| 1. |
- Boström, Sven, et al.
(författare)
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The Swedish marine nematologist Carl Allgén (1886–1960): a bio-bibliography and his collection
- 2017
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4232:4, s. 451-490
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish marine nematologist Carl Allgén (1886–1960) published 185 scientific papers on parasitic, terrestrial, limnic and especially marine nematodes between 1921 and 1960. Among them are also some papers on species of suctorians found mostly on desmodorid nematodes. He described about 70 new genera and over 800 new species and subspecies of nematodes. Allgén left a large collection of nematodes to the Swedish Museum of Natural History in Stockholm and it is now deposited in the invertebrate collection of the Zoology department. The collection comprises about 4500 slides in total, with about 310 slides containing type specimens collected from the Arctic to Antarctica. Allgén’s publications have to a large extent been ignored by scientists working on marine nematodes, likely because of the poor quality of many of his species descriptions. The authors want to remind the scientific community about the existence of Allgén's collection, its availability for study and its importance for nematode taxonomy and systematics. A complete list of Allgén’s publications, a list of all species described by him, and a list of type material available is presented.
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| 2. |
- Haenel, Quiterie, et al.
(författare)
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NGS-based biodiversity and community structure analysis of meiofaunal eukaryotes in shell sand from Hållö island, Smögen, and soft mud from Gullmarn Fjord, Sweden
- 2017
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Ingår i: Biodiversity Data Journal. - : Oleksandr Holovachov. - 1314-2828 .- 1314-2836. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- © Haenel Q et al. Aim: The aim of this study was to assess the biodiversity and community structure of Swedish meiofaunal eukaryotes using metabarcoding. To validate the reliability of the metabarcoding approach, we compare the taxonomic resolution obtained using the mitochondrial cytochrome oxidase 1 (COI) 'mini-barcode' and nuclear 18S small ribosomal subunit (18S) V1-V2 region, with traditional morphology-based identification of Xenacoelomorpha and Nematoda. Location: 30 samples were analysed from two ecologically distinct locations along the west coast of Sweden. 18 replicate samples of coarse shell sand were collected along the northeastern side of Hållö island near Smögen, while 12 replicate samples of soft mud were collected in the Gullmarn Fjord near Lysekil.
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| 3. |
- Holovachov, Oleksandr
(författare)
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Belgopeltula belgica (Vincx & Gourbault, 1992) gen. et comb. nov. and Mudwigglus micramphidium sp. nov. from the west coast of Sweden, and reappraisal of the genus Pseudaraeolaimus Chitwood, 1951 (Nematoda: Araeolaimida: Diplopeltidae)
- 2017
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 383, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- Two species of the nematode family Diplopeltidae are described from Skagerrak. The new genus Belgopeltula gen. nov. is proposed for Diplopeltula belgica Vincx & Gourbault, 1992 and is characterised by: amphidial fovea circular in female and double-loop-shaped in male; excretory pore located at the level of cephalic setae bases; oral opening on the dorsal side of the body; pharynx subdivided into strongly muscularised fusiform corpus and weakly muscularised narrow and long postcorpus; female didelphic with antidromously reflexed ovaries; supplements absent. Mudwigglus micramphidium sp. nov. is characterised by: a body of 0.6 mm long; cephalic sensilla 1.5 µm long; amphidial fovea loop-shaped, 8 µm long and 3.5 µm wide; gymnostom without cuticularised ring; tail elongate conoid, with subcylindrical distal part; terminal setae absent; spicules 15 µm long; gubernaculum present; two midventral precloacal setae. It is distinguished from M. macramphidium Leduc, 2013 in having shorter amphidial fovea, shorter spicules and presence of two precloacal setae. Redescription of Diplopeltis cylindricauda Allgén, 1932 is provided based on type material. Diplopeltula minuta Vitiello, 1972 is transferred to the genus Mudwigglus Leduc, 2013. Diplopeltis cylindricauda Allgén, 1932, Diplopeltula laminata Vitiello, 1972 and Diplopeltula cassidaignensis Vitiello, 1972 are transferred to the genus Pseudaraeolaimus Chitwood, 1951.
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| 4. |
- Holovachov, Oleksandr, et al.
