| 1. |
- Curini Galletti, Marco, et al.
(författare)
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Contribution of soft-bodied meiofaunal taxa to Italian marine biodiversity
- 2020
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Ingår i: The European Zoological Journal. - : Taylor & Francis. - 2475-0263. ; 87:1, s. 369-384
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Tidskriftsartikel (refereegranskat)abstract
- Meiofauna includes an astonishing diversity of organisms, whose census is far from being complete. Most classic ecological studies have focused on hard-bodied Ecdysozoan taxa (notably Copepoda and Nematoda), whose cuticle allows determination at species-level after fixation, rather than soft-bodied, Spiralian taxa, which most often lose any diagnostic feature in fixed samples. Yet, metabarcoding studies have recently revealed a species-richness of soft-bodied taxa comparable, and in cases superior, to that of Copepoda and Nematoda together. However, given objective difficulties inherent to their study, which necessarily has to be performed on living individuals, and their limited utilisation for ecological and applicative research, taxonomic expertise on soft-bodied organisms has declined over the years, and diversity of these phyla in most areas of the world is presently completely unknown. Here we present an expert-based survey of current knowledge on the composition and distribution of soft-bodied meiofaunal taxa in Italy, with special references to the predominantly or exclusively meiobenthic phyla Gastrotricha, Gnathostomulida, Platyhelminthes, Rotifera, Xenacoelomorpha, and macrofaunal taxa with conspicuous meiofaunal representatives (Annelida, Mollusca and Nemertea). A total of 638 described species have been reported from Italian coasts; furthermore, the existence of a large number of undescribed species is mentioned. Knowledge of Annelida, Gastrotricha, and Rotifera appears particularly detailed, placing Italy among the best-known country worldwide. In contrast, knowledge of Platyhelminthes and Xenacoelomorpha appears patchy, and limited to few areas. Sampling effort has been uneven, with most species recorded from the Tyrrhenian Sea, while large sections of the Adriatic and Ionian seas have been poorly explored. Results highlight the role that Marine Biological Stations, notably the Zoological Station “Anton Dohrn” in Naples, have had in promoting the study of soft-bodied taxa in Italy.
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| 2. |
- Eckert, EM, et al.
(författare)
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Every fifth published metagenome is not available to science.
- 2020
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1545-7885. ; 18:4
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Tidskriftsartikel (refereegranskat)abstract
- Have you ever sought to use metagenomic DNA sequences reported in scientific publications? Were you successful? Here, we reveal that metagenomes from no fewer than 20% of the papers found in our literature search, published between 2016 and 2019, were not deposited in a repository or were simply inaccessible. The proportion of inaccessible data within the literature has been increasing year-on-year. Noncompliance with Open Data is best predicted by the scientific discipline of the journal. The number of citations, journal type (e.g., Open Access or subscription journals), and publisher are not good predictors of data accessibility. However, many publications in high-impact factor journals do display a higher likelihood of accessible metagenomic data sets. Twenty-first century science demands compliance with the ethical standard of data sharing of metagenomes and DNA sequence data more broadly. Data accessibility must become one of the routine and mandatory components of manuscript submissions-a requirement that should be applicable across the increasing number of disciplines using metagenomics. Compliance must be ensured and reinforced by funders, publishers, editors, reviewers, and, ultimately, the authors.
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| 3. |
- Eckert, Ester M., et al.
(författare)
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A combination of host ecology and habitat but not evolutionary history explains differences in the microbiomes associated with rotifers
- 2023
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 850:17, s. 3813-3821
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Tidskriftsartikel (refereegranskat)abstract
- The holobiont concept places emphasis on the strict relationship between a host and its associated microbiome, with several studies supporting a strong effect of the quality of the microbiome on the host fitness. The generalities of the holobiont have been questioned for several invertebrates, including zooplankton. Here we assess the role of host ecology, habitat, and evolutionary history to explain the differences in the microbiomes associated with rotifers, across a broad taxonomic spectrum and from different habitats. The analyses of 93 rotifer-associated microbiomes from 23 rotifer host species revealed that a combination of effects from the host ecology and its habitat seem to be stronger than host phylogenetic distances in explaining differences in microbial composition of the microbiomes. This pattern is in line with the idea of habitat filtering being a stronger explanation than co-evolution in shaping the relationship between a microbiome and its rotifer host.
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| 4. |
- Jörger, Katharina, et al.
(författare)
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MEIOZORES 2019 - EXPLORING THE MARINE MEIOFAUNA OF THE AZORES
- 2021
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Ingår i: AÇOREANA. ; , s. 17-41
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Tidskriftsartikel (refereegranskat)abstract
- In July 2019 an international team of 39 senior and junior researchers from ninecountries met at the University of the Azores in Ponta Delgada, São Miguel for a 10-daysworkshop/ summer school to explore the meiofaunal biodiversity in marine sediments of the Azores. In total, we sampled intertidal and subtidal sediments from 54 localities on 14 major sites around São Miguel and additionally explored eight freshwater and terrestrial sites for rotifers. We sorted and investigated more than 2000 living specimens in the field, yielding approximately 180 species of soft-bodied meiofauna, representing most major clades of meiofauna with a focus on nematodes, polychaete annelids, proseriate andrhabdocoel flatworms, gastrotrichs, acoelomorphs, nemerteans, molluscs and cnidarians. Most of the encountered diversity shows similarities to the North-East Atlantic continental meiofauna, but in-depth morphological and molecular analyses are still pending. About 60 of the 180 species could not be assigned a species-level identification in the field, and nearly 15% of the total diversity is expected to be new to science and is awaiting formal description. Herein, we present an overview of the results of the workshop, providing detailed information on the sampling sites, methodology and encountered diversity, and we offer a preliminary discussion on aspects of faunal elements shared with other biogeographic regions. We highlight the most common members of the marine meiofauna of the Azores, provide preliminary diversity estimates and suggest a roadmap for future research towards a better understanding of the meiofauna in this remote archipelago.
