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Sökning: WFRF:(Erséus Christer 1951) > (2015-2019)

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1.
  • Achurra, A., et al. (författare)
  • Pseudo-cryptic speciation in the subterranean medium: A new species of Stylodrilus Claparede, 1862, with a revision of the status of Bichaeta Bretscher, 1900 (Annelida, Clitellata, Lumbriculidae)
  • 2015
  • Ingår i: Zoologischer Anzeiger. - : Elsevier BV. - 0044-5231. ; 257, s. 71-86
  • Tidskriftsartikel (refereegranskat)abstract
    • The subterranean aquatic medium is known to harbor a large diversity of cryptic species. We describe a new aquatic clitellate, Stylodrilus mariae n. sp., from groundwaters in the Cantabrian region, northern Spain, using integrative taxonomy (morphological and molecular data). The new species shows inconspicuous morphological differences with Stylodrilus parvus s. lat. The tree topologies based on sequences of the barcoding gene Cytochrome Oxidase I (COI) and two nuclear markers i.e., internal transcribed spacer (ITS) region and histone 3 (H3) were concordant and revealed that S. parvus s. lat. and the new species are genetically well-differentiated. They are non-sister lineages, showing a maximum genetic (uncorrected p) distance of 20% for COI. Constrained phenotypic evolution is apparent in the clade within which S. mariae n. sp. and S. parvus are placed; this can explain the decoupling of morphological and molecular evolution in these two species although we cannot completely discard convergent evolution. Based on molecular data, the former Bichaeta sanguinea clusters within the genus Stylodrilus, and since this is concordant with the morphology, Stylodrilus sanguineus (Bretscher, 1900) n. comb, is proposed. (C) 2015 Elsevier GmbH. All rights reserved.
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4.
  • Anderson, F. E., et al. (författare)
  • Phylogenomic analyses of Crassiclitellata support major Northern and Southern Hemisphere clades and a Pangaean origin for earthworms
  • 2017
  • Ingår i: Bmc Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 17
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Earthworms (Crassiclitellata) are a diverse group of annelids of substantial ecological and economic importance. Earthworms are primarily terrestrial infaunal animals, and as such are probably rather poor natural dispersers. Therefore, the near global distribution of earthworms reflects an old and likely complex evolutionary history. Despite a long-standing interest in Crassiclitellata, relationships among and within major clades remain unresolved. Methods: In this study, we evaluate crassiclitellate phylogenetic relationships using 38 new transcriptomes in combination with publicly available transcriptome data. Our data include representatives of nearly all extant earthworm families and a representative of Moniligastridae, another terrestrial annelid group thought to be closely related to Crassiclitellata. We use a series of differentially filtered data matrices and analyses to examine the effects of data partitioning, missing data, compositional and branch-length heterogeneity, and outgroup inclusion. Results and discussion: We recover a consistent, strongly supported ingroup topology irrespective of differences in methodology. The topology supports two major earthworm clades, each of which consists of a Northern Hemisphere subclade and a Southern Hemisphere subclade. Divergence time analysis results are concordant with the hypothesis that these north-south splits are the result of the breakup of the supercontinent Pangaea. Conclusions: These results support several recently proposed revisions to the classical understanding of earthworm phylogeny, reveal two major clades that seem to reflect Pangaean distributions, and raise new questions about earthworm evolutionary relationships.
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5.
  • Bergin, Claudia, et al. (författare)
  • Acquisition of a Novel Sulfur-Oxidizing Symbiont in the Gutless Marine Worm Inanidrilus exumae
  • 2018
  • Ingår i: Applied and Environmental Microbiology. - : AMER SOC MICROBIOLOGY. - 0099-2240 .- 1098-5336. ; 84:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Gutless marine oligochaetes (Annelida, Clitellata) lack a digestive and excretory system, and live in an obligate association with multiple bacterial endosymbionts that supply them with nutrition. In this study, we discovered an unusual symbiont community in the gutless oligochaete Inanidrilus exumae that differs markedly from the microbiome of all other 22 examined host species. Comparative 16S rRNA sequence analysis and fluorescence in situ hybridization revealed that I.exumae harboured co-occurring gamma-, alpha- and deltaproteobacterial symbionts, while all other host species harbour gamma- and either alpha- or deltaproteobacterial symbionts. Surprisingly, the primary chemoautotrophic, sulfur-oxidizer, Ca. Thiosymbion, which occurs in all other gutless oligochaetes, does not appear to be present in I.exumae. Instead, I. exumae harboured a bacterial endosymbiont that resembled Ca. Thiosymbion morphologically and metabolically, but originated from a novel lineage within the Gammaproteobacteria. This endosymbiont, named Gamma 4 symbiont here, had a 16S rRNA sequence that differed by at least 7% from those of other free-living and symbiotic bacteria and by 10% from Ca. Thiosymbion. Sulfur globules in the Gamma 4 symbiont cells, as well as the presence of genes characteristic for autotrophy (cbbL) and sulfur oxidation (aprA), suggest that this symbiont is a chemoautotrophic sulfur oxidizer. Our results indicate that a novel lineage of free-living bacteria was able to establish a stable and specific association with I. exumae, and displace the Ca. Thiosymbion symbionts originally associated with these hosts.
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6.
  • Erséus, Christer, 1951, et al. (författare)
  • Klättrande daggmaskar bifångst i Malaisefällor
  • 2017
  • Ingår i: Fauna och flora. - 0014-8903. ; 112:2, s. 27-31
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • The Swedish Malaise Trap Project, with the main goal to collect insects of poorly studied groups, surprisingly also trapped 25 earthworms. They were collected at four different sites in southern Sweden and were morphologically and molecularly identified as belonging to three different species: Allolobophoridella eiseni, Dendrodrilus rubidus (rubidus and tenuis) and Eisenia andrei. Most interesting was the re-discovery of A. eiseni from Skäralid where it was previously reported by Backlund in 1946 but not often reported since. We also noticed a tendency of most worms climbing into the traps in spring and autumn, not in the summer, but more data are required to draw conclusions about this type of migration.
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7.
  • Erséus, Christer, 1951, et al. (författare)
  • Molecular data reveal a tropical freshwater origin of Naidinae (Annelida, Clitellata, Naididae)
  • 2017
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 115, s. 115-127
  • Tidskriftsartikel (refereegranskat)abstract
    • The phylogenetic relationships within Naidinae (Annelida, Clitellata, Naididae) were investigated, using six molecular markers, both mitochondrial (12S rDNA, 16S rDNA, the COI gene) and nuclear (18S rDNA, 28S rDNA, the ITS region). Thirty-seven nominal species, representing 16 of the 22 genera recognized in the subfamily, were included, and the Nais conmmmunis/variabilis species complex was represented by six different morphotypes. Ten other species of Naididae were selected as outgroups. The data were analysed by Bayesian inference and Maximum Likelihood. The phylogeny corroborates monophyly of the Naidinae, and the separate status of the genus Pristina (Pristininae) and the Opistocystinae. Relationships within Naidinae are largely well supported, but in some parts unexpected: (1) A Glade containing the largely tropical genera Dero and Branchiodrilus is sister to the rest of the subfamily, and together with a third tropical genus, Allonais, they form a basal paraphyly. All these genera show morphological adaptations to environmental hypoxia, leading to the conclusion that Naidinae originated in tropical freshwaters. (2) The genera Dero, Nais and Piguetiella are paraphyletic. (3) At least Branchiodrilus, Paranais, Chaetogaster, Nais, Stylaria appear to contain cryptic species. Morphological characters, especially those associated with chaetae, are to a great extent homoplastic within Naidinae, which certainly has contributed to the overall taxonomic confusion of this subfamily.
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8.
