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1.	Achurra, A., et al. (author) DNA barcoding and species delimitation: the Stylodrilus heringianus case (Annelida : Clitellata : Lumbriculidae) 2013 In: Invertebrate Systematics. - 1445-5226. ; 27:1, s. 118-128 Journal article (peer-reviewed)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.
2.	Achurra, A., et al. (author) 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 In: Zoologischer Anzeiger. - : Elsevier BV. - 0044-5231. ; 257, s. 71-86 Journal article (peer-reviewed)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.
3.	Anderson, Frank E., et al. (author) Earthworms are polychaetes, too: phylogenomic analyses of relationships within Crassiclitellata 2016 In: SICB 2016 Annual Meeting Abstracts; January 3-7, 2016, Portland Oregon USA. Integrative and Comparative Biology 56 (Suppl. 1): e6. - : Oxford University Press (OUP). - 1540-7063. Conference paper (other academic/artistic)
4.	Anderson, Frank E, et al. (author) Erratum to: Phylogenomic analyses of Crassiclitellata support major Northern and Southern hemisphere clades and a Pangaean origin for earthworms 2017 In: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 17 Other publication (other academic/artistic)abstract After publication of the original article [1], the authors received the correct museum catalogue number of Avelona ligra, Lumbricidae, which is listed in Table 1. The museum number currently reads MNHN XXXXXX in the original article, but should read MNHN HEL593. A full, updated version of the amended Table (Table 1) is included in this Erratum.
5.	Anderson, F. E., et al. (author) Phylogenomic analyses of Crassiclitellata support major Northern and Southern Hemisphere clades and a Pangaean origin for earthworms 2017 In: Bmc Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 17 Journal article (peer-reviewed)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.
6.	Appeltans, W., et al. (author) The Magnitude of Global Marine Species Diversity 2012 In: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 22:23, s. 2189-2202 Journal article (peer-reviewed)abstract Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are similar to 226,000 eukaryotic marine species described. More species were described in the past decade (similar to 20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are similar to 170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 +/- 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.
7.	Arslan, N., et al. (author) Aquatic Oligochaeta (Annelida) of Balıkdamı wetland (Turkey), with description of two new species of Phallodrilinae 2007 In: Biologia. - : Springer Science and Business Media LLC. - 0006-3088 .- 1336-9563. ; 62:3, s. 323-334 Journal article (peer-reviewed)abstract The Balıkdamı Wetland, an impoundment of the upper course of the Sakarya River located near Sivrihisar (Eskişehir, Central Anatolia), is one of the most important bird conservation areas in Turkey. This area also encompasses the mouth of the torrential Göksu Stream, which is partly hyporheic. During this study (2001–2003), 1,471 specimens representing 34 taxa of aquatic Oligochaeta were collected from the Balıkdamı Wetland. All the species identified are new records for Balıkdamı. Two species, Coralliodrilus amissus sp. n. and Gianius anatolicus sp. n., are new to science, and five species, Stylodrilus parvus (Hrabě et Černosvitov, 1927), Chaetogaster diastrophus (Gruithuisen, 1828), Peipsidrilus libanus (Giani et al., 1982), Tubifex acuticularis Martinez-Ansemil et Giani, 1983, and Epirodrilus moubayedi Giani et Martinez-Ansemil, 1983, are new records for Turkey. Two other species, Peipsidrilus libanus and Tubifex acuticularis, are re-described. The oligochaete fauna of the wetland was dominated by widely distributed tubificid taxa. The lumbriculid Stylodrilus parvus was the most abundant species in the Göksu stream. The two new phallodriline species are remarkable since most representatives of this subfamily live in the marine environment. Due to the species richness and diversity of Oligochaeta, as well as of several other animal groups, the Balıkdamı wetland area deserves conservation.
8.	Bergin, Claudia, et al. (author) Acquisition of a Novel Sulfur-Oxidizing Symbiont in the Gutless Marine Worm Inanidrilus exumae 2018 In: Applied and Environmental Microbiology. - : AMER SOC MICROBIOLOGY. - 0099-2240 .- 1098-5336. ; 84:7 Journal article (peer-reviewed)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.
