity were comparable with those reported for transitional environments worldwide. Principal component analysis revealed that the main environmental factors controlling the assemblages in terms of both composition and biological traits were grain size, organic matter, pollution load index and, only secondarily, salinity. Molgolaimus allgeni, Terschellingia longicaudata and Leptolaimus luridus showed higher values in relation to silt, organic matter and pollution load index, while Axonolaimus caudostriatus, Odontophora wieseri, Paramonhystera pellucida and Paracanthonchus longicaudatus showed higher values in relation to the redox potential and sand percentage. Salinity was detected as an influencing parameter only secondarily and particularly for Calomicrolaimus honestus, Daptonema normandicum, Thalassomonhystera parva and Sabatieria pulchra. With respect to functional traits, the trophic groups seemed to be mainly related to sediment type, which is in turn reflected by the nature of the available food. The maturity index, as well as c-p classes, did not always permit a clear interpretation of the interaction between anthropogenic and natural factors. However, the greater influence of the San Antonino and San Francesco Canals was perfectly revealed by the nematode assemblage. In accordance with the current ecological quality classes, Lake Varano can mainly be classified as having good to poor ecological quality status.Keywords: free-living nematodes; biodiversity; transitional environment; ecological quality; Lake Varano.La comunidad de nematodos de una laguna costera (Laguna de Varano, Italia meridional): patrones de la ecología y la biodiversidad Resumen: Este estudio tiene como objetivo analizar cuál y en qué medida los parámetros ambientales influyen en la diversidad taxonómica y funcional de los nematodos y clasificar por primera vez el Estado de la Calidad Ecológica (EQS) de un ambiente de transición como la laguna de Varano (Italia meridional). La composición y el nivel de divesidad taxonómica son comparables con los reportados en todo el mundo para TEs. El análisis de componentes principales reveló que los factores que controlan la composición y las características biológicas de las comunidades son el tamaño del gránulo, la materia orgá-nica (MO), el índice de aportes contaminados (PLI) y sólo secundariamente la salinidad. Molgolaimus allgeni, Terschellingia longicaudata y Leptolaimus luridus aumentan en número en relación con el limo, la MO y el PLI, mientras Axonolaimus caudostriatus, Odontophora wieseri, Paramonhystera pelúcida y Paracanthonchus longicaudatus muestran valores más altos en relación con el potencial redox y el porcentaje de arena. La salinida...

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Section: Effect Of Environmental Variables On Taxonomic Structure Andsupporting

confidence: 56%

Section: Effect Of Environmental Variables On Taxonomic Structure Andmentioning

confidence: 99%

The nematode assemblage of a coastal lagoon (Lake Varano, southern Italy): ecology and biodiversity patterns

Semprucci¹,

Balsamo²,

Frontalini³

2014

Sci. Mar.

View full text Add to dashboard Cite

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“…According to Soetaert et al (2002), depth in the sediment influences the length and width of nematodes, being consistent with an adaptation to changing oxygen concentration, with nematode body width decreasing simultaneously, resulting in higher oxygen absorption efficiency. On the other hand, long/thin nematodes were found in the downstream areas (euhaline and polyhaline areas), which could be hypothesized to be related with a more unstable environment, since this body shape is thought to be advantageous for 'hanging' in high-energy or coarse-sediment habitats (Gerlach, 1953;Wieser, 1959;Warwick, 1971;Tietjen, 1976;Thistle and Sherman, 1985).…”

Section: Biological Traits 421 Single Traitsmentioning

confidence: 99%

Taxonomic resolution and Biological Traits Analysis (BTA) approaches in estuarine free-living nematodes

Alves

Veríssimo

Costa

et al. 2014

Estuarine, Coastal and Shelf Science

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a b s t r a c tThe taxonomic and functional structure of the subtidal nematode assemblages from a temperate estuary (Mondego estuary, Portugal) was studied, focussing on different taxonomic levels (genus, family and order), on single functional groups and on multiple biological traits. Based on taxonomic levels and on four biological traits (feeding type, life strategy, tail and body shape), the analysis of the nematode assemblage distribution patterns revealed spatial differences but no clear temporal pattern. At the family and genus level, a separation of the upstream sections was observed, while a distinction of polyhaline and euhaline areas was less evident. The use of biological traits added new information regarding the relationships between diversity patterns and the environmental variables. Most nematodes encountered along the estuary were non-selective deposit feeders (1B) and omnivores/predators (2B), colonizer epersisters (score of 2 or 3), with clavate-conicocylindrical tails and slender bodies and with a distribution related essentially to salinity, oxygen and chlorophyll a. Applying a Biological Traits Analysis (BTA) showed the role of oxygen concentration in the distribution of the nematode communities. Although the BTA was no more powerful than the traditional taxonomic approach in detecting spatial differences along the Mondego estuary, it has increased our knowledge of the functional structure and characterization of nematode communities in the estuary.

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“…It would thus seem that, as for the macrofauna, salinity is the major factor involved in the zonation of nematode species in Loch Etive. This view is substantiated by a more detailed comparison of the zonation of nematode species along T. 3A in Loch Etive with the zonation in the Exe estuary described by Warwick (1971). Fortunately, several species are common to both areas.…”

Section: Nematodamentioning

confidence: 78%

Nearshore zonation of benthic fauna, especially Nematoda, in Loch Etive

Warwick¹,

Gage²

1975

J. Mar. Biol. Ass.

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The vertical distribution of the benthic fauna, including Nematoda, of soft sediments in shallow water was studied along nearshore transects at two sites in Loch Etive and compared with transects worked there previously. The mathematical techniques of hierarchical classification and reciprocal averaging ordination were applied to the species abundances along the transects in an attempt to summarize the data and describe the faunal zonation in a clear and objective way. The inverse reciprocal averaging ordination of pooled transect data described the zonation for all species at each site as a faunal gradient with a single large step at a depth where hydrographic conditions were most variable. This was the most satisfactory description of zonation since it indicated the pattern of sharp faunal change at these critical depths better than previously and allowed direct comparison between transects.The vertical distribution of the Nematoda alone could be simplified to a pattern which paralleled that of the other fauna. A single step or break demarcated a shallow brackish assemblage from a typically marine assemblage found in deeper water. Comparison with brackish fauna of the Baltic and from British estuaries illustrate the coherent nature of the brackish component. Zonation of many nematode species paralleled closely previously published descriptions of zonation in the Exe estuary, indicating the dominant effect of salinity governing distribution along the Etive transects.Classification techniques based on faunal indices of affinity between stations along the transects were less satisfactory. Different indices of faunal similarity yielded different patterns of hierarchy, although an index based on presence/absence data yielded results similar to reciprocal averaging.A group of species intermediate between the brackish and marine elements was isolated from the non-nematode component, but this was not reflected in the nematodes.

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Nematode associations in the Exe estuary

Cited by 106 publications

References 11 publications

The nematode assemblage of a coastal lagoon (Lake Varano, southern Italy): ecology and biodiversity patterns

The nematode assemblage of a coastal lagoon (Lake Varano, southern Italy): ecology and biodiversity patterns

Taxonomic resolution and Biological Traits Analysis (BTA) approaches in estuarine free-living nematodes

Nearshore zonation of benthic fauna, especially Nematoda, in Loch Etive

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