  • Erséus, Christer, 1951, et al. (författare)
  • New specific primers for amplification of the Internal Transcribed Spacer region in Clitellata (Annelida)
  • 2017
  • Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:23, s. 10421-10439
  • Tidskriftsartikel (refereegranskat)abstract
    • Nuclear molecular evidence, for example, the rapidly evolving Internal Transcribed Spacer region (ITS), integrated with maternally inherited (mitochondrial) COI barcodes, has provided new insights into the diversity of clitellate annelids. PCR amplification and sequencing of ITS, however, are often hampered by poor specificity of primers used. Therefore, new clitellate-specific primers for amplifying the whole ITS region (ITS: 29F/1084R) and a part of it (ITS2: 606F/1082R) were developed on the basis of a collection of previously published ITS sequences with flanking rDNA coding regions. The specificity of these and other ITS primers used for clitellates were then tested in silico by evaluating their mismatches with all assembled and annotated sequences (STD, version r127) from EMBL, and the new primers were also tested in vitro for a taxonomically broad sample of clitellate species (71 specimens representing 11 families). The in silico analyses showed that the newly designed primers have a better performance than the universal ones when amplifying clitellate ITS sequences. In vitro PCR and sequencing using the new primers were successful, in particular, for the 606F/1082R pair, which worked well for 65 of the 71 specimens. Thus, using this pair for amplifying the ITS2 will facilitate further molecular systematic investigation of various clitellates. The other pair (29F/1084R), will be a useful complement to existing ITS primers, when amplifying ITS as a whole.
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9.
  • Erséus, Christer, 1951 (författare)
  • Svenska gördelmaskar (Clitellata) och DNA streckkodning - En rapport om kunskapsläget
  • 2018
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Denna rapport sammanfattar kunskapsläget (december 2017) för ringmaskgruppen Clitellata (gördelmaskar) i Sverige. Gördelmaskar har traditionellt delats in i Hirudinea (iglar) och Oligochaeta (fåborstmaskar), men den förstnämnda gruppen är bara en deriverad del av den andra. Maskarna förekommer i alla typer av svensk natur, från djupt i havet till högt upp på kalfjället, och räknat i biomassa är de den klart dominerande smådjurstypen i många landmiljöer. Den presenterade artlistan är baserad på ett intensivt insamlingsarbete i Sverige och Norge under de senaste 10-15 åren; faunan är till stor del gemensam i de två länderna. Totalt 15.500 individer med DNA-streckkoder (COI-markören) från 1.000 olika lokaler har undersöks med genetiska och morfologiska metoder, och totalt 545 arter kan nu identifieras genetiskt i materialet efter att de mitokondriella COI-sekvenserna har jämförts med nukleära data (kärn-DNA). Avgränsningen av några få arter är dock fortfarande preliminär. Många av de vanligaste (namngivna) gördelmaskarna är artkomplex snarare än arter: komplexet består av ett antal s.k. kryptiska arter, vilka är genetiskt urskiljbara (och har antagligen egna ekologiska egenskaper), men de är morfologiskt svåra eller omöjliga att separera från varandra. Vi har 460 genetiskt verifierade arter från Sverige, 409 från Norge. Uppskattningen är att faunan i Sverige ändå idag överstiger 500 arter, men också att den formella taxonomin bara är klarlagd med valida namn för ca 300 av dessa. Minst 100 av de svenska arterna är fortfarande inte vetenskapligt beskrivna. Etableringen av ett referensbibliotek av DNA-streckkoder har påbörjats, och i december 2017 fanns COI-sekvenser av 351 skandinaviska gördelmaskarter i GenBank eller Barcoding of Life Database (BOLD). 16S-streckkoder fanns i motsvarande databaser för 171 arter. Antalet för båda markörerna ökar i takt med att taxonomin utreds för alltfler artgrupper. Rapporten diskuterar gördelmaskarnas potential och lämplighet som målorganismer i framtida miljöövervakning i vatten och på land, där streckkodbaserad artidentifiering ingår som metod. Den ger exempel på hur arternas ekologiska preferenser och funktion kan användas som biologiska indikatörer på status och förändringar i miljön. Den argumenterar också för utveckling av nya minibarkoder, som skulle möjliggöra identifiering av arter även i delvis nedbrutet DNA, t.ex. i extracellulärt miljö-DNA (eDNA) eller i gamla spritprover av djur. Slutligen sammanfattas kunskapsluckor i ett kapitel som mynnar ut i sju olika förslag: (1) Det taxonomiska arbetet på gördelmaskar i Sverige måste intensifieras och ges rimliga resurser. Här finns även hotad kompetens att rädda. (2) Stöd till kompletterande insamling av dåligt undersökta taxa, geografiska områden och habitat i Sverige, avseende gördelmaskar. (3) Stöd till kompletterande sekvenseringsarbete, där höjd också tas för inomartsvariation så att tillräckligt många olika haplotyper registreras för varje art. (4) SweBol, Naturvårdsverket, ArtDatabanken och forskare bör snarast inleda samtal om hur etableringen av referensbiblioteken för gördelmaskar ska gå till och hur den ska balanseras mot olika intressen och resurser. (5) Sverige bör arbeta för att BOLD-databasens automatiska arthypoteser (s.k. BINs) utreds för varje art av gördelmaskar. (6) För att kunna använda gördelmaskar som indikatorer i miljövakning föreslås framtagande av faktablad för olika arter. (7) Stöd till en särskild metodutveckling för identifikation av arter i gamla miljöprover rekommenderas.
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10.
  • Erséus, Christer, 1951, et al. (författare)
  • The popular model annelid Enchytraeus albidus is only one species in a complex of seashore White Worms (Clitellata, Enchytraeidae)
  • 2019
  • Ingår i: Organisms Diversity & Evolution. - : Springer Science and Business Media LLC. - 1439-6092 .- 1618-1077. ; 19:2, s. 105-133
  • Tidskriftsartikel (refereegranskat)abstract
    • The white worm Enchytraeus albidus Henle, 1837 (Clitellata, Enchytraeidae) is easy to keep in laboratory cultures, and has therefore been employed as a model organism in basic and applied biological research. Its natural habitat includes terrestrial composts and wrack beds on seashores. However, the name E. albidus is currently used for a complex of morphologically similar and closely related species. We here revise the components of the E. albidus species complex based on a sample of 100 Enchytraeus specimens from 56 sites, most of which are across Europe. These samples were DNA-barcoded for the mitochon- drial COI gene. A subset of them was sequenced for the nuclear ITS2 and H3 markers. Six species were delimited with strong support by the COI and ITS2 gene trees, as well as by a multi-locus species delimitation analysis. These species are identified morphologically and described as E. albidus s. str. (with designation of a neotype); Enchytraeus moebii (Michaelsen, 1885); Enchytraeus albellus Klinth, Erséus and Rota, sp. nov., E. cf. krumbachi (Čejka, 1913), E. sp. 1 (unnamed), and Enchytraeus polatdemiri Arslan and Timm, 2018. The last-mentioned species is a soda lake specialist, whereas E. albidus s. str. is both terrestrial and marine littoral; all other species occur only in seashores. The phylogeny of this group was estimated using the multi-species coalescent model. Monophyly of the E. albidus complex was recovered. Within this complex, three groups were recovered as monophyletic, but the relationship between them is unclear. One group comprises E. albidus s. str., E. albellus, and E. moebii; the second group E. cf. krumbachi and the unnamed E. sp. 1, and the third consists of only E. polatdemiri. This study serves as a framework for genetic identification of white worms used for experimental purposes.
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11.
  • Fend, S. V., et al. (författare)
  • Limnodrilus sulphurensis n. sp., from a sulfur cave in Colorado, USA, with notes on the morphologically similar L. profundicola (Clitellata, Naididae, Tubificinae)
  • 2016
  • Ingår i: Zootaxa. - 1175-5326. ; 4066:4, s. 451-468
  • Tidskriftsartikel (refereegranskat)abstract
    • A new species of the tubificine genus Limnodrilus is described and COI barcoded from Sulphur Cave and associated springs in Colorado, USA. The habitats are characterized by high sulfide concentrations. The new species, L. sulphurensis, is distinguished from all congeners by the elongate, nearly parallel teeth of chaetae in its anterior segments. It has a penis sheath resembling that of L. profundicola; consequently, museum specimens and new collections are examined here to resolve some of the taxonomic confusion surrounding that widespread, but uncommon species.
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12.