9.	Blazejak, A., et al. (author) Coexistence of bacterial sulfide oxidizers, sulfate reducers, and spirochetes in a gutless worm (Oligochaeta) from the Peru margin 2005 In: Applied and Environmental Microbiology. - 0099-2240. ; 71:3, s. 1553-1561 Journal article (peer-reviewed)abstract Olavius crassitunicatus is a small symbiont-bearing worm that occurs at high abundance in oxygen-deficient sediments in the East Pacific Ocean. Using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization, we examined the diversity and phylogeny of bacterial symbionts in two geographically distant O. crassitunicatus populations (separated by 385 km) on the Peru margin (water depth, similar to 300 m). Five distinct bacterial phylotypes co-occurred in all specimens from both sites: two members of the gamma-Proteobacteria (Gamma 1 and 2 symbionts), two members of the delta-Proteobacteria (Delta I and 2 symbionts), and one spirochete. A sixth phylotype belonging to the delta-Proteobacteria (Delta 3 symbiont) was found in only one of the two host populations. Three of the O. crassitunicatus bacterial phylotypes are closely related to symbionts of other gutless oligochaete species; the Gamma 1 phylotype is closely related to sulfide-oxidizing symbionts of Olavius algarvensis, Olavius loisae, and Inanidrilus leukodermatus, the Delta 1 phylotype is closely related to sulfate-reducing symbionts of O . algarvensis, and the spirochete is closely related to spirochetal symbionts of O. loisae. In contrast, the Gamma 2 phylotype and the Delta 2 and 3 phylotypes belong to novel lineages that are not related to other bacterial symbionts. Such a phylogenetically diverse yet highly specific and stable association in which multiple bacterial phylotypes coexist within a single host has not been described previously for marine invertebrates.
10.	Blazejak, A., et al. (author) Phylogeny of 16S rRNA, ribulose 1,5-bisphosphate carboxylase/oxygenasem and adenosine 5’-phosphosulfate reductase genes from gamma- and alphaproteobacterial symbionts in gutless marine worms (Oligochaeta) from Bermuda and the Bahamas. 2006 In: Applied and Environmental Microbiology. - 0099-2240. ; 72:8, s. 5527-5536 Journal article (peer-reviewed)abstract Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluorescence in situ hybridization. As in all other gutless oligochaetes examined to date, I. leukodermatus and I. makropetalos harbor large, oval bacteria identified as Gamma 1 symbionts. The presence of genes coding for ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) and adenosine 5'-phosphosulfate reductase (aprA) supports earlier studies indicating that these symbionts are chemoautotrophic sulfur oxidizers. Alphaproteobacteria, previously identified only in the gutless oligochaete Olavius loisae from the southwest Pacific Ocean, coexist with the Gamma 1 symbionts in both I. leukodermatus and I. makropetalos, with the former harboring four and the latter two alphaproteobacterial phylotypes. The presence of these symbionts in hosts from such geographically distant oceans as the Atlantic and Pacific suggests that symbioses with alphaproteobacterial symbionts may be widespread in gutless oligochaetes. The high phylogenetic diversity of bacterial endosymbionts in two species of the genus Inanidrilus, previously known only from members of the genus Olavius, shows that the stable coexistence of multiple symbionts is a common feature in gutless oligochaetes.
11.	Bleidorn, Christoph, et al. (author) On the role of character loss in orbiniid phylogeny (Annelida): molecules vs. morphology 2009 In: Molecular Phylogenetics and Evolution. ; 52, s. 57-69 Journal article (peer-reviewed)
12.	Cook, D.G., et al. (author) Clitellata: Tubificids, Enchytraeids, and Randiellids (Oligochaetes) 2007 In: The Light & Smith Manual: Intertidal Invertebrates from Central California to Oregon.. - Berkeley and L.A. : University of California Press. - 9780520239395 ; , s. 298-303 Book chapter (other academic/artistic)
13.	Cook, David G., et al. (author) Oligochaeta 2023 In: The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon: Fourth Edition, Completely Revised and Expanded. - 9780520930438 ; , s. 298-303 Book chapter (other academic/artistic)
14.	Coulson, S. J., et al. (author) Introduction of invertebrates into the High Arctic via imported soils: the case of Barentsburg in the Svalbard 2013 In: Biological Invasions. - : Springer Science and Business Media LLC. - 1387-3547 .- 1573-1464. ; 15:1, s. 1-5 Journal article (peer-reviewed)abstract Forty six species of invertebrate were collected from the manure enriched imported soils below the abandoned cow sheds in the Russian mining town of Barentsburg, Svalbard. Of these, 11 (24 %) were new records for Svalbard, including Collembola, gamasid mites, Enchytraeidae and the first identified Lumbricidae. Many of the new records are species not frequently observed in the Arctic. It is hypothesized that these species arrived with the chernozem soils imported to Barentsburg for the greenhouses from central or southern European Russia, or with livestock. The observations presented here are the first records of human invertebrate introductions establishing in Svalbard outside of dwellings. It is not believed that the majority of new species records described present an immediate threat to the ecology of Svalbard but they may, especially Deuteraphorura variabilis, establish in the nutrient enriched floral communities beneath bird cliffs characteristic of Svalbard.