(författare)
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Taxonomy assignment approach determines the efficiency of identification of OTUs in marine nematodes
- 2017
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 The Authors. Precision and reliability of barcode-based biodiversity assessment can be affected at several steps during acquisition and analysis of data. Identification of operational taxonomic units (OTUs) is one of the crucial steps in the process and can be accomplished using several different approaches, namely, alignment-based, probabilistic, tree-based and phylogenybased. The number of identified sequences in the reference databases affects the precision of identification. This paper compares the identification of marine nematode OTUs using alignment-based, tree-based and phylogeny-based approaches. Because the nematode reference dataset is limited in its taxonomic scope, OTUs can only be assigned to higher taxonomic categories, families. The phylogeny-based approach using the evolutionary placement algorithm provided the largest number of positively assigned OTUs and was least affected by erroneous sequences and limitations of reference data, compared to alignment-based and tree-based approaches.
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| 5. |
- Holovachov, Oleksandr
(författare)
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The choice of taxonomy assignment approach has strong impact on the efficiency of identification of OTUs in marine nematodes
- 2017
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Precision and reliability of barcode-based biodiversity assessment can be affected at several steps during acquisition and analysis of data. Identification of operational taxonomic units (OTUs) is one of the crucial steps in the process and can be accomplished using several different approaches, namely, alignment-based, probabilistic, tree-based and phylogeny-based. The number of identified sequences in the reference databases affects the precision of identification. This paper compares the identification of marine nematode OTUs using alignment-based, tree-based and phylogeny-based approaches. Because the nematode reference dataset is limited in its taxonomic scope, OTUs can only be assigned to higher taxonomic categories, families. The phylogeny-based approach using the evolutionary placement algorithm provided the largest number of positively assigned OTUs and was least affected by erroneous sequences and limitations of reference data, compared to alignment-based and tree-based approaches.
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| 6. |
- Holovachov, Oleksandr, et al.
(författare)
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Three new and five known species of Diplopeltoides Gerlach, 1962 (Nematoda, Diplopeltoididae) from Sweden, and a revision of the genus
- 2017
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 369, s. 1-35
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Tidskriftsartikel (refereegranskat)abstract
- Eight species of Diplopeltoides are described from the Swedish west coast. Diplopeltoides suecicus sp. nov. has the cuticle with longitudinal striation visible only under SEM; cuticular plate underlying the cephalic cuticle around the amphid present; cephalic sensilla 4–6 µm long; amphid an inverted U-shape; wide space between amphidial branches areolated; spicules 27–31 µm long; gubernaculum with caudal apophysis. Diplopeltoides longicaudatus sp. nov. is characterized by a cuticle without longitudinal striation; cuticular plate underlying cephalic cuticle around amphid present; cephalic sensilla 13 µm long; amphid an inverted U-shape; narrow space between amphidial branches not ornamented; spicules unequal in size, 27–31 µm long; gubernaculum absent; midventral precloacal cuticular ridge present. D. grandis sp. nov. is characterized by a cuticle with longitudinal striation; cuticular plate underlying cephalic cuticle around amphid present; cephalic sensilla 18.5 µm long; amphid an inverted U-shape; wide space between amphidial branches punctate. The following taxonomic changes are proposed: Diplopeltoides asetosus (Juario, 1974) comb. nov., Diplopeltoides botulus (Wieser, 1959) comb. nov., Diplopeltoides bulbosus (Vitiello, 1972) comb. nov., Diplopeltoides lucanicus (Boucher & Helléouët, 1977) comb. nov., Diplopeltoides pumilus (Vincx & Gourbault, 1992) comb. nov. and Diplopeltoides striatus (Gerlach, 1956) comb. nov. Diplopeltoides holovachovi Fadeeva & Mordukhovich, 2013 is synonymised with Diplopeltoides pumilus comb. nov. An updated key to the species of Diplopeltoides is provided.
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| 7. |
- Nermut, Jiri
(författare)
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Alloionema californicum Nermuť, Půža, Mráček & Lewis, 2016 is a junior synonym of Alloionema similis Holovachov, Boström, Tandingan De Ley, Mc Donnell, Alvarado, Paine & De Ley, 2016 (Nematoda: Alloionematidae)
- 2017
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4324:2, s. 378-384
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Tidskriftsartikel (refereegranskat)abstract
- The genus Alloionema (Rhabditida: Alloionematidae) currently includes three nominal species—the type species, Alloionema appendiculatum, and two recently described species: A. similis and A. californicum. Comparison of morphological, molecular and ecological characters demonstrates that A. similis and A. californicum belong to the same species, providing support for their synonymization, as proposed in this publication.
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