  • Fend, S. V., et al. (författare)
  • On Kincaidiana Altman, 1936 and Guestphalinus Michaelsen, 1933 (Annelida, Clitellata, Lumbriculidae), with the descriptions of three new species
  • 2017
  • Ingår i: European Journal of Taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 361, s. 1-46
  • Tidskriftsartikel (refereegranskat)abstract
    • Two formerly monotypic lumbriculid genera, Guestphalinus Michaelsen, 1933 and Kincaidiana Altman, 1936, are reviewed using morphological and molecular data, following the discovery of new northwestern, Nearctic species. Several populations of Kincaidiana hexatheca Altman, 1936 were examined, and both morphology and DNA data suggest a single, variable species in Pacific drainages extending from northern California through Washington, USA. Specimens of Kincaidiana from the Smith River drainage with a single, median atrium and differing genetically from K. hexatheca are assigned to K. smithi sp. nov. The chaetal morphology of North American Guestphalinus populations is variable, and two basic morphotypes are assigned to G. elephantinus sp. nov. and G. exilis sp. nov. This decision is supported by molecular data. The tree topology, based on the mitochondrial 16S rRNA and Cytochrome Oxidase I (COI), and the nuclear 28S rRNA gene sequences, confirmed the close phylogenetic relationships among the Nearctic Guestphalinus, Kincaidiana and Uktena Fend, Rodriguez & Lenat, 2015. Probable synapomorphies associating these genera include a filiform, ringed proboscis, a forward shift of reproductive organs relative to the usual position in the family, and spermathecae in the atrial segment.
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13.
  • Horn, K. M., et al. (författare)
  • Na + /K + -ATPase gene duplications in clitellate annelids are associated with freshwater colonization
  • 2019
  • Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 32:6, s. 580-591
  • Tidskriftsartikel (refereegranskat)abstract
    • Major habitat transitions, such as those from marine to freshwater habitats or from aquatic to terrestrial habitats, have occurred infrequently in animal evolution and may represent a barrier to diversification. Identifying genomic events associated with these transitions can help us better understand mechanisms that allow animals to cross these barriers and diversify in new habitats. Study of the Capitella telata and Helobdella robusta genomes allows examination of one such habitat transition (marine to freshwater) in Annelida. Initial examination of these genomes indicated that the freshwater leech H.robusta contains many more copies (12) of the sodium–potassium pump alpha-subunit (Na + /K + -ATPase) gene than does the marine polychaete C.telata (2). The sodium–potassium pump plays a key role in maintenance of cellular ionic balance and osmoregulation, and Na + /K + -ATPase duplications may have helped annelids invade and diversify in freshwater habitats. To assess whether the timing of Na + /K + -ATPase duplications coincided with the marine-to-freshwater transition in Clitellata, we used transcriptomic data from 18 annelid taxa, along with the two genomes, to infer a species phylogeny and identified Na + /K + -ATPase gene transcripts in order to infer the timing of gene duplication events using tree-based methods. The inferred timing of Na + /K + -ATPase duplication events is consistent with the timing of the initial marine-to-freshwater transition early in the history of clitellate annelids, supporting the hypothesis that gene duplications may have played a role in the annelid diversification into freshwater habitats. © 2019 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2019 European Society For Evolutionary Biology
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14.
  • Iwama, R. E., et al. (författare)
  • Broad geographic sampling and DNA barcoding do not support the presence of Helobdella stagnalis (Linnaeus, 1758) (Clitellata: Glossiphoniidae) in North America
  • 2019
  • Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4671:1, s. 1-25
  • Tidskriftsartikel (refereegranskat)abstract
    • The description of Helobdella stagnalis (Linnaeus, 1758) has emphasized the presence of a nuchal, chitinous scute located on the dorsal surface in the first third of the body as the diagnostic character for the species. Historically, identifications of species of Helobdella have relied heavily on this character and, as a result, Helobdella stagnalis has been reported from an inordinately broad geographic range, including Europe, Asia, Africa, North America, and South America. In addition to a few earlier investigations, a recent analysis showed that great genetic distances (orders of magnitude greater than previous estimations of intraspecific divergence in leeches) are present between scute-bearing specimens identified as H. stagnalis from Europe and North America, implying that H. stagnalis does not occur in North America. The present study expands the geographic boundaries of taxon sampling for both European and North American taxa, and re-examines the phylogenetic relationships and cytochrome c oxidase subunit I (COI) variation within scute-bearing species of the germs Helobdella. Our analyses include specimens putatively identified as "Helobdella stagnalis" from Sweden, Norway, Iceland, England, France, Italy, Slovenia, Turkey, Russia, and Iran, as well as numerous localities covering Canada and the USA. Our results corroborate previous studies in that European and west Asian specimens form a clade, including the neotype, which is separate from North American taxa. To alleviate future taxonomic confusion, we redescribe H. stagnalis and designate a neotype from the inferred type locality. The designation of a neotype stabilizes the taxonomy of scute bearing leeches of the genus Helobdella and enables us to definitively correct erroneous identifications reported in previous studies. We also note that at least four lineages of scute-bearing, North American species of Helobdella lack formal descriptions.
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15.
  • Klinth, Mårten, 1990, et al. (författare)
  • Investigating the Clitellata (Annelida) of Icelandic springs with alternative barcodes
  • 2019
  • Ingår i: Fauna Norvegica. - 1502-4873 .- 1891-5396. ; 39, s. 119-132
  • Tidskriftsartikel (refereegranskat)abstract
    • DNA barcoding is an invaluable tool to identify clitellates, regardless of life stage or cryptic morphology. However, as COI (the standard barcode for animals) is relatively long (658 bp), sequencing it requires DNA of high quality. When DNA is fragmented due to degradation, alternative barcodes of shorter length present an option to obtain genetic material. We attempted to sequence 187 clitellates sampled from springs in Iceland. However, the material had been stored at room temperature for two years, and DNA of the worms had degraded, and only three COI sequences were produced (i.e., <2% success rate). Using two alternative barcodes of 16S (one ca. 320 bp, the other ca. 70 bp long) we increased the number of sequenced specimens to 51. Comparisons of the 16S sequences showed that even the short 70 bp fragment contained enough genetic variation to separate all clitellate species in the material. Combined with morphological examinations we recognized a total of 23 species, where at least 8 are new records for Iceland, some belonging to genera new for Iceland: Cernosvitoviella and Pristina. All the new taxa are included in an updated species list of Icelandic Clitellata. The material revealed some stygophilic species previously known to inhabit springs, but true stygobionts, which are restricted to groundwater habitats, were not found. Our study shows that short 16S fragments can be obtained from DNA too degraded to be used in traditional COI barcoding, and contain enough genetic variation to separate closely related clitellate species.
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16.
  • Klinth, Mårten, 1990, et al. (författare)
  • Phylogeny and species delimitation of North European Lumbricillus (Clitellata, Enchytraeidae)
  • 2017
  • Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256. ; 46:1, s. 96-110
  • Tidskriftsartikel (refereegranskat)abstract
    • The enchytraeid genus Lumbricillus comprises about 80 described species of clitellate worms, which are up to a few centimetres long, and they mostly inhabit the littoral zone of nontropical marine and brackish waters world-wide. The phylogeny of this genus is poorly studied, but previous work has suggested that Lumbricillus is a non-monophyletic group. In this study, species boundaries and the phylogeny of this genus is re-assessed using more than 300 DNA-barcoded specimens (using COI mtDNA), part of which was also sequenced for two additional mitochondrial and four nuclear molecular markers. Statistical and coalescent based applications were used for the delimitation of a total of 24 species, of which 20 were identified as belonging to 17 described morphospecies; one morphospecies was found to be a complex of four delimited species, and another four delimited species could not be matched with any described species. Furthermore, gene trees, concatenation and multispecies coalescent based species trees were estimated using Bayesian inference. The estimated phylogenies confirm a non-monophyletic Lumbricillus as L. semifuscus is clearly excluded from the genus. Furthermore, the placement of a monophyletic clade consisting of L. arenarius, L. dubius, and an unidentified species varies between analyses; they are either found as the sister-group to the genus Grania or as sister-group to the remaining Lumbricillus, where the latter relationship is supported by the multispecies coalescent, which we consider as the most reliable method.
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17.