15.	Coulson, S. J., et al. (author) The invertebrate fauna of anthropogenic soils in the High-Arctic settlement of Barentsburg, Svalbard 2013 In: Polar Research. - : Norwegian Polar Institute. - 0800-0395 .- 1751-8369. ; 32 Journal article (peer-reviewed)abstract The terrestrial environment of the High Arctic consists of a mosaic of habitat types. In addition to the natural habitat diversity, various human-influenced types may occur. For the resident invertebrate fauna, these anthropogenic habitats may be either unusually favourable or detrimental. In the town of Barentsburg, Svalbard, soils were imported for the greenhouses from southern Russia. These soils were subsequently discarded outside the greenhouses and have become augmented with manure from the cowsheds. Both the greenhouse and the cowsheds are now derelict. This site represents an unusually nutrient-rich location with considerable development of organic soils, in stark contrast to the naturally forming organic soils in Svalbard, which are typically thin and nutrient poor. Few previous studies have examined the soil invertebrate communities of human-disturbed or -created habitats in the Arctic. In an often nutrient-poor terrestrial environment, it is unclear how the invertebrate fauna will react to such nutrient enhancement. In these soils, 46 species of invertebrates were determined. Eleven species have not been recorded from other habitats in Svalbard and are hence likely to have been introduced. The native species assemblage in the anthropogenic soils was not atypical for many natural sites in Svalbard. Despite the enriched organic soils and highly ameliorated winter temperature conditions, the soil invertebrate fauna biodiversity does not appear to be enhanced beyond the presence of certain probably introduced species.
16.	De Wit, Pierre, 1978, et al. (author) A preliminary molecular phylogeny of the enchytraeid genus Grania 2006 In: Poster presented at The 10th International symposium on Aquatic Oligochaeta, Wuhan, China 16-21 October 2006.. Conference paper (other academic/artistic)
17.	De Wit, Pierre, 1978, et al. (author) Grania (Annelida: Clitellata: Enchytraeidae) of the Great Barrier Reef, Australia, including four new species and a re-description of Grania trichaeta Jamieson, 1977 : Grania of the Great Barrier Reef 2009 In: Zootaxa. - 1175-5326. ; 2165, s. 16-38 Journal article (peer-reviewed)abstract This study describes the fauna of the marine enchytraeid genus Grania at two locations on the Australian Great Barrier Reef: Lizard and Heron Islands. Collections were made from 1979 to 2006, yielding four new species: Grania breviductus sp. n., Grania regina sp. n., Grania homochaeta sp. n. and Grania colorata sp. n.. A re-description of Grania trichaeta Jamieson, 1977 based on new material is also included, along with notes and amendments on G. hyperoadenia Coates, 1990 and G. integra Coates & Stacey, 1997, the two latter being recorded for the first time from eastern Australia. COI barcode sequences were obtained from G. trichaeta and G. colorata and deposited with information on voucher specimens in the Barcode of Life database and GenBank; the mean intraspecific variation is 1.66 % in both species, while the mean interspecific divergence is 25.54 %. There seem to be two phylogeographic elements represented in the Great Barrier Grania fauna; one tropical with phylogenetic affinities to species found in New Caledonia and Hong Kong, and one southern (manifested at the more southerly located Heron Island) with affinities to species found in Southern Australia, Tasmania and Antarctica.
18.	De Wit, Pierre, 1978, et al. (author) Intraspecific variation and phylogeny of Scandinavian species of Grania (Annelida: Clitellata: Enchytraeidae), with the discovery of a cryptic species. 2010 In: Journal of Zoological Systematics and Evolutionary Research. - 0947-5745. ; 48:4, s. 285-293 Journal article (peer-reviewed)abstract Individuals of five nominal species of Grania (Annelida: Clitellata: Enchytraeidae) were collected from locations in Sweden, Norway and France, for studies on the intraspecific variation at the Cytochrome Oxidase I (COI) locus of mitochondrial DNA and internal transcribed spacer (ITS) region of nuclear DNA. It was found that the previously described morphospecies in general contain low variation compared to the between-species variation in both loci. In one instance, however, an individual morphologically indistinguishable from G. ovitheca was found to be deviant and instead cluster with G. postclitellochaeta both by COI and ITS. We describe this individual as a new species: G. occulta sp.n. Furthermore, phylogenetic analyses were conducted, showing a close relationship between G. variochaeta, G. occulta, G. ovitheca and G. postclitellochaeta, as well as between G. pusilla and G. maricola. Using the results from the phylogenetic analyses, we discuss the evolution of morphological characters in Scandinavian species of Grania.