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| 5. |
- Martinez, Alejandro, et al.
(författare)
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Human access impacts biodiversity of microscopic animals in sandy beaches
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Whereas most work to understand impacts of humans on biodiversity on coastal areas has focused on large, conspicuous organisms, we highlight effects of tourist access on the diversity of microscopic marine animals (meiofauna). We used a DNA metabarcoding approach with an iterative and phylogeny-based approach for the taxonomic assignment of meiofauna and relate diversity patterns to the numbers of tourists accessing sandy beaches on an otherwise un-impacted island National Park. Tourist frequentation, independently of differences in sediment granulometry, beach length, and other potential confounding factors, affected meiofaunal diversity in the shallow “swash” zone right at the mean water mark; the impacts declined with water depth (up to 2 m). The indicated negative effect on meiofauna may have a consequence on all the biota including the higher trophic levels. Thus, we claim that it is important to consider restricting access to beaches in touristic areas, in order to preserve biodiversity.
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| 6. |
- Tang, Cuong Q., et al.
(författare)
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Effects of phylogenetic reconstruction method on the robustness of species delimitation using single-locus data
- 2014
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Ingår i: Methods in Ecology and Evolution. - 2041-210X. ; 5:10, s. 1086-1094
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Tidskriftsartikel (refereegranskat)abstract
- Coalescent-based species delimitation methods combine population genetic and phylogenetic theory to provide an objective means for delineating evolutionarily significant units of diversity. The generalised mixed Yule coalescent (GMYC) and the Poisson tree process (PTP) are methods that use ultrametric (GMYC or PTP) or non-ultrametric (PTP) gene trees as input, intended for use mostly with single-locus data such as DNA barcodes. Here, we assess how robust the GMYC and PTP are to different phylogenetic reconstruction and branch smoothing methods. We reconstruct over 400 ultrametric trees using up to 30 different combinations of phylogenetic and smoothing methods and perform over 2000 separate species delimitation analyses across 16 empirical data sets. We then assess how variable diversity estimates are, in terms of richness and identity, with respect to species delimitation, phylogenetic and smoothing methods. The PTP method generally generates diversity estimates that are more robust to different phylogenetic methods. The GMYC is more sensitive, but provides consistent estimates for BEAST trees. The lower consistency of GMYC estimates is likely a result of differences among gene trees introduced by the smoothing step. Unresolved nodes (real anomalies or methodological artefacts) affect both GMYC and PTP estimates, but have a greater effect on GMYC estimates. Branch smoothing is a difficult step and perhaps an underappreciated source of bias that may be widespread among studies of diversity and diversification. Nevertheless, careful choice of phylogenetic method does produce equivalent PTP and GMYC diversity estimates. We recommend simultaneous use of the PTP model with any model-based gene tree (e.g. RAxML) and GMYC approaches with BEAST trees for obtaining species hypotheses.
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| 7. |
- Walczyńska, Aleksandra, et al.
(författare)
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Niche differentiation in rotifer cryptic species complexes : a review of environmental effects
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Ingår i: Hydrobiologia. - 0018-8158.
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Forskningsöversikt (refereegranskat)abstract
- Adaptation to different ecological niches is considered one of the main drivers of species diversification, also in cryptic species complexes, notwithstanding their morphological stasis. We here review all the published information on ecological differentiation within cryptic species complexes within the phylum Rotifera. We found 177 instances of cryptic species identified genetically, published in 101 papers. Only a subset of the papers contained available information on ecological differences and only for two of the 54 known complexes, namely Brachionus calyciflorus s.l. and Brachionus plicatilis s.l., sufficient data were available for analyses of ecological differences. For the B. calyciflorus complex, B. fernandoi consistently occurred at a significantly lower temperature than the other species in the complex; no differences were found for other environmental variables. For the B. plicatilis complex, B. paranguensis occurred in waters with higher pH than the other species; no differences were found for other environmental variables. These results, even if preliminary and based on scattered information, reveal that adaptation to different ecological niches exists also between closely related species. Our aim is to showcase this interesting field of research spurring further detailed studies to focus on the mechanisms of ecological speciation using rotifer cryptic species as a model system.
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| 8. |
- Willems, Wim, et al.
(författare)
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Meiofauna of the Koster-area, results from a workshop at the Sven Lovén Centre for Marine Sciences (Tjärnö, Sweden)
- 2009
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Ingår i: Meiofauna Marina. - : Pfeil. - 1611-7557. ; 17, s. 1-34
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Tidskriftsartikel (refereegranskat)abstract
- During a two-week workshop held at the Sven Lovén Centre for Marine Sciences on Tjärnö, an island on the Swedish west-coast, meiofauna was studied in a large variety of habitats using a wide range of sampling tech- niques. Almost 100 samples coming from littoral beaches, rock pools and different types of sublittoral sand- and mudflats yielded a total of 430 species, a conservative estimate. The main focus was on acoels, proseriate and rhabdocoel flatworms, rotifers, nematodes, gastrotrichs, copepods and some smaller taxa, like nemertodermatids, gnathostomulids, cycliophorans, dorvilleid polychaetes, priapulids, kinorhynchs, tardigrades and some other flatworms. As this is a preliminary report, some species still have to be positively identified and/or described, as 157 species were new for the Swedish fauna and 27 are possibly new to science. Each taxon is discussed separately and accompanied by a detailed species list.
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