  • Klinth, Mårten, 1990, et al. (författare)
  • Taxonomy of North European Lumbricillus (Clitellata, Enchytraeidae)
  • 2017
  • Ingår i: Zookeys. - : Pensoft Publishers. - 1313-2989 .- 1313-2970. ; :703, s. 15-96
  • Tidskriftsartikel (refereegranskat)abstract
    • Lumbricillus is a genus of clitellate worms with about 80 described species that inhabit marine and limnic habitats. This study follows a recent analysis of the phylogeny of the genus based on 24 species of Lumbricillus collected mainly in Norway and Sweden. We provide the illustrated taxonomic descriptions of all these species and describe two of them as new; Lumbricillus latithecatus sp. n. and L. scandicus sp. n. Using the recent phylogeny, we informally divide Lumbricillus into five distinct morphological groups, into which we also tentatively place the Lumbricillus species not included in this study. Furthermore, we establish Claparedrilus gen. n., with the type species C. semifuscoides sp. n., and transfer Pachydrilus semifuscus Claparede, 1861 (previously referred to Lumbricillus) into said genus.
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18.
  • Kvist, S., et al. (författare)
  • Two new European species of the marine genus Tubificoides (Annelida: Clitellata: Naididae) with notes on the morphology of T. pseudogaster (Dahl, 1960)
  • 2018
  • Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4433:3, s. 561-573
  • Tidskriftsartikel (refereegranskat)abstract
    • Two new species of Tubificoides (subfamily Tubificinae), T. charlotteae n. sp. and T. mackiei n. sp., are described based on morphological analyses. Both species were flagged as potentially cryptic in a previous investigation, based on both mitochondrial and nuclear sequence data. Tubificoides charlotteae n. sp., known only from an intertidal site in southern Spain, is characterized by the lack of cuticular papillation, the possession of several needle-like hair chaetae in dorsal bundles, a cone-shaped penis sheath, and a rather large, muscular penial sac. It strongly resembles the north-west European, largely sublittoral species T. amplivasatus, but differs from this species in terms of body size, width of vas deferens, and the shape and size of both the ejaculatory duct and penial sac. Tubificoides mackiei n. sp., collected from the southeast coast of Norway and the west coast of Sweden, is characterized by the lack of cuticular papillae and hair chaetae, and the possession of a rather long penis sheath with a wide terminal opening. It shares several morphological features with the sympatric species Tubificoides pseudogaster, but is distinguished from the latter by the detailed morphology and length of the penis sheaths, the width of the atrium, and the lower maximal number of bifid chaetae in dorsal preclitellar bundles. The utility of an integrative comparative approach, combining molecules and morphology, for the identification and delineation of new taxa within Tubificoides is briefly discussed.
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19.
  • Lammers, Y., et al. (författare)
  • Clitellate worms (Annelida) in lateglacial and Holocene sedimentary DNA records from the Polar Urals and northern Norway
  • 2019
  • Ingår i: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 48:2, s. 317-329
  • Tidskriftsartikel (refereegranskat)abstract
    • While there are extensive macro- and microfossil records of a range of plants and animals from the Quaternary, earthworms and their close relatives amongst annelids are not preserved as fossils and therefore the knowledge of their past distributions is limited. This lack of fossils means that clitellate worms (Annelida) are currently underused in palaeoecological research, even though they can provide valuable information about terrestrial and aquatic environmental conditions. Their DNA might be preserved in sediments, which offers an alternative method for detection. Here we analyse lacustrine sediments from lakes in the Polar Urals, Arctic Russia, covering the period 24000-1300cal. a BP, and NE Norway, covering 10700-3300cal. a BP, using a universal mammal 16S rDNA marker. While mammals were recorded using the marker (reindeer was detected twice in the Polar Urals core at 23000 and 14000cal. a BP, and four times in the Norwegian core at 11000cal. a BP and between 3600-3300cal. a BP), worm extracellular DNA bycatch' was rather high. In this paper we present the first reported worm detection from ancient DNA. Our results demonstrate that both aquatic and terrestrial clitellates can be identified in late-Quaternary lacustrine sediments, and the ecological information retrievable from this group warrants further research with a more targeted approach.
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20.
  • Liu, Yingkui, et al. (författare)
  • Extensive cryptic diversity in the cosmopolitan sludge worm Limnodrilus hoffmeisteri (Clitellata, Naididae)
  • 2017
  • Ingår i: Organisms Diversity and Evolution. - : Springer Science and Business Media LLC. - 1439-6092 .- 1618-1077. ; 17:2, s. 477-495
  • Tidskriftsartikel (refereegranskat)abstract
    • Limnodrilus hoffmeisteri Claparède, 1862 is a common freshwater worm, often regarded as an indicator of organic pollution. The taxonomic status of this species is controversial due to great variation in morphological features. Numerous morphological forms of L. hoffmeisteri are recorded in the literature, especially from Europe and North America. Today, DNA-based species delimitation assumes that species boundaries can be more objectively and effectively estimated using genetic data rather than with morphological data alone. To investigate if L. hoffmeisteri is a single species, 295 worms identified as either L. hoffmeisteri or other similar (congeneric) morphospecies, using currently accepted morphological criteria, were collected from 82 locations in the northern hemisphere. The number of primary species hypotheses (PSHs) was first explored with cytochrome oxidase subunit I (COI), the proposed DNA barcode for animal species, and with data for all specimens. Both automatic barcoding gap discovery (ABGD) and the Bayesian general mixed Yule coalescent (bGMYC) model revealed the existence of ≥25 distinct PSHs (COI lineages) in our dataset. Then, smaller samples of individuals representing major COI lineages were used for exploration of a nuclear locus, the internal transcribed spacer (ITS) region. In the ITS gene tree (81 sequences), generated by BEAST, 16 well-supported terminal groups were found, but not all of these groups were congruent with the PSHs found in the COI tree. As results across these different analyses were inconsistent, we resorted to analyzing reciprocal monophyly between gene trees and used a minimum consensus of all evidence, suggesting that there are 13 separately evolving lineages (=13 species) within our sample. The smallest uncorrected COI p-distance between these species is 12.1%, and the largest intraspecific p-distance is 16.4%, illustrating the problem of species delimitation with a DNA-barcoding gap as the sole criterion. Ten of these species are morphologically identified as “L. hoffmeisteri,” the remaining three can be attributed to morphologically distinct congeneric species. An individual from the type locality in Switzerland was designated as a neotype of L. hoffmeisteri sensu stricto. This worm belongs to one of the ten species, and this lineage is widely distributed in Europe, Asia, and North America. The remaining nine species show a mixed distribution pattern; some appear to be endemic to a restricted area, others are Holarctic. Our results provide clues to the future revalidation of some of the nominal species today placed in synonymy with L. hoffmeisteri. A BEAST analysis, based on previously published and newly generated 16S data, suggested that this complex contains also other species than those studied by us. By integrating additional genetic data, it will be possible to identify these and additional specimens in future studies of Limnodrilus, and the neotype provides a baseline for further revisions of the taxonomy of the L. hoffmeisteri complex.
  •  
21.