19.	De Wit, Pierre, 1978, et al. (author) Molecular evidence indicates that morphological characters are unsuitable to infer phylogeny of Grania 2009 In: Abstracts, 11th International Symposium on Aquatic Oligochaeta, Alanya, Turkey, 5-12 October 2009. Conference paper (peer-reviewed)
20.	De Wit, Pierre, 1978, et al. (author) Phylogeny and character evolution in Grania (Annelida, Clitellata) 2011 In: Zoologica Scripta. ; 40:5, s. 509-519 Journal article (peer-reviewed)
21.	De Wit, Pierre, 1978, et al. (author) Seven new species of Grania (Annelida: Clitellata: Enchytraeidae) from New Caledonia, South Pacific Ocean 2007 In: Zootaxa. - 1175-5326. ; 1426, s. 27-50 Journal article (peer-reviewed)abstract In meiofauna of the intertidal and subtidal zones (to 20 m depth) of New Caledonia seven species of the marine enchytraeid genus Grania were found, all of which were previously undescribed: G. novacaledonia sp.n., G. cinctura sp. n., G. galbina sp. n., G. curta sp. n., G. fustata sp. n., G. papillata sp. n. and G. fiscellata sp. n. On the basis of morphology, these new species seem to have a phylogenetic affinity to congeners in Australia and possibly Antarctica, although little is known about the enchytraeid fauna of the surrounding areas.
22.	De Wit, Pierre, 1978, et al. (author) Seven new species of Grania (Annelida: Clitellata: Enchytraeidae) from New Caledonia, South Pacific Ocean 2006 In: The Marine Biological Association - Third Annual Postgraduate Workshop Dublin, Ireland 3-5 maj. Conference paper (other academic/artistic)
23.	De Wit, Pierre, 1978, et al. (author) Ultrastructure of the body wall of three species of Grania (Annelida: Clitellata: Enchytraeidae) : Body wall ultrastructure of Grania 2011 In: Acta Zoologica. ; 92, s. 1-11 Journal article (peer-reviewed)abstract The body wall of three species of Grania, including the cuticle, epidermis and the musculature, are studied using TEM. The cuticle is similar to previously studied enchytraeids, with an orthogonal grid pattern of collagen fibers. This pattern is also seen in Crassiclitellata, which has been suggested as the sister taxon of Enchytraeidae. Variation of epicuticular and fiber zone patterns seen in Naididae (formerly Tubificidae and Naididae) seem to be lacking in Enchytraeidae. The fiber thickness, however, varies between Grania species and may be a phylogenetically informative character. The epidermis consists of supporting cells, secretory cells and sensory cells. Basal cells, typical for Crassiclitellata, were not observed. The clitellum of Grania seems to consist of two types of gland cells, which develop from regular epidermal tissue. It is possible that more cell types exist in different regions of the clitellum, however. The body wall musculature is arranged somewhat differently from that of closely related taxa; this refers to the reduction of circular and outer, triangular longitudinal muscle fibers, while the inner, ribbon-shaped longitudinal muscle fibers are well-developed. A search was conducted for the cause of the peculiar green coloration of Grania galbina De Wit and Erse´us 2007, and it was concluded that neither cyanobacteria nor epidermal pigment granules were present in the fixed material.
24.	Envall, Ida, et al. (author) Genetic and chaetal variation in Nais worms (Annelida, Clitellata, Naididae) 2012 In: Zoological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4082 .- 1096-3642. ; 165:3, s. 495-520 Journal article (peer-reviewed)abstract The genus Nais is a group of oligochaetous clitellates, common in eutrophic freshwater habitats. About 30 species are described. Species identification is based primarily on chaetal characters, which are often subtle, inconsistent, and even overlapping between nominal species. We investigated the correlation between genetic variation and chaetal morphology in this genus. Eighty-one individuals from Europe, North America, and China were included in the study. Seventy-five of these were preserved as vouchers. They were scrutinized with regard to chaetal morphology, and ten different morphotypes were identified. Three molecular markers, two mitochondrial (the COI gene and 16S rDNA) and one nuclear (the ITS region), were used to establish the genetic lineages in the material. Genetic variation was found to be largely congruent with chaetal character patterns. However, at least nine separately evolving lineages (all supported by mitochondrial as well as nuclear data) correspond to at most six nominal species. Four morphotypes/lineages are recognized as Nais barbata, Nais christinae, Nais elinguis, and Nais stolci, respectively, whereas five, or possibly more, lineages represent a morphological continuum covering the variation of the Nais communis/variabilis complex. Thus, cryptic speciation is revealed. Our results indicate that a taxonomic revision of the genus will be needed in the future.
