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| 2. |
- Leidenberger, Sonja, et al.
(författare)
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Data on three Baltic species of Corynosoma Lühe, 1905 (Acanthocephala: Polymorphidae) from Baltic grey (Halichoerus grypus) and ringed seals (Pusa hispida)
- 2020
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Ingår i: Dryad. ; v3, s. 1-9
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Annan publikationabstract
- We analyzed Baltic Corynosoma material (C. magdaleni Montreuil, 1958, C. semerme (Forssell, 1904) Lühe, 1911 and C. strumosum (Rudolphi, 1802; Lühe, 1904) from grey (Halichoerus grypus ) and ringed seals (Pusa hispida ) for the variation of hook morphology and for finding possible morphotypes, by using the proboscis profiler (Wayland 2010) and Meristogram (Wayland 2016).
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| 3. |
- Leidenberger, Sonja, et al.
(författare)
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Host records and geographical distribution of Corynosoma magdaleni, C. semerme and C. strumosum (Acanthocephala: Polymorphidae)
- 2020
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Ingår i: Biodiversity Data Journal. - : Pensoft Publishers. - 1314-2836 .- 1314-2828. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- A literature survey was conducted to investigate the host and geographical distribution patterns of three Corynosoma species (Acanthocephala: Polymorphidae), viz. C. magdaleni, C. semerme and C. strumosum. All three species appear to be restricted to the Northern Hemisphere. Occurrence records of C. magdaleni are limited to the Northern Atlantic coasts, while C. semerme has a circumpolar distribution. The geographical range of Corynosoma strumosum encompasses the distributions of the other two species, but also extends into warmer southern regions. Some Corynosoma populations are living with their definitive hosts in very isolated locations, such as in the brackish Baltic Sea or different freshwater lakes (e.g. Lake Saimaa). All three species have a heteroxenous life cycle, comprising a peracaridan intermediate host, a fish paratenic host and a mammalian definitive host. Occasionally, an acanthocephalan may enter an accidental host, from which it is unable to complete its life cycle. The host records reported here are categorised by type, i.e. intermediate, paratenic, definitive or accidental. While most of the definitive hosts are shared amongst the three Corynosoma species, C. strumosum showed the broadest range of paratenic hosts, which reflects its more extensive geographical distribution. One aim of this study and extensive literature summary is to guide future sampling efforts therewith contribute to throw more light on the on-going species and morphotype discussion for this interesting parasite species.
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| 4. |
- Kånneby, Tobias, 1981-
(författare)
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Gastrotricha of Sweden - Biodiversity and Phylogeny
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Gastrotricha are small aquatic invertebrates with approximately 770 known species. The group has a cosmopolitan distribution and is currently classified into two orders, Chaetonotida and Macrodasyida. The gastrotrich fauna of Sweden is poorly known: a couple of years ago only 29 species had been reported. In Paper I, III, and IV, 5 freshwater species new to science are described. In total 56 species have been recorded for the first time in Sweden during the course of this thesis. Common species with a cosmopolitan distribution, e. g. Chaetonotus hystrix and Lepidodermella squamata, as well as rarer species, e. g. Haltidytes crassus, Ichthydium diacanthum and Stylochaeta scirtetica, are reported. In Paper II molecular data is used to infer phylogenetic relationships within the morphologically very diverse marine family Thaumastodermatidae (Macrodasyida). Results give high support for monophyly of Thaumastodermatidae and also the subfamilies Diplodasyinae and Thaumastodermatinae. In Paper III the hypothesis of cryptic speciation is tested in widely distributed freshwater gastrotrichs. Heterolepidoderma ocellatum f. sphagnophilum is raised to species under the name H. acidophilum n. sp. The results indicate that L. squamata may be a complex of at least two species. In Paper III and V the phylogeny of Chaetonotidae (Chaetonotida), the largest family within Gastrotricha, is inferred. The group suffers from a troubled taxonomy and is hypothesized to be non-monophyletic. Results show that members of Dasydytidae are nested within the group. Since only 3 of 17 sampled genera are monophyletic, it is hypothesized that the cuticular structures used in current classification do not reflect phylogenetic relationships. The phylogenetic hypothesis generated in Paper V indicates a marine origin of the predominantly limnic Chaetonotidae with a subsequent secondary invasion to marine environments of some taxa.
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| 5. |
- Leidenberger, Sonja, et al.
(författare)
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Morphological observations on three Baltic species of Corynosoma Lühe, 1905 (Acanthocephala, Polymorphidae)
- 2019
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 514, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Necropsies of Baltic grey (Halichoerus grypus) and ringed seals (Pusa hispida) presented a rare opportunity to study their acanthocephalan fauna. Both species hosted adults of three species of the genus Corynosoma Lühe, 1904, namely C. magdaleni Montreuil, 1958, C. semerme (Forsell, 1904) Lühe 1911 and C. strumosum (Rudolphi, 1802) Lühe 1904. A comparative morphological analysis of these three species of Corynosoma, combining both light and scanning electron microscopy, was performed for the first time. Sexual dimorphism in the size and shape of the trunk was observed in both C. magdaleni and C. semerme, but there was insufficient material to investigate this phenomenon in C. strumosum. Genital spines were not observed in any of the female acanthocephalans. Three possible explanations for the presence of genital spines in some females, but not others are (i) cryptic speciation, (ii) phenotypic variation and (iii) loss by extraction or shearing when the copulatory cap is released. Copulatory caps were observed on female C. semerme. The size and morphology showed considerable variability and all caps were strongly autofluoresecent.
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| 6. |
- Sven, Boström, et al.