  • Liu, Yingkui, et al. (författare)
  • Multi-locus phylogenetic analysis of the genus Limnodrilus (Annelida: Clitellata: Naididae)
  • 2017
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903. ; 112, s. 244-257
  • Tidskriftsartikel (refereegranskat)abstract
    • Limnodrilus species are annelid worms distributed worldwide in various freshwater sediments. The systematics of Limnodrilus has chiefly been based on morphology, but the genus has not been subject to any closer phylogenetic studies over the past two decades. To reconstruct the evolutionary history of Limnodrilus, and to assess the monophyly of this genus and its systematic position within the subfamily Tubificinae (Annelida: Clitellata: Naididae), 45 Limnodrilus specimens, representing 19 species, and 35 other naidid species (representing 24 genera) were sampled. The data consisted of sequences of three mitochondrial genes (COI, 12S and 16S rDNA) and four nuclear markers (18S and 28S rDNA, Histone 3, and ITS). The phylogeny was estimated, using Maximum Likelihood and Bayesian analyses of concatenated data of seven DNA loci, as well as a multi-locus coalescent-based approach. All analyses strongly suggest that Limnodrilus is monophyletic, but only if the morphospecies L. rubripenis is removed from it. Limnodrilus rubripenis and (at least) Baltidrilus, Lophochaeta and some species attributed to Varichaetadrilus comprise the sister group to the Glade Limnodrilus sensu stricto, and the latter is further divided into three well-supported groups. One of them contains morphospecies characterized by short cuticular penis sheaths and enlarged chaetae in anterior segments (L udekemianus, L. silvani and L. grandisetosus). The second is a small group of species with moderately long penis sheaths, i.e., L. sulphurensis and L profundicola. The third, and largest group, includes not only the multitude of cryptic species in the L hoffmeisteri complex, but also other, morphologically distinct, species nested within this complex. All studied species in this large group have long penis sheaths, which are exceptionally long in L. claparedianus, L. maumeensis, and a form morphologically intermediate between L. claparedianus and L cervix. The identification and classification of these groups provide a framework for directed sampling in further phylogenetic studies, and for revisionary work on the L. hoffmeisteri complex and other unresolved Limnodrilus species. (C) 2017 Elsevier Inc. All rights reserved.
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22.
  • Martin, P., et al. (författare)
  • Integrative species delimitation and phylogeny of the branchiate worm Branchiodrilus (Clitellata, Naididae)
  • 2018
  • Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256. ; 47:6, s. 727-742
  • Tidskriftsartikel (refereegranskat)abstract
    • The clitellate branchiate genus Branchiodrilus presently includes three nominal species with a mainly tropical distribution. A recent molecular phylogeny of the subfamily Naidinae suggested that species complexes may occur within the genus. In order to delimit species, we studied a total of 91 Branchiodrilus specimens collected in Asia, Africa and Europe; the genus is introduced in the latter area. We used an integrative approach, where genetic data were analysed for 42 specimens (single-locus and multiple-locus methods) and then compared with patterns shown by morphology. Ten Molecular Operational Taxonomic Units could be identified within Branchiodrilus, potentially representing 10 different species. Most of the delimited species are genetically well separated. In contrast, morphological scrutiny identified only three non-overlapping clusters of specimens, one of them grouping all specimens from the Palaearctic region and belonging to the same species. Other morphological groups are mostly consistent with the biogeographic distribution of species. The Oriental region harbours six species and might be the centre of origin from which Branchiodrilus species have dispersed and radiated. Two other species are present in the Afrotropical region, among them B.cleistochaeta newly obtained from the type locality and genetically characterized, but the presence of B.hortensis in Africa is queried. The taxonomic relevance of the morphological criteria traditionally used to distinguish nominal species is useless at the species level. B.hortensis and B.semperi are now considered as species inquirenda. To document the genital organs of species remains highly desirable, although hardly practicable for this species complex with a primarily asexual reproductive mode.
  •  
23.
  • Martinsson, Svante, 1985, et al. (författare)
  • A new Scandinavian Chamaedrilus species (Clitellata: Enchytraeidae), with additional notes on others
  • 2018
  • Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4521:3, s. 417-429
  • Tidskriftsartikel (refereegranskat)abstract
    • Chamaedrilus (earlier referred to as Cognettia) is a well-known genus of terrestrial and limnic enchytraeids, currently with 19 known species in the world. Some of its species are morphologically cryptic and can only be identified using genetic (DNA) information. Many of them reproduce asexually, and the prevalence of sexual mature individuals is generally low in the populations. Chamaedrilus asloae sp. nov. (Clitellata: Enchytraeidae) is described based on material from two rivers in Norway, one in Sweden, and from a wet deciduous forest in Denmark. With the material at hand, no morphological characters completely separate C. asloae from C. chalupskyi; none of the available specimens of the new species are sexually mature. However, four molecular markers (two mitochondrial, two nuclear) support that C. asloae is a distinct, separately evolved lineage, which is sister to a clade consisting of C. glandulosus and C. varisetosus. In this study, too, the fully developed sexual organs of C. chalupskyi and C. varisetosus are described and illustrated. © Copyright 2018 Magnolia Press.
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24.
  • Martinsson, Svante, 1985, et al. (författare)
  • Barcoding gap, but no support for cryptic speciation in the earthworm Aporrectodea longa (Clitellata: Lumbricidae)
  • 2017
  • Ingår i: Mitochondrial DNA. - : Informa UK Limited. - 1940-1736 .- 1940-1744. ; 28:2, s. 147-155
  • Tidskriftsartikel (refereegranskat)abstract
    • DNA-barcoding, using the mitochondrial marker COI, has been found successful for the identification of specimens in many animal groups, but may not be suited for species discovery and delimitation if used alone. In this study, we investigate whether two observed COI haplogroups in the earthworm Aporrectodea longa correspond to two cryptic species or if the variation is intraspecific. This is done by complementing COI with two nuclear markers, ITS2 and Histone 3. The variation is studied using distance methods, parsimony networks and Bayesian coalescent trees, and the statistical distinctness of the groups is tested on gene trees using the genealogical sorting index, Rosenberg’s PAB and Rodrigo et al.’s P(RD). We also applied multilocus species delimitation based on the multispecies coalescence model. The two haplogroups were found in COI, and all tests except P(RD) found them to be significantly distinct. However, in ITS2, the same groups were not recovered in any analyses or tests. H3 was invariable in A. longa, and was, therefore, included only in the multilocus analysis, which preferred a model treating A. longa as one species over a model splitting it into two. We also compared two measurements of size, body length, and no. of segments between the groups. No difference in body length was found, and although a significant difference in no. of segments was noted the haplogroup with the lower mean showed both the highest and the lowest value. When combined, these results led us to the conclusion that there is no support for the separation of A. longa into two cryptic species. This study again highlights the importance of complementing mitochondrial barcodes with more data when establishing species boundaries.
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25.
  •  
26.
  • Martinsson, Svante, 1985, et al. (författare)
  • Cryptic diversity in supposedly species-poor genera of Enchytraeidae (Annelida: Clitellata).
  • 2018
  • Ingår i: Zoological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4082 .- 1096-3642. ; 183:4, s. 749-762
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a two-step workflow, we test the species boundaries in three genera of enchytraeid worms, Globulidrilus, Hemifridericia and Stercutus (Clitellata: Enchytraeidae), which contains one to three nominal species each. For the species discovery phase, DNA barcode-based clustering analyses in ABGD (Automatic Barcode Gap Discovery) are performed, using mitochondrial cytochrome c oxidase subunit I (COI) data. The clusters from these analyses are then used as input in the species validation phase, where multispecies coalescent-based multilocus species delimitation analyses are performed in BPP (Bayesian Phylogenetics and Phylogeography) using nuclear Histone 3 (H3) and Internal Transcribed Spacer (ITS) data. For all BPP analyses, several species delimitation arrangements are included in the 95% credibility interval, and no complete sets of species are well supported. However, we conclude that our data set comprises at least seven species of Globulidrilus, all attributed to the nominal morpho-species G. riparius, three species of Hemifridericia, whereof two are cryptic lineages within H. parva and one is H. bivesiculata, and at least six species of the previously monotypic Stercutus. The species are not formally described here due to a lack of mature specimens of many of them in combination with low support for some of them in the genetic analyses. However, this is the first step towards a better understanding of the diversity within these groups.
  •  
27.
  • Martinsson, Svante, 1985, et al. (författare)
  • Cryptic speciation and limited hybridization within Lumbricus earthworms (Clitellata: Lumbricidae)
  • 2017
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 106, s. 18-27
  • Tidskriftsartikel (refereegranskat)abstract
    • Cryptic mitochondrial (mt) lineages are known to exist in the earthworm morphospecies Lumbricus rubellus and L. terrestris. The latter was recently split into two species, L. terrestris and L. herculeus, based on large genetic distances and a statistical difference in body size. There is support for the separation of some lineages in L. rubellus into species, whereas other lineages, separated by similar mt genetic distances, have been found to be part of the same species. However, no study has evaluated the status of the cryptic mt lineages in L. terrestris-L. herculeus and L. rubellus using nuclear genes. We use a combination of methods to reveal extensive cryptic speciation and limited hybridization in Lumbricus, based on one nuclear (H3) and one mitochondrial (COI) marker. Using a Bayesian multi-locus species delimitation method, as well as single gene haplotype networks and gene trees, we delimit seven well supported cryptic species within the morphospecies L. rubellus, and confirm the split within the species-pair L. terrestris-L. herculeus. Limited hybridization was found between the most common species of L. rubellus (A) in northern Europe and two other species (B and H) in this complex, as well as between L. terrestris and L. herculeus. Deep mt divergence was found within L. terrestris s.str. but no support for further splitting of this taxon was found. Both L. rubellus and L. terrestris are well studied model organisms, and considering that cryptic species and hybridization were found within them, it is important that they are properly identified in future studies.