25.	Envall, Ida, 1972-, et al. (author) Molecular evidence for the non-monophyletic status of Naidinae (Annelida, Clitellata, Tubificidae) 2006 In: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 40:2, s. 570-584 Journal article (peer-reviewed)abstract Naidinae (former Naididae) is a group of small aquatic clitellate annelids, common worldwide. In this study, we evaluated the phylogenetic status of Naidinae, and examined the phylogenetic relationships within the group. Sequence data from two mitochondrial genes (12S rDNA and 16S rDNA), and one nuclear gene (18S rDNA), were used. Sequences were obtained from 27 naidine species, 24 species from the other tubificid subfamilies, and five outgroup taxa. New sequences (in all 108) as well as GenBank data were used. The data were analysed by parsimony and Bayesian inference. The tree topologies emanating from the different analyses are congruent to a great extent. Naidinae is not found to be monophyletic. The naidine genus Pristina appears to be a derived group within a clade consisting of several genera (Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus) from another tubificid subfamily, Rhyacodrilinae. These results demonstrate the need for a taxonomic revision: either Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus should be included within Naidinae, or Pristina should be excluded from this subfamily. Monophyly of four out of six naidine genera represented by more than one species is supported: Chaetogaster, Dero, Paranais, and Pristina, respectively
26.	Envall, Ida, et al. (author) Ultrastructural investigation of coelomocytes in representatives of Naidinae and Rhyacodrilinae (Annelida, Clitellata, Tubificidae) 2008 In: Journal of Morphology. - : Wiley. - 0362-2525 .- 1097-4687. ; 269:9, s. 1157-1167 Journal article (peer-reviewed)abstract Various types of free-floating cells are found in the coelomic fluid of representatives of several annelid groups. The ultrastructure of these "coelomocytes," however, has been studied to a limited degree. In this study, we used a transmission electron microscope to investigate the coelomocytes in specimens of five species of Naidinae and three species of Rhyacodrilinae (all oligochaetous clitellates within the family Tubificidae). These were compared with each other and with previously described coelomocytes of representatives of other oligochaete taxa. Only one distinguishable coelomocyte type was found in the studied specimens: a round to oblong cell without pseudopodia or other appendages, primarily containing membrane-bound granules of varying electron density, a prominent network of rough endoplasmic reticulum, and free ribosomes. This type differs to a great extent from most of the previously described coelomocytes, but shows similarities to certain types found in members of Enchytraeidae and Megascolecidae. Although we noticed some variation, we did not find any ultrastructural characters in these cells obviously useful for phylogenetic studies within Tubificidae.
27.	Epp, L. S., et al. (author) New environmental metabarcodes for analysing soil DNA: potential for studying past and present ecosystems 2012 In: Molecular Ecology. - 0962-1083. ; 21:8, s. 1821-1833 Journal article (peer-reviewed)abstract Metabarcoding approaches use total and typically degraded DNA from environmental samples to analyse biotic assemblages and can potentially be carried out for any kinds of organisms in an ecosystem. These analyses rely on specific markers, here called metabarcodes, which should be optimized for taxonomic resolution, minimal bias in amplification of the target organism group and short sequence length. Using bioinformatic tools, we developed metabarcodes for several groups of organisms: fungi, bryophytes, enchytraeids, beetles and birds. The ability of these metabarcodes to amplify the target groups was systematically evaluated by (i) in silico PCRs using all standard sequences in the EMBL public database as templates, (ii) in vitro PCRs of DNA extracts from surface soil samples from a site in Varanger, northern Norway and (iii) in vitro PCRs of DNA extracts from permanently frozen sediment samples of late-Pleistocene age (similar to 16 00050 000 years bp) from two Siberian sites, Duvanny Yar and Main River. Comparison of the results from the in silico PCR with those obtained in vitro showed that the in silico approach offered a reliable estimate of the suitability of a marker. All target groups were detected in the environmental DNA, but we found large variation in the level of detection among the groups and between modern and ancient samples. Success rates for the Pleistocene samples were highest for fungal DNA, whereas bryophyte, beetle and bird sequences could also be retrieved, but to a much lesser degree. The metabarcoding approach has considerable potential for biodiversity screening of modern samples and also as a palaeoecological tool.
