TY - JOUR
T1 - Deep-sea nematodes of the Mozambique channel
T2 - Evidence of random community assembly dynamics in seep sediments
AU - Macheriotou, Lara
AU - Rigaux, Annelien
AU - Olu, Karine
AU - Zeppilli, Daniela
AU - Derycke, Sofie
AU - Vanreusel, Ann
N1 - Funding Information:
This work was completed within the “Passive Margins Exploration Laboratories” (PAMELA) Project, co-funded by TOTAL and IFREMER. The PAMELA project is a scientific project lead by IFREMER and TOTAL in collaboration with Université de Bretagne Occidentale, Université Rennes 1, Université Pierre and Marie Curie, CNRS et IFPEN. This study was supported by Fonds Wetenschappelijk Onderzoek (FWO), grant no. 3F015515; The molecular research was carried out with infrastructure funded by EMBRC Belgium (FWO project GOH3817N).
Funding Information:
The authors would like to thank the Captain, Chief Scientist, scientific staff, and crew on board L? Atalante during the Pamela-Mozambique01 campaign. Funding. This work was completed within the ?Passive Margins Exploration Laboratories? (PAMELA) Project, co-funded by TOTAL and IFREMER. The PAMELA project is a scientific project lead by IFREMER and TOTAL in collaboration with Universit? de Bretagne Occidentale, Universit? Rennes 1, Universit? Pierre and Marie Curie, CNRS et IFPEN. This study was supported by Fonds Wetenschappelijk Onderzoek (FWO), grant no. 3F015515; The molecular research was carried out with infrastructure funded by EMBRC Belgium (FWO project GOH3817N).
Publisher Copyright:
© Copyright © 2021 Macheriotou, Rigaux, Olu, Zeppilli, Derycke and Vanreusel.
PY - 2021/2/12
Y1 - 2021/2/12
N2 - Cold seeps occur globally in areas where gases escape from the seafloor, occasionally resulting in the formation of topographic depressions (pockmarks), characterised by unique physicochemical conditions such as anoxic and sulphuric sediments. Free-living marine nematodes tend to dominate the meiofaunal component in such environments, often occurring at extremely high densities and low richness; the mechanisms defining community assembly in areas of fluid seepage, however, have received little attention. Here we focus on a low-activity pockmark at 789 m in the Mozambique Channel (MC). We assessed the diversity, co-occurrence patterns and phylogenetic community structure of nematodes at this bathyal site to that of a nearby reference area as well as abyssal sediments using metabarcoding. In addition, we compared our molecularly-derived diversity estimates to replicate samples identified morphologically. Overall, nematode Amplicon Sequence Variants (ASVs) and generic richness were similar between Pockmark and Abyssal sediments, but lower compared to the Reference area. Although more than half the genera were shared, over 80% of ASVs were unique within each area and even within each replicate core. Even though both methodologies differentiated the Pockmark from the Reference and Abyssal sites, there was little overlap between the molecularly and morphologically identified taxa, highlighting the deficit of reference sequences for deep-sea nematodes in public databases. Phylogenetic community structure at higher taxonomic levels was clustered and did not differ between the three areas yet analysis within three shared and dominant genera (Acantholaimus, Desmoscolex, Halalaimus), revealed randomness with respect to phylogeny as well as co-occurrence which was exclusive to the Pockmark area. These patterns point to the influence of neutral dynamics at this locality resulting from the stochastic sampling of early colonizing taxa, the successional stage at sampling and/or the functional redundancy within the investigated genera.
AB - Cold seeps occur globally in areas where gases escape from the seafloor, occasionally resulting in the formation of topographic depressions (pockmarks), characterised by unique physicochemical conditions such as anoxic and sulphuric sediments. Free-living marine nematodes tend to dominate the meiofaunal component in such environments, often occurring at extremely high densities and low richness; the mechanisms defining community assembly in areas of fluid seepage, however, have received little attention. Here we focus on a low-activity pockmark at 789 m in the Mozambique Channel (MC). We assessed the diversity, co-occurrence patterns and phylogenetic community structure of nematodes at this bathyal site to that of a nearby reference area as well as abyssal sediments using metabarcoding. In addition, we compared our molecularly-derived diversity estimates to replicate samples identified morphologically. Overall, nematode Amplicon Sequence Variants (ASVs) and generic richness were similar between Pockmark and Abyssal sediments, but lower compared to the Reference area. Although more than half the genera were shared, over 80% of ASVs were unique within each area and even within each replicate core. Even though both methodologies differentiated the Pockmark from the Reference and Abyssal sites, there was little overlap between the molecularly and morphologically identified taxa, highlighting the deficit of reference sequences for deep-sea nematodes in public databases. Phylogenetic community structure at higher taxonomic levels was clustered and did not differ between the three areas yet analysis within three shared and dominant genera (Acantholaimus, Desmoscolex, Halalaimus), revealed randomness with respect to phylogeny as well as co-occurrence which was exclusive to the Pockmark area. These patterns point to the influence of neutral dynamics at this locality resulting from the stochastic sampling of early colonizing taxa, the successional stage at sampling and/or the functional redundancy within the investigated genera.
KW - cold seeps
KW - community structure
KW - metabarcoding
KW - Nematoda
KW - phylogenetic community structure
U2 - 10.3389/fmars.2021.549834
DO - 10.3389/fmars.2021.549834
M3 - Article
AN - SCOPUS:85101870521
VL - 8
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
M1 - 549834
ER -