  •  
28.
  • Martinsson, Svante, 1985, et al. (författare)
  • DNA-barcoding of invasive European earthworms (Clitellata: Lumbricidae) in south-western Australia
  • 2015
  • Ingår i: Biological Invasions. - : Springer Science and Business Media LLC. - 1387-3547 .- 1573-1464. ; 17:9, s. 2527-2532
  • Tidskriftsartikel (refereegranskat)abstract
    • Using DNA-barcoding, we studied the diversity of invasive European earthworms in the south-western corner of Australia. We found six Molecular Operational Taxonomic Units belonging to five morphospecies: Aporrectodea caliginosa, A. trapezoides, Dendrobaena cf. attemsi, Eiseniella tetraedra and Octolasion cyaneum. These were variously collected from indigenous forests and/or alienated land. Two cryptic lineages were found within A. trapezoides, and high intraspecific genetic variation was also found within E. tetraedra-variation that had previously been documented in Europe. Our study demonstrates the usefulness of DNA-barcoding for the identification of earthworms, including cryptic species. Correct identification and high taxonomic resolution is crucial for the monitoring of cryptic diversity, detecting new introductions and monitoring spread of established exotic earthworms.
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29.
  • Martinsson, Svante, 1985, et al. (författare)
  • Hybridisation and species delimitation of Scandinavian Eisenia spp. (Clitellata: Lumbricidae)
  • 2018
  • Ingår i: European Journal of Soil Biology. - : Elsevier BV. - 1164-5563. ; 88, s. 41-47
  • Tidskriftsartikel (refereegranskat)abstract
    • The earthworms Eisenia fetida and E. andrei are closely related and can hybridise under laboratory conditions, but it is not known if they hybridise under more natural conditions. The two species are genetically well separated, but within E. fetida there is also a deep split forming two well separated mitochondrial lineages. In the present study, 69 Eisenia worms from 23 outdoor (or indoor) composts or other human affected habitats in Sweden and Norway are analysed, using three molecular markers, Cytochrome C Oxidase subunit I (COI), the large 28S ribosomal subunit (28S), and Histone 3 (H3). We confirmed that E. fetida and E. andrei are separate species and, in most cases, are separated by both mitochondrial and nuclear markers, and that the two lineages of E. fetida indeed comprise a single, panmictic species despite the deep mitochondrial divergence. We did find evidence of historical hybridisation between E. andrei and E. fetida, but only in four of the 69 specimens studied.
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30.
  • Martinsson, Svante, 1985, et al. (författare)
  • On the identity of Chamaedrilus glandulosus (Michaelsen, 1888) (Clitellata, Enchytraeidae), with the description of a new species
  • 2015
  • Ingår i: Zookeys. - : Pensoft Publishers. - 1313-2989 .- 1313-2970. ; :501, s. 1-14
  • Tidskriftsartikel (refereegranskat)abstract
    • The taxonomy of Chamaedrilus glandulosus (Michaelsen, 1888) s. l., most commonly known previously as Cognettia glandulosa, is revised. A recent molecular systematic study has shown that this taxon harbours two cryptic, but genetically well separated lineages, each warranting species status. In this study these two lineages are scrutinized morphologically, on the basis of Michaelsen's type material as well as newly collected specimens from Central and Northern Europe. Chamaedrilus glandulosus s. s. is redescribed and Chamaedrilus varisetosus sp. n. is recognized as new to science. The two species are morphologically very similar, differing mainly in size, but seem to prefer different habitats, with Chamaedrilus glandulosus being a larger aquatic species, and Chamaedrilus varisetosus being smaller and mainly found in moist to wet soil.
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31.
  • Martinsson, Svante, 1985, et al. (författare)
  • Placing the forgotten: On the positions of Euenchytraeus and Chamaedrilus in an updated enchytraeid phylogeny (Clitellata : Etraeidae)
  • 2017
  • Ingår i: Invertebrate Systematics. - 1445-5226 .- 1447-2600. ; 31:1, s. 85-90
  • Tidskriftsartikel (refereegranskat)abstract
    • The phylogeny of Enchytraeidae was re-estimated to establish the relationships of the now resurrected Chamaedrilus and Euenchytraeus and to confirm their status as separate taxa. The former Cognettia (Enchytraeidae) was recently revised and split into its two senior synonyms, Chamaedrilus and Euenchytraeus, with the majority of the species transferred to Chamaedrilus. Euenchytraeus was re-established for three species sharing a unique anatomical trait, but has never before been represented in any phylogenetic study. We included representatives from 21 (of 33) valid enchytraeid genera and used three mitochondrial and four nuclear genes. The dataset (4164 base pairs) was analysed using multi-species coalescent (MSC) and maximum likelihood (ML) methods. Chamaedrilus (represented by eight species) and Euenchytraeus (represented by Eu. clarae) were found in a clade together with the monotypic Stercutus. Chamaedrilus was found to be monophyletic with maximum support in both analyses. The ML tree supported Euenchytraeus and Chamaedrilus as sister groups, whereas the MSC tree placed Euenchytraeus together with Stercutus, both with low support. A Bayes factor test weakly supported Euenchytraeus and Chamaedrilus as sister groups over Euenchytraeus + Stercutus. Possible morphological synapomorphies for these genera are discussed, and we conclude that Chamaedrilus and Euenchytraeus are closely related, but their status as separate genera is justified.
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32.
  • Martinsson, Svante, 1985, et al. (författare)
  • Revision of Cognettia (Clitellata, Enchytraeidae): re-establishment of Chamaedrilus and description of cryptic species in the sphagnetorum complex
  • 2015
  • Ingår i: Systematics and Biodiversity. - : Informa UK Limited. - 1477-2000 .- 1478-0933. ; 13:3, s. 257-277
  • Tidskriftsartikel (refereegranskat)abstract
    • The oligochaete worm, Cognettia sphagnetorum (Vejdovský, 1878), is widely used as a model organism in soil biology, and therefore it is important that its taxonomy is firmly established. A previous study based on both mitochondrial and nuclear genetic markers showed that this taxon is an assemblage of at least four species that do not form a monophyletic group. Also the validity of the genus Cognettia Nielsen and Christensen, 1959 is subject to debate, since the existence of two putative senior synonyms, Euenchytraeus Bretscher, 1906 and Chamaedrilus Friend, 1913 has been pointed out. Herein we revise the generic assignment of the species currently placed in Cognettia: two species, C. clarae Bauer, 1993 and C. piperi Christensen and Dózsa-Farkas, 1999, are transferred to Euenchytraeus, together with its type Eu. bisetosus Bretscher, 1906, whereas the remaining species, including Cognettia sphagnetorum, are being transferred to Chamaedrilus. Five species within the Chamaedrilus sphagnetorum complex are revised: the type species of Chamaedrilus, Ch. chlorophilus Friend, 1913, as well as the type species of Cognettia, Ch. sphagnetorum s. str. are redescribed, and a neotype is designated for the latter; and the cryptic species Ch. pseudosphagnetorum sp. nov. and Ch. chalupskyi sp. nov. are described as new to science and discussed against a paratype of Ch. valeriae (Dumnicka, 2010) comb. nov. DNA-barcodes are provided for all the named species in the complex except Ch. valeriae. A key to the species in the complex is given and the value of different somatic characters for separating and identifying species of Chamaedrilus is discussed. No morphological feature seems to distinguish Ch. sphagnetorum from Ch. pseudosphagnetorum. Thus, for a reliable identification of these species, molecular methods, e.g. DNA barcoding, are recommended.