28.	Erséus, Christer, 1951, et al. (author) 18S rDNA phylogeny of Clitellata (Annelida). 2004 In: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 33:2, s. 187-196 Journal article (peer-reviewed)abstract The phylogeny of Clitellata was analysed using 18S rDNA sequences of a selection of species representing Hirudinida, Acanthobdellida, Branchiobdellida and 10 oligochaetous families. Eleven new 18S sequences of Capilloventridae (one), Haplotaxidae (one), Propappidae (one), Enchytraeidae (two), Lumbricidae (one), Almidae (one), Megascolecidae (two), Lumbriculidae (one), and Phreodrilidae (one) are reported and aligned together with corresponding sequences of 28 previously studied clitellate taxa. Twelve polychaete species were used as an outgroup. The analysis supports an earlier hypothesis based on morphological features that Capilloventridae represents a basal clade of Clitellata; in the 18S tree it shows a sister-group relationship to all other clitellates. The remaining clitellate taxa form a basal dichotomy, one clade containing Tubificidae (including the former ‘Naididae’), Phreodrilidae, Haplotaxidae, and Propappidae, the other clade with two subgroups: (1) Lumbriculidae together with all leech-like taxa (Acanthobdellida, Branchiobdellida and Hirudinida), and (2) Enchytraeidae together with a monophyletic group of all earthworms included in the study (Lumbricidae, Almidae and Megascolecidae). These earthworms are members of the taxon Crassiclitellata, the monophyly of which is thus supported by the data. The tree also shows support for the hypothesis that the first clitellates were aquatic. The position of the single species representing Haplotaxidae is not as basal as could have been expected from earlier morphology-based conclusions about the ancestral status of this family. However, if Haplotaxidae is indeed a paraphyletic assemblage of relict taxa, a higher number of representatives will be needed to resolve its exact relationships with the other clitellates.
29.	Erséus, Christer, 1951, et al. (author) 18S rDNA phylogeny of oligochaetous Clitellata [Abstract; 22nd Annual Meeting of the Willi Hennig Society] 2004 In: Cladistics. ; 20 Conference paper (other academic/artistic)
30.	Erséus, Christer, 1951 (author) A DNA-coding approach to the diversity of Swedish Earthworms (Lumbricidae) 2009 In: Poster, 11th International Symposium on Aquatic Oligochaeta, Alanya, Turkey, 5-12 October 2009. Conference paper (other academic/artistic)
31.	Erséus, Christer, 1951, et al. (author) A new marine species of Tubificoides (Annelida: Oligochaeta: Tubificidae) from Hawaii, U.S.A. 2005 In: Proceedings of the Biological Society of Washington. ; 118:2, s. 264-269 Journal article (peer-reviewed)abstract Tubificoides calvescentis is described from subtidal sediments near a sewage outfall at Sand Island, off Honolulu, Oahu, Hawaii. It is characterized by hair chaetae being restricted to preclitellar segments, small atria and spermathecae, and smooth, cylindrical, cuticular penis sheaths. Tubificoides bakeri Brinkhurst, 1985, known from the West coast of North America, appears to be closely related to the new species; its male genitalia are virtually identical to those of T. calvescentis. However, T. bakeri does not possess distinct cuticular papillae, which are evident in T. calvescentis, and it has more numerous chaetae and more slender spermatozeugmata than those of the new species. The paper also provides a nomenclaturally updated list of all marine oligochaetes reported from Hawaii.
32.	Erséus, Christer, 1951 (author) A new species, Olavius ulrikae (Annelida: Clitellata: Tubificidae), re-assessment of a Western Australian gutless marine worm 2008 In: Western Australian Museum. Records. - 0312-3162. ; 24, s. 195-198 Journal article (peer-reviewed)
33.	Erséus, Christer, 1951 (author) A possibly opportunistic clitellate annelid belonging to the genus Potamothrix (family Naididae) in the microbial ecosystems of the Frasassi caves (Italy) 2009 In: Abstracts, The Frasassi stygobionts and their sulfidic environment, A scientific conference and workshop organized by the Federazione Speleologica Marchigiana, and the Osservatorio Geologico di Coldigioca, Genga (AN), Italy, 10-13 September 2009. ; , s. 27-28 Conference paper (other academic/artistic)
34.	Erséus, Christer, 1951, et al. (author) Barcoding worms 2007 In: JMBA Global Marine Environment. ; 2007:6 Journal article (other academic/artistic)
35.	Erséus, Christer, 1951, et al. (author) Case 3305. TUBIFICIDAE Vejdovský, 1876 (Annelida, Clitellata): proposed precedence over NAIDIDAE Ehrenberg, 1828 2005 In: Bulletin of Zoological Nomenclature. ; 62:4, s. 226-231 Journal article (peer-reviewed)abstract The purpose of this application, under Article 23.9.3 of the Code, is to conserve the usage of the family-group name TUBIFICIDAE Vejdovský, 1876 for a well known group of aquatic oligochaetous clitellates. Following recent molecular studies it has been concluded that NAIDIDAE Ehrenberg, 1828 is a phylogenetic member of the taxon previously referred to as TUBIFICIDAE, implying that these two names are synonyms. Both names have long been used by aquatic biologists as associated with two functionally separated groups of worms. The junior name TUBIFICIDAE, with the famous Tubifex worm as its type, has been used for about 800 benthic species, which are burrowing or living interstitially in various limnic and marine sediments. The senior name NAIDIDAE, on the other hand, has been referred to about 175 species, most of which are epibenthic or epiphytic in freshwater habitats. It is proposed that the family-group name TUBIFICIDAE be given precedence over NAIDIDAE.
