| 1. |
- Achurra, A., et al.
(författare)
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DNA barcoding and species delimitation: the Stylodrilus heringianus case (Annelida : Clitellata : Lumbriculidae)
- 2013
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Ingår i: Invertebrate Systematics. - 1445-5226. ; 27:1, s. 118-128
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Tidskriftsartikel (refereegranskat)abstract
- Individuals of the aquatic oligochaete species Stylodrilus heringianus Claparède, 1862 were collected across a part of this species’ distribution range in Sweden, Estonia, Great Britain and Spain to test whether they represent a single metapopulation or several separately evolving lineages. Using sequences of the barcoding gene cytochrome c oxidase subunit I (COI) and two nuclear genes (internal transcribed spacer region and histone 3), three different approaches were conducted: pairwise distance-method, Bayesian inference and network analysis. Both the COI phylogeny and network analyses were concordant in recovering six haplotype clusters, which showed a maximum genetic distance of 7.7% (K2P) among each other. Nevertheless, nuclear genes failed to confirm any lineage separation, and we conclude that the sampled specimens all belong to the same species. A phylogeographic history with allopatric divergence and secondary contact is suggested to explain this intraspecific pattern of mitochondrial divergence and nuclear non-divergence. The study shows that a mitochondrial single-locus approach can be problematic for the accurate delimitation of species, and we emphasise the need for nuclear genes as supplementary markers, when taxonomic resolution is assessed with COI barcodes.
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| 2. |
- Achurra, A., et al.
(författare)
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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
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Ingår i: Zoologischer Anzeiger. - : Elsevier BV. - 0044-5231. ; 257, s. 71-86
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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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| 3. |
- Fend, S. V., et al.
(författare)
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On Kincaidiana Altman, 1936 and Guestphalinus Michaelsen, 1933 (Annelida, Clitellata, Lumbriculidae), with the descriptions of three new species
- 2017
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Ingår i: European Journal of Taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 361, s. 1-46
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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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