Meiofauna of the western continental shelf of India, Arabian Sea

Marine sediments in continental shelf ecosystems harbor a rich biodiversity of benthic communities. In this study, the spatial and temporal diversity and community assemblages of free-living marine nematodes were studied by sampling at six depths and over 3 years from the southwest continental shelf off Bay of Bengal, one of the least explored tropical shelf ecosystems. The dominant marine nematode species were related with abiotic variables as part of this study. The effects of sediment granulometry generally decreased with increasing depth and the highest nematode density and species diversity were recorded on coarse sand (shallower depths). Multivariate analysis of the nematode community data showed that community structure differed significantly among depths as well as among years. Statistical analyses showed significant correlations between the nematode community and abiotic variables. Sediment texture, organic matter, water pressure and depth profile were crucial factors for determining diversity, vertical profile and feeding types of the nematode community. Other environmental factors, including anthropogenic pressure, did not have an effect on nematode diversity except for the presence of some tolerant species (Metachromadora spp., Sabatieria spp. and Siplophorella sp.). This study represents a baseline of knowledge of free-living marine nematode communities that can be used in the future to compare nematode assemblages from temperate shelf ecosystems.

show abstract

“…; Sajan & Damodaran ; Sajan et al . ) and associated shallow coastal environments (Timm , ; Ansari et al . ).…”

Section: Introductionmentioning

confidence: 97%

Diversity patterns of free‐living marine nematodes in the southwest continental shelf off Bay of Bengal and their link to abiotic variables

et al. 2015

View full text Add to dashboard Cite

show abstract

“…An important observation made by our previous study (Sajan et al, 2010) was the community difference between shallow and deeper waters. Nematode community dissimilarity at various depths for each level of taxonomic resolution was tested using one-way analysis of similarity (ANOSIM , Table 1).…”

Section: Resultsmentioning

confidence: 95%

“…The Spearman rank correlations obtained for the species similarity matrices and higher taxa were generally high, although the r-values decreased from shallow to deeper waters for species relationships with genus and family. Our high resolution nematode species level data showed a depth variation in the western Indian continental shelf (Sajan et al, 2010). Secondstage MDS and ANOSIM (from PRIMER) proved significant variation in nematode community structure between various depths for all three levels of taxonomic resolution.…”

Section: Discussionmentioning

confidence: 91%

“…For this study, samples were collected from every degree square of the western Indian continental shelf (7°-22°N latitudes) with representative samples from 30, 50, 100 and 200 m depths. Nematodes were the dominant meiofaunal group, contributing 88% of the population, with 154 species belonging to 28 families, showing shifts in community structure in relation to depth (Sajan et al, 2010). With increasing depth, nematode species richness and diversity decreased, and there was significant variation in shallow water and continental margin communities.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Depth-related patterns of meiofauna on the Indian continental shelf are conserved at reduced taxonomic resolution

2010

Self Cite

View full text Add to dashboard Cite

Taxonomic sufficiency (TS) has been used in impact assessment studies of various pollution effects on marine benthic communities and found appropriate to identify the effects of pollution on marine communities. Cost, in terms of the expertise and time needed to identify organisms, increases with the level of taxonomic accuracy. Recently, TS has been adopted to study spatial patterns of macrobenthic community structure. In order to accept TS as a routine approach in wider benthic studies, it needs to be proved valid for various taxa and in geographically different areas. The present study investigates the value of TS in meiofaunal nematodes by analyzing an extensive data set based on samples collected from a wide geographical area covering a large depth gradient. For this study, samples were collected from every degree square of the western Indian continental shelf (7°-22°N latitudes). Our high resolution data showed that with increase in depth, nematode species richness and diversity decreased and communities showed significant variation between shallow and deeper waters. The present study tests whether lower taxonomic resolution nematode data can explain community shifts along a depth gradient in a similar way to species level data from the same data set. Meiofauna have often been neglected from benthic studies, and most attention has been given to macrofauna. This is mainly due to the difficulty in the taxonomic identification of meiofauna. The results of this study based on univariate and multivariate analyses support the use of family level data of nematodes to explain some aspects of depth variation in a similar way to species level data.

show abstract

“…The dominant families and genera found in this study were typical of muds or fine sands worldwide (Heip et al 1985;Soetaert & Heip 1995;De Leonardis et al 2008;Semprucci et al 2010a;Muthumbi et al 2011). Indeed, the stations above the chemocline were mainly characterised by Sabatieria, Terschellingia and Dorylaimopsis, genera well known as abundant from shallow subtidal to silty and muddy deep-sea sediments characterised by organic enrichment and even oxygen depletion (e.g., Vitiello 1974;Muthumbi et al 2004;Schratzberger et al 2006;Liu et al 2007;De Leonardis et al 2008;Gollner et al 2010;Sajan et al 2010;Vanreusel et al 2010a;Guilini et al 2012).…”

Section: Discussionmentioning

confidence: 97%

Taxonomic and functional biodiversity variations of meiobenthic and nematode assemblages across an extreme environment: a study case in a Blue Hole cave

Sandulli

Semprucci

Balsamo

2014

Italian Journal of Zoology

View full text Add to dashboard Cite

In this paper we have explored for the first time the biodiversity pattern of the meiobenthic assemblage in a Blue Hole of the Maldivian Archipelago. The cave is characterised by a marked change of the chemical water parameters below 50 m of depth, with a relevant increase in hydrogen sulfide, carbon dioxide, and sulfates (H 2 S, CO 2 and SO 4 2-). Thus, three stations were selected above and two below the chemo-thermocline in order to test the possible effects of the chemical variations on the meiobenthos. The difficulty of adaptation to these environmental conditions is clearly suggested by the presence of only a few dominant meiobenthic taxa in the bottom of the cave. However, meiobenthic organisms seemed more resistant than macrobenthos, which disappeared completely below this depth. The nematode assemblage was mainly represented by Xyalidae, Desmodoridae, Comesomatidae and Linhomoeidae. A high level of confinement of nematode genera at the different depths has been documented. In the upper part, their structure and biodiversity were comparable to those of the Maldivian subtidal habitats characterised by fine coralline sediments, while a notable dominance was detected in the bottom. The Blue Hole features also influenced the functional traits of the nematode assemblage with a documented increasing number of general opportunists and decrease of Maturity Index. The dominance of non-selective deposit feeders supports the hypothesis of a high amount of organic matter accumulated on the sea bottom of the cave.

show abstract

Meiofauna of the western continental shelf of India, Arabian Sea

Cited by 37 publications

References 34 publications

Diversity patterns of free‐living marine nematodes in the southwest continental shelf off Bay of Bengal and their link to abiotic variables

Diversity patterns of free‐living marine nematodes in the southwest continental shelf off Bay of Bengal and their link to abiotic variables

Depth-related patterns of meiofauna on the Indian continental shelf are conserved at reduced taxonomic resolution

Taxonomic and functional biodiversity variations of meiobenthic and nematode assemblages across an extreme environment: a study case in a Blue Hole cave

Contact Info

Product

Resources

About