36.	Erséus, Christer, 1951, et al. (author) Case 3826 – Propappus Michaelsen, 1905 and PROPAPPIDAE Coates, 1986 (Annelida, Clitellata): proposed conservation by suppression of Propappus Seeley, 1888 (Vertebrata, Reptilia) 2021 In: The Bulletin of Zoological Nomenclature. - : The Bulletin of Zoological Nomenclature. - 0007-5167. ; 78:1, s. 17-25 Journal article (peer-reviewed)abstract conserve the well-used names Propappus Michaelsen, 1905 and Propapidae Coates, 1986 (Annelida) by suppression of the senior homonym Propappus Seeley, 1888 (Reptilia), a junior subjective synonym of Pareiasaurus Owen, 1876.
37.	Erséus, Christer, 1951, et al. (author) COI variation in Scandinavian marine species of Tubificoides (Annelida, Clitellata, Tubificidae). 2007 In: Journal of the Marine Biological Association of the United Kingdom. - 0025-3154. ; 87:5, s. 1121-1126 Journal article (peer-reviewed)
38.	Erséus, Christer, 1951, et al. (author) Cryptic speciation in clitellate model organisms 2009 In: Annelids in modern biology, Ed. Dan Shain. - Hoboken, New Jersey : Wiley-Blackwell. - 9780470344217 ; , s. 31-46 Book chapter (other academic/artistic)
39.	Erséus, Christer, 1951 (author) Cryptic speciation in common oligochaetes 2009 In: Abstracts, 11th International Symposium on Aquatic Oligochaeta, Alanya, Turkey, 5-12 October 2009. Conference paper (peer-reviewed)
40.	Erséus, Christer, 1951 (author) Cryptic speciation in marine oligochaetes revealed by DNA data 2008 In: Abstract, World Conference on Marine Biodiversity, Valencia, Spain, Nov 2008. Conference paper (other academic/artistic)
41.	Erséus, Christer, 1951, et al. (author) Gutless marine oligochaetes and their bacterial symbionts 2004 In: Abstracts, Henning XXIII "Phylogenetics and Evolutionary Biology", 23th meeting of the Willi Hennig Society, Paris, 18-23 July 2004. ; , s. 21-22 Conference paper (other academic/artistic)
42.	Erséus, Christer, 1951, et al. (author) Gutless marine oligochaetes and their bacterial symbionts [Abstract; 23rd Annual Meeting of the Willi Hennig Society] 2004 In: Cladistics. ; 20 Conference paper (other academic/artistic)
43.	Erséus, Christer, 1951 (author) Haplotaxis gordioides - oväntat fynd i Sverige av en sällsynt ringmask 2005 In: Fauna och Flora. ; 100, s. 42-43 Journal article (other academic/artistic)
44.	Erséus, Christer, 1951, et al. (author) ICZN rules - a farewell to Tubificidae (Annelida, Clitellata) 2008 In: Zootaxa. - 1175-5326. ; 1744, s. 66-68 Journal article (peer-reviewed)
45.	Erséus, Christer, 1951, et al. (author) Klättrande daggmaskar bifångst i Malaisefällor 2017 In: Fauna och flora. - 0014-8903. ; 112:2, s. 27-31 Journal article (other academic/artistic)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.
46.	Erséus, Christer, 1951, et al. (author) Marine Tubificidae (Annelida: Clitellata) of the Esperance area, Western Australia, Australia 2005 In: F.E. Wells, D.I. Walker and G.A. Kendrick (eds). The Marine Flora and Fauna of Esperance, Western Australia. - Perth : Western Australian Museum. - 1920843078 - 9781920843076 ; , s. 399-424 Book chapter (other academic/artistic)
47.	Erséus, Christer, 1951, et al. (author) Molecular data reveal a tropical freshwater origin of Naidinae (Annelida, Clitellata, Naididae) 2017 In: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 115, s. 115-127 Journal article (peer-reviewed)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.