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33.
  • Mejlon, Erica, et al. (författare)
  • DNA-based phylogeny of the marine genus Heterodrilus (Annelida, Clitellata, Naididae) : Phylogeny of the clitellate genus Heterodrilus
  • 2015
  • Ingår i: Journal of Zoological Systematics and Evolutionary Research. - : Hindawi Limited. - 0947-5745. ; 53:3, s. 194-199
  • Tidskriftsartikel (refereegranskat)abstract
    • Heterodrilus is a group of marine Naididae, common worldwide in subtropical and tropical areas, and unique among the oligochaetes by their triden- tate chaetae. The phylogenetic relationships within the group are assessed from the nuclear 18S rDNA gene, and the mitochondrial cytochrome c oxi- dase subunit I (COI) and 16S rDNA genes. Sequence data were obtained from 16 Heterodrilus species and 13 out-group taxa; 48 sequences are new for this study. The data were analysed by Bayesian inference. Monophyly of the genus is corroborated by the resulting tree, with Heterodrilus ersei (a taxon representing a small group of species with aberrant male genitalia) proposed to be outside all other sampled species. Although earlier regarded as a member of the subfamily Rhyacodrilinae, both molecular and morphological data seem to support that Heterodrilus is closely related to Phallodril- inae. However, the results are not conclusive as to whether the genus is the sister group of, or a group nested inside, or separate from this latter sub- family. The studied sample of species suggests at least two major clades in Heterodrilus with different geographical distributions, in one of the clades, most species are from the Indo-West Pacific Ocean, while in the other, the majority are from the Western Atlantic Ocean. Morphological characters traditionally used in Heterodrilus taxonomy are optimized on the phylogenetic tree, revealing a high degree of homoplasy.
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34.
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35.
  • Phillips, A. J., et al. (författare)
  • Phylogenomic Analysis of a Putative Missing Link Sparks Reinterpretation of Leech Evolution
  • 2019
  • Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 11:11, s. 3082-3093
  • Tidskriftsartikel (refereegranskat)abstract
    • Leeches (Hirudinida) comprise a charismatic, yet often maligned group of worms. Despite their ecological, economic, and medical importance, a general consensus on the phylogenetic relationships of major hirudinidan lineages is lacking. This absence of a consistent, robust phylogeny of early-diverging lineages has hindered our understanding of the underlying processes that enabled evolutionary diversification of this clade. Here, we used an anchored hybrid enrichment-based phylogenomic approach, capturing hundreds of loci to investigate phylogenetic relationships among major hirudinidan lineages and their closest living relatives. We recovered Branchiobdellida as sister to a clade that includes all major lineages of hirudinidans and Acanthobdella, casting doubt on the utility of Acanthobdella as a “missing link” between hirudinidans and the clitellate group formerly known as Oligochaeta. Further, our results corroborate the reciprocal monophyly of jawed and proboscis-bearing leeches. Our phylogenomic resolution of early-diverging leeches provides a useful framework for illuminating the evolution of key adaptations and host–symbiont associations that have allowed leeches to colonize a wide diversity of habitats worldwide.
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36.
  • Prantoni, Alessandro, et al. (författare)
  • Global checklist of species of Grania (Clitellata: Enchytraeidae) with remarks on their geographic distribution
  • 2017
  • Ingår i: European Journal of Taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 391, s. 1-44
  • Tidskriftsartikel (refereegranskat)abstract
    • A checklist of all currently accepted species of Grania Southern, 1913 (Annelida, Clitellata, Enchytraeidae) is presented. The genus is widespread over the world and comprises 81 species described to date. Remarks on their geographical distribution, habitat, synonymies and museum catalogue numbers are provided.
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37.
  • Prantoni, A. L., et al. (författare)
  • First reports of Grania (Clitellata: Enchytraeidae) from Africa and South America: molecular phylogeny and descriptions of nine new species
  • 2016
  • Ingår i: Zoological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4082. ; 176:3, s. 485-510
  • Tidskriftsartikel (refereegranskat)abstract
    • In this article, our knowledge of the geographic distribution of Grania species is expanded by describing seven new species, Grania bekkoucheisp.nov., Grania brasiliensissp.nov., Grania capensissp.nov., Grania chilensissp.nov., Grania crypticasp.nov., Grania hinojosaisp.nov., and Grania simonaesp.nov., from poorly investigated regions of the Southern Hemisphere, plus two new species, Grania carolinensissp.nov. and Grania unithecasp.nov., from off the east coast of the USA. An immature achaetous specimen that we call Grania cf. levis was also included. The newly generated data were combined with a previously published data set in order to update the hypothesis of phylogenetic relationships among Grania species. All new species except G.crypticasp.nov. are supported by both morphological and molecular data. In addition, we find that G.chilensissp.nov. is structured in at least four distinct populations along the Chilean coast. The species described from South Africa form a monophyletic clade where two are morphologically indistinguishable but diverging in both mitochondrial and nuclear ribosomal genes, and thus we describe them as different species, G.bekkoucheisp.nov. and G.crypticasp.nov. Among the North Carolinian species, G.unithecasp.nov. is indicated as a close relative of Grania monospermathecaErseus & Lasserre, 1976, and G.carolinensissp.nov. is indicated as a close relative of G.cf.levis. The updated phylogeny is strongly concordant with geographical species distributions, thus supporting a low level of dispersal within this genus, as has previously been hypothesized.(c) 2015 The Linnean Society of London
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38.
  • Prantoni, Alessandro L, et al. (författare)
  • Genetic diversity of marine oligochaetous clitellates in selected areas of the Southern Atlantic as revealed by DNA barcoding.
  • 2018
  • Ingår i: Invertebrate systematics. - 1445-5226 .- 1447-2600. ; 32:3, s. 524-532
  • Tidskriftsartikel (refereegranskat)abstract
    • Marine oligochaetous clitellates are poorly investigated in the South Atlantic Ocean, especially along the east coast of South America. Closely related species are often difficult to distinguish based on morphology. The lack of specialists and modern identification guides have been pointed out as the main reasons for the scarcity of studies in the South Atlantic Ocean as a whole. To increase the knowledge of this group in the South Atlantic, the genetic diversity of a sample of marine oligochaetous clitellates from Brazil, South Africa and Antarctica was assessed by the Automatic Barcode Gap Discovery (ABGD) and the generalised mixed Yule coalescent (GMYC) approaches. In total, 80 cytochrome c oxidase subunit I (COI) sequences were obtained, each with ~658 bp, estimated to represent 32 distinct putative species. ABGD established a barcoding gap between 3% and 14% divergence for uncorrected p-distances and the estimates of GMYC were largely concordant. All the clusters or putative species were genetically associated with previously known species or genera. This study thus confirms the adequacy of the COI barcoding approach combined with a genetic divergence threshold at the order of 10% for marine oligochaetous clitellates.
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39.
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40.
  • Rota, E., et al. (författare)
  • Green light to an integrative view of Microscolex phosphoreus (Duges, 1837) (Annelida: Clitellata: Acanthodrilidae)
  • 2018
  • Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4496:1, s. 175-189
  • Tidskriftsartikel (refereegranskat)abstract
    • The small synanthropic and peregrine earthworm Microscolex phosphoreus (Duges, 1837) is reported for the first time from Siberia. Morphological and DNA barcode (COI) analyses of this and widely separate samples worldwide demonstrate that, as currently identified, M. phosphoreus is a heterogeneous taxon, with divergent lineages occurring often in the same locality and hardly providing geographically structured genetic signals. The combined morphological and genetic evidence suggests that at least four of the found clades should be reclassified as separate species, both morphologically and genetically distinct from each other. However, as the specimen number was limited and only the COI gene was studied for the genetic work, we hesitate in formally describing new species. There would also be the problem of assigning the available names to specific lineages. Our findings encourage careful external and anatomical examination and using reliable characters such as the interchaetal distances and spermathecal morphology for correct identification and for deeper evaluation of cryptic diversity in this interesting bioluminescent worm.
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41.
