| 1. |
- Iwama, R. E., et al.
(författare)
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Broad geographic sampling and DNA barcoding do not support the presence of Helobdella stagnalis (Linnaeus, 1758) (Clitellata: Glossiphoniidae) in North America
- 2019
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4671:1, s. 1-25
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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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| 2. |
- Lammers, Y., et al.
(författare)
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Clitellate worms (Annelida) in lateglacial and Holocene sedimentary DNA records from the Polar Urals and northern Norway
- 2019
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Ingår i: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 48:2, s. 317-329
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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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| 3. |
- Prantoni, Alessandro, et al.
(författare)
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Global checklist of species of Grania (Clitellata: Enchytraeidae) with remarks on their geographic distribution
- 2017
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Ingår i: European Journal of Taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 391, s. 1-44
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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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| 4. |
- Prantoni, Alessandro L, et al.
(författare)
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Genetic diversity of marine oligochaetous clitellates in selected areas of the Southern Atlantic as revealed by DNA barcoding.
- 2018
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Ingår i: Invertebrate systematics. - 1445-5226 .- 1447-2600. ; 32:3, s. 524-532
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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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