48.	Erséus, Christer, 1951, et al. (author) Molecular phylogeny of Enchytraeidae (Annelida, Clitellata). 2010 In: Molecular Phylogenetics and Evolution. - 1055-7903. ; 57:2, s. 849-858 Journal article (peer-reviewed)abstract A multigene data set (12S, 16S, and COI mitochondrial DNA; 18S and 28S nuclear DNA) was analyzed by Bayesian inference to estimate the phylogeny of a sample of the clitellate family Enchytraeidae (86 species representing 14 nominal genera). Monophyly, as well as a basal dichotomy, of the family Enchytraeidae obtained maximum support, with one clade containing Hemienchytraeus and Achaeta, the other the remaining 12 genera analysed. The latter group is basally resolved in several well-supported clades. Lumbricillus and Grania are closely related. Bryodrilus, Oconnorella, Henlea and two species of Marionina (M. cf. riparia, and M. communis) form a well-supported clade. Cognettia is sister to Stercutus, and Cernosvitoviella sister to Mesenchytraeus, and the four together appear to be a monophyletic group. A large part of the taxonomically problematic Marionina appears to be a group not closely related to the type species (M. georgiana), and this group also includes Enchytronia. Further, this Marionina/Enchytronia group appears to be sister to a clade comprising the more or less littoral marine genera Stephensoniella and Enchytraeus. Hemifridericia, Buchholzia and Fridericia, the three genera characterized by two types of coelomocytes, also form a well-supported clade. The study corroborates most of the multi-species genera analysed (Cognettia, Cernosvitoviella, Mesenchytraeus, Oconnorella, Henlea, Enchytraeus, Grania, Buchholzia and Fridericia); only Lumbricillus and Marionina are non-monophyletic as currently defined.
49.	Erséus, Christer, 1951, et al. (author) New specific primers for amplification of the Internal Transcribed Spacer region in Clitellata (Annelida) 2017 In: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:23, s. 10421-10439 Journal article (peer-reviewed)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.
50.	Erséus, Christer, 1951, et al. (author) Phylogenomic analyses reveal a Palaeozoic radiation and support a freshwater origin for clitellate annelids 2020 In: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 49:5, s. 614-640 Journal article (peer-reviewed)abstract Clitellata is a major clade of Annelida comprising nearly all freshwater and terrestrial annelids as well as several marine species. We investigated clitellate phylogenetic relationships using transcriptomes sampled from 74 taxa (64 clitellates and 10 polychaetes), including multiple representatives of nearly all major clitellate higher taxa (Branchiobdellida, Capilloventridae, Crassiclitellata, Enchytraeidae, Haplotaxidae, Hirudinida, Lumbriculida, Moniligastridae, Naididae, Parvidrilidae, Phreodrilidae, Propappidae and Randiellidae). We used a number of filtered data matrices and phylogenetic analyses to examine the effects of data partitioning, missing data and compositional and branch-length heterogeneity and used the resulting phylogenies for divergence time estimation and ancestral habitat reconstructions. All analyses and filtering methods produced a consistent, strongly supported topology in which (a) Enchytraeidae, Hirudinida, Hirudinea (here, Branchiobdellida plus Hirudinida), Lumbriculida, Lumbriculata (Lumbriculida plus Hirudinea), Phreodrilidae and Naididae are monophyletic, (b) a Parvidrilidae + Randiellidae clade is sister to the rest of Clitellata, (c) Phreodrilidae is sister to Naididae, (d) Haplotaxidae is non-monophyletic, with some haplotaxids grouping with Crassiclitellata + Moniligastridae, (e) the Phreodrilidae + Naididae clade is sister to all other clitellates except Parvidrilidae + Randiellidae and Capilloventridae, and (f) Lumbriculata is sister to the Crassiclitellata + Moniligastridae + Haplotaxidae (in part) clade. Ancestral habitat reconstructions and divergence time analysis suggested that the most recent common ancestor of Clitellata lived in freshwater during the Devonian (419-359 million years ago) and that all major extant clitellate lineages arose over the next similar to 150 million years, with multiple lineages subsequently returning to marine habitats or invading land. This study provides a phylogenetic framework for further investigation of the geological, environmental and biotic forces and genomic changes that may have impacted clitellate evolution and enabled several major habitat transitions within this group.

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