  • Rota, E., et al. (författare)
  • Mitochondrial evidence supports a Nearctic origin for the spreading limicolous earthworm Sparganophilus tamesis Benham, 1892 (Clitellata, Sparganophilidae)
  • 2016
  • Ingår i: Contributions to Zoology. - : Brill. - 1383-4517 .- 1875-9866. ; 85:1, s. 113-119
  • Tidskriftsartikel (refereegranskat)abstract
    • We analysed samples of Sparganophilus taken at the corners of its distribution area in Europe (UK, Germany and Italy). No mitochondrial genetic divergence within and amongst them was found, neither in COI nor in 16S. Further, the COI haplotype was also identical to two sequences from Ontario, Canada in the Barcoding of Life Data System (BOLD) database. Our European COI and 16S sequences showed only minimal differentiation (only 1 or 2 substitutions) from specimens newly collected in Illinois and Washington states (USA), as well as from a COI haplotype from Tennessee (USA) in BOLD. An additional COI haplotype from Illinois (found in BOLD) is 2.1% different from the other haplotypes but clearly belongs to the same lineage of Sparganophilus. This geographically broad but genetically compact group fits the morphological diagnosis of S. tamesis Benham, 1892 as revised by Jamieson (1971) and is seen as evidence that all European populations 1) belong to the same species, 2) derive from a recent introduction, 3) are con specific with the most widespread species of Sparganophilus in North America, and that 4) S. tamesis is a senior synonym of S. eiseni Smith, 1895. The single European haplotype does not refute the possibility of its spread from a single introduced source population.
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42.
  • Rota, E., et al. (författare)
  • New data and hypotheses on the invasiveness, habitat selection, and ecological role of the limicolous earthworm Sparganophilus tamesis Benham, 1892
  • 2018
  • Ingår i: Fundamental and Applied Limnology. - : Schweizerbart. - 1863-9135. ; 192:2, s. 129-136
  • Tidskriftsartikel (refereegranskat)abstract
    • A recent molecular barcode study certified the conspecificity of mutually distant European populations of the limicolous earthworm Sparganophilus tamesis Benham, 1892 with the most widespread species of Sparganophilus in North America, and that all the analysed European worms descend from a recent introduction, probably via one or more point-source events with subsequent dispersion. We present the first records from Belgium and the Atlantic coast of southern France, and further genetic evidence confirming the species’ high dispersal abilities and historical movement within and across European drainage boundaries, as well as its capacity to establish in different types of aquatic ecosystems, including oligotrophic habitats. Experimental evidence suggests that the activity of Sparganophilus combined with that of oxygen-releasing plants, such as Lobelia dortmanna, may enhance the mobilization of refractory N pools within oligotrophic sediments, and, therefore, act as facilitator for both the macrophyte and the microbial communities in the rhizosphere. © 2018 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.
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43.
  • Rota, E., et al. (författare)
  • Two new bioluminescent Henlea from Siberia and lack of molecular support for Hepatogaster (Annelida, Clitellata, Enchytraeidae)
  • 2018
  • Ingår i: Organisms Diversity & Evolution. - : Springer Science and Business Media LLC. - 1439-6092 .- 1618-1077. ; 18:3, s. 291-312
  • Tidskriftsartikel (refereegranskat)abstract
    • Two bioluminescent enchytraeids, Henlea petushkovi sp. n. and Henlea rodionovae sp. n., are described from the Krasnoyarsk and Irkutsk regions in Eastern Siberia. These large potworms exhibit the typical light-production pattern reported repeatedly in the genus and recently elucidated by Russian researchers in its main biophysical and biochemical aspects. Morphology and DNA indicate that the two species are very closely related, but clearly divergent in the strength of the body wall (thick and opaque in H. petushkovi), structure of the prostomium (in H. rodionovae unprecedentedly wrinkled and mobile), brain shape (almost equilateral in H. petushkovi), size of coelomocytes (60–85 μm in H. petushkovi) and structure of intestinal diverticula (tulip-shaped in H. petushkovi, apple-shaped in H. rodionovae). Limited hybridization seems to occur between them, supported by a single case of conflict between COI and morphology, and a few intermediate morphotypes were noted in greenhouse populations. The new species are phylogenetically distant from all known congeners so far DNA-barcoded, even those that, like them, respond to the diagnosis of the putative subgenus Hepatogaster Čejka, 1910 (multitubular gut diverticula in VIII, indented brain, dorsal blood vessel from IX, prominent spermathecal glands, and nephridia from 5/6). In fact, our phylogenetic analyses dismiss Hepatogaster as an artificial (polyphyletic) taxon. Issues related to the definition of H. nasuta (Eisen, 1878), H. ochracea (Eisen, 1878) and H. irkutensis Burov, 1929, three species originally described from Siberia, indicate that Henlea taxonomy is still in a state of flux, as regards not only species interrelationships but also species definitions.
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44.
  • Torii, Takaaki, et al. (författare)
  • Morphological and genetic characterization of the first Species of Thalassodrilides (Annelida: Clitellata: Naididae: Limnodriloidinae) from Japan
  • 2016
  • Ingår i: Species Diversity. - : Japanese Society of Systematic Zoology. - 1342-1670 .- 2189-7301. ; 21:2, s. 117-125
  • Tidskriftsartikel (refereegranskat)abstract
    • A species of marine limnodriloidine oligochaete, Thalassodrilides cf. briani Erséus, 1992 , is recorded from gravelly sand sediments of the subtidal zone in Ehime Prefecture, Japan. The present material agrees with the original description of T. briani, which was first found at Hong Kong, with the exception that the copulatory sacs are oval; not slender. Despite the lack of genetic data for the Hong Kong population, we conclude that the Japanese specimens are conspecific with it, or at least very closely related, based on morphological considerations. This is the first record of the genus Thalassodrilides Brinkhurst and Baker, 1979 in Japan. The phylogenetic relationships between T. cf. briani and three other species of Thalassodrilides are estimated, based on partial DNA sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene and the complete nuclear ribosomal Internal Transcribed Spacer (ITS) region, using two members of the closely related genus Doliodrilus Erséus, 1984 as outgroups. The genetic analysis shows that T. cf. briani is a species delimited by both mitochondrial and nuclear data, and clearly separated from at least its closely related congeners in the Northwest Atlantic (Caribbean and adjacent areas).
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45.
  • Zimmermann, Judith, et al. (författare)
  • Closely coupled evolutionary history of ecto- and endosymbionts from two distantly-related animal phyla : Closely linked ecto- and endosymbiont evolution
  • 2016
  • Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 25:13, s. 3203-3223
  • Tidskriftsartikel (refereegranskat)abstract
    • The level of integration between associated partners can range from ectosymbioses to extracellular and intracellular endosymbioses, and this range has been assumed to reflect a continuum from less intimate to evolutionarily highly stable associations. In this study, we examined the specificity and evolutionary history of marine symbioses in a group of closely related sulphur-oxidizing bacteria, called Candidatus Thiosym- bion, that have established ecto- and endosymbioses with two distantly related animal phyla, Nematoda and Annelida. Intriguingly, in the ectosymbiotic associations of stil- bonematine nematodes, we observed a high degree of congruence between symbiont and host phylogenies, based on their ribosomal RNA (rRNA) genes. In contrast, for the endosymbioses of gutless phallodriline annelids (oligochaetes), we found only a weak congruence between symbiont and host phylogenies, based on analyses of sym- biont 16S rRNA genes and six host genetic markers. The much higher degree of con- gruence between nematodes and their ectosymbionts compared to those of annelids and their endosymbionts was confirmed by cophylogenetic analyses. These revealed 15 significant codivergence events between stilbonematine nematodes and their ectosym- bionts, but only one event between gutless phallodrilines and their endosymbionts. Phylogenetic analyses of 16S rRNA gene sequences from 50 Cand. Thiosymbion spe- cies revealed seven well-supported clades that contained both stilbonematine ectosym- bionts and phallodriline endosymbionts. This closely coupled evolutionary history of marine ecto- and endosymbionts suggests that switches between symbiotic lifestyles and between the two host phyla occurred multiple times during the evolution of the Cand. Thiosymbion clade, and highlights the remarkable flexibility of these symbiotic bacteria.
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