(författare)
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Descriptions of species of Acrobeles von Linstow, 1877 (Nematoda, Rhabditida, Cephalobidae) from Kelso Dunes, Mojave National Preserve, California, USA
- 2019
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4651, s. 330-350
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Tidskriftsartikel (refereegranskat)abstract
- Populations of three rare species of the genus Acrobeles are described from the Kelso Dunes area, Mojave National Preserve, southern California. One population is identified as belonging to A. undulatus and is compared with the type population from Venezuela and one population from Iran. Males of this species are described for the first time. Another population identified as belonging to A. ornatus is compared with the type population from Colorado, USA. Specimens identified as belonging to A. dimorphus are compared with the type population from Namibia. Descriptions of the new material add morphological data important for species identification, broaden the diagnosis of Acrobeles and increase the distribution patterns of these three species.
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| 7. |
- Ahmed, Mohammed, et al.
(författare)
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Revision of the genus Cobbionema Filipjev, 1922 (Nematoda, Chromadorida, Selachinematidae)
- 2020
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 702, s. 1-34
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the genus Cobbionema Filipjev, 1922 in Sweden with the description of four species and a revision of the genus. Cobbionema acrocerca Filipjev, 1922 is relatively small in size, with a tail that has a conical proximal and a digitate distal section. Cobbionema cylindrolaimoides Schuurmans Stekhoven, 1950 is similar to C. acrocerca in most characters except having a larger body size and heavily cuticularized mandibles. Cobbionema brevispicula sp. nov. is characterised by short spicules and a conoid tail. Cobbionema acuminata sp. nov. is characterised by a long two-part spicule, a conical tail and three (one mid dorsal and two ventrosublateral) sharply pointed tines in the anterior chamber of the stoma that are located more anterior than in all the other species. We also present a molecular phylogeny of the family based on the nearly full-length 18S and the D2-D3 expansion segment of the 28S rRNA genes. Maximum Likelihood and Bayesian trees inferred from both genes strongly support a clade that included Cobbionema, Demonema Cobb, 1894 and Halichoanolaimus de Man, 1888 and another clade with Gammanema Cobb, 1920 and Latronema Wieser, 1954 nested together. None of the trees supported the monophyly of the subfamilies Choniolaiminae and Selachinematinae.
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| 8. |
- Boström, Sven, et al.
(författare)
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Description of a new species of Paracrobeles Heyns, 1968 (Nematoda, Rhabditida, Cephalobidae) from Kelso Dunes, Mojave National Preserve, California, USA
- 2015
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 117, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- A new species of Paracrobeles, P. kelsodunensis sp. nov. is described from the Kelso Dunes area, Mojave National Preserve, southern California. Paracrobeles kelsodunensis sp. nov. is particularly characterised by a body length of 469–626 μm in females and 463–569 μm in males; lateral field with four incisures, extending almost to tail terminus; three pairs of asymmetrical lips, separated by U-shaped primary axils with two long guarding processes, each lip usually with four tines along its margin; three long labial probolae, deeply bifurcated, with slender prongs without tines; metastegostom with a strong anteriorly directed dorsal tooth; pharyngeal corpus anteriorly spindle-shaped, posteriorly elongate bulbous with dilated lumen; spermatheca 24–87 μm long; postvulval uterine sac 60–133 μm long; vulva in a sunken area; spicules 33–38 μm long; and male tail with a 5–8 μm long mucro. The generic diagnosis is emended on the basis of recently described species and a key to the species of Paracrobeles is provided.
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| 9. |
- Boström, Sven, et al.
(författare)
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Description of Drilocephalobus moldavicus Lisetskaya,1968 (Rhabditida: Osstellidae) from Kelso Dunes, Mojave National Reserve, California,USA
- 2018
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 4514:3, s. 438-444
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Tidskriftsartikel (refereegranskat)abstract
- Specimens of Drilocephalobus moldavicus are described from the Kelso Dunes area, Mojave National Preserve, southern California. This is the first record of the genus in North America. The specimens of this population are characterized by a body length of 322–417 µm in females and 403 µm in the male; cuticle finely annulated; lateral field with five incisures, extending to phasmid and two incisures extending almost to tail terminus in both sexes; lip region helmet-shaped, offset from body contour; lips amalgamated; stoma with thin walls lacking sclerotizations; pharynx without distinct divisions, cylindrical, widening slightly at about 1/3 of its length and basally, without valves; spermatheca 14–19 µm long; postvulval uterine sac 25–27 µm long; spicules 23 µm long; and female tail conoid-elongate with rounded terminus.
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| 10. |
- Boström, Sven, et al.
(författare)
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Descriptions of species of Stegelleta Thorne, 1938 (Nematoda, Rhabditida, Cephalobidae) from California, New Zealand and Senegal, and a revision of the genus
- 2014
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 87, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Populations of Stegelleta are described from California, New Zealand and Senegal. An amphimictic population from California is identified as belonging to S. incisa and compared with type specimens from Utah and an amphimictic population from Italy. One population from New Zealand is close to S. incisa but considered to represent a new species, Stegelleta laterocornuta sp. nov. It is particularly characterised by a 379–512 μm long body in females and 365–476 μm in males; cuticle divided into 16 rows of blocks at midbody (excluding lateral field); lateral field with four incisures; three pairs of asymmetrical lips, U-shaped primary axils without guarding processes, each lip asymmetrically rectangular with a smooth margin, only lateral lips have slender acute tines; three labial probolae, bifurcated at half of their length; vulva without flap; spermatheca 17–31 μm long; postuterine sac 7–24 μm long; spicules 21.5–23.5 μm long. Other specimens from New Zealand are identified as belonging to S. tuarua. A parthenogenetic population from Senegal is identified as belonging to S. ophioglossa and compared with type specimens from Mongolia and records of several other populations of S. ophioglossa. The generic diagnosis is emended and a key to the species of Stegelleta is provided.
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