| 1. |
- Anderberg, Arne A., et al.
(författare)
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Evolutionary relationships in the Asteraceae tribe Inuleae (incl. Plucheeae) evidenced by DNA sequences of ndhF; with notes on the systematic positions of some aberrant genera
- 2005
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Ingår i: Organisms Diversity & Evolution. - : Elsevier BV. - 1439-6092 .- 1618-1077. ; 5:2, s. 135-146
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Tidskriftsartikel (refereegranskat)abstract
- The phylogenetic relationships between the tribes Inuleae sensu stricto and Plucheeae are investigated by analysis of sequence data from the cpDNA gene ndhF. The delimitation between the two tribes is elucidated, and the systematic positions of a number of genera associated with these groups, i.e. genera with either aberrant morphological characters or a debated systematic position, are clarified. Together, the Inuleae and Plucheeae form a monophyletic group in which the majority of genera of Inuleae s.str. form one clade, and all the taxa from the Plucheeae together with the genera Antiphiona, Calostephane, Geigeria, Ondetia, Pechuel-loeschea, Pegolettia, and Iphionopsis from Inuleae s.str. form another. Members of the Plucheeae are nested with genera of the Inuleae s.str., and support for the Plucheeae clade is weak. Consequently, the latter cannot be maintained and the two groups are treated as one tribe, Inuleae, with the two subtribes Inulinae and Plucheinae. The genera Asteriscus, Chrysophthalmum, Inula, Laggera, Pentanema, Pluchea, and Pulicaria are demonstrated to be non-monophyletic. Cratystylis and Iphionopsis are found to belong to the same clade as the taxa of the former Plucheeae. Caesulia is shown to be a close relative of Duhaldea and Blumea of the Inuleae-Inulinae. The genera Callilepis and Zoutpansbergia belong to the major clade of the family that includes the tribes Heliantheae sensu lato and Inuleae (incl. Plucheeae), but their exact position remains unresolved. The genus Gymnarrhena is not part of the Inuleae, but is either part of the unresolved basal complex of the paraphyletic Cichorioideae, or sister to the entire Asteroideae.
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| 2. |
- Larsson, Karolina, et al.
(författare)
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DNA taxonomy of Swedish Catenulida (Platyhelminthes) and a phylogenetic framework for catenulid classification
- 2008
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Ingår i: Organisms Diversity & Evolution. - : Elsevier BV. - 1439-6092 .- 1618-1077. ; 8:5, s. 399-412
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Tidskriftsartikel (refereegranskat)abstract
- Specimens of Catenulida were collected at 34 localities in Sweden. We used 18S rDNA. 28S rDNA, ITS-5.8S. and cytochrome oxidase I (COI) nucleotide sequences to infer phylogeny from parsimony jackknifing and Bayesian analysis. Our dataset contained 74 ingroup terminals and 5111 characters. The results show it basal split between it clade consisting of the marine Retronectidae + the limnic Catenulidae. and it second clade consisting, of the limnic Stenostomidae. The hypothesis of the marine Retronectidae as the Sister group of the limnic Catenulida is rejected. The recently introduced genus Anokkostenostomum Norena, Damborenea & Brusa, 2005 results its non-monophyletic, and Suomina Marcus. 1945 its it group inside Catenula Duges, 1832. Therefore, we propose to render Anokkostenostomum a new junior synonym of Stenostomum Schmidt, 1848. and Suomina it new junior synonym of Catenula. Consequently, the new combinations Catenula evelinae (Marcus, 1945), Catenula sawayai (Marcus. 1945), and Catenula turgida (Zacharias. 1902) are proposed. and 14 species are returned to their original genus, Stenostomum. The molecular phylogenetic hypothesis is used to identify and discriminate catenulid species. In Our material. we found 12 species of Catenulida new to Sweden, and four Species new to science. all of which are distinguishable by morphological characters.
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| 3. |
- Larsson, Karolina, et al.
(författare)
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Phylogeny of Catenulida and support for Platyhelminthes
- 2008
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Ingår i: Organisms Diversity & Evolution. - : Elsevier BV. - 1439-6092 .- 1618-1077. ; 8:5, s. 378-387
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Tidskriftsartikel (refereegranskat)abstract
- Molecular studies have shown that Platyhelminthes is polyphyletic, placing Rhabditophora within Lophotrochozoa, whereas Acoela and Nemertodermatida are separate early bilaterian branches. However, there has been little evidence to support the position of Catenulida, a group that was traditionally classified within Platyhelminthes. In Ehlers' pioneering cladistic system of the Platyhelminthes they were placed as the earliest clade. Other morphologists have considered the Catenulida as an early bilaterian clade separate from Rhabditophora, a position that was supported in an early molecular study. Subsequent molecular phylogenetic studies, which placed Catenulida as the sister group of Rhabditophora with no or low branch support, included 18S rDNA data from only one or two catenulid species. The aims of the present study were (1) to test the putative sister-group relationship of Catenulida and Rhabditophora by improving the taxon sampling of molecular data spanning a larger part of catenulid taxonomic diversity and (2) to provide a phylogenetic framework for the systematization of Catenulida. Twelve catenulid species were sampled around Sweden. Both the 18S rDNA gene and the 28S rDNA gene were sequenced and analysed in a Metazoa-wide data set within parsimony and Bayesian frameworks. The results unambiguously support Catenulida as the sister group of Rhabditophora within Lophotrochozoa. Parsimony-based inferences about the common ancestor of Catenulida and Rhabditophora are presented. A definition of the name Platyhelminthes is suggested.
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| 4. |
- Obst, Matthias, 1974, et al.
(författare)
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A new species of Cycliophora from the mouthparts of the American lobster, Homarus americanus (Nephropidae, Decapoda)
- 2006
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Ingår i: Organisms Diversity and Evolution. - : Elsevier BV. - 1439-6092 .- 1618-1077. ; 6:2, s. 83-97
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Tidskriftsartikel (refereegranskat)abstract
- The present study describes a new species of Cycliophora with the aid of light- and electron microscopy. The animals live attached or free-living on the mouth appendages of the American lobster, Homarus americanus. Individuals occur in dense clusters of up to several thousand individuals. The new species is named Symbion americanus sp. nov. according to the name of its host; it can be distinguished from the previously described species Symbion pandora by the presence of a posterior pair of retractable tubular appendages or toes in the Prometheus larva. Morphological variation among cycliophorans on H. americanus collected in different localities seems to be high. In several sexual populations of S. americanus, older feeding individuals with a female typically have 5-13 rings of cuticular scars and a thicker cuticle. Moreover, attached Prometheus larvae frequently contain three males, chordoid cysts possess a distal appendix, and chordoid larval morphology varies among localities. These differences in morphology might indicate the existence of cryptic species. The presence of toes in the Prometheus larva could support a cycliophoran relationship with rotiferan taxa, although additional ultrastructural studies are needed. Considering that the genus Homarus is at least 60 My years old, and with regard to its history of speciation, it seems possible that the two Symbion species separated during the Pleistocene. © 2005 Gesellschaft für Biologische Systematik.
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| 5. |
- Eriksson, Robert, et al.
(författare)
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Genetic evidence of phenotypic polymorphism in the aeolid nudibranch Flabellina verrucosa (M. Sars, 1829) (Opisthobranchia : Nudibranchia)
- 2006
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Ingår i: Organisms Diversity & Evolution. - : Elsevier BV. - 1439-6092. ; 6:1, s. 71-76
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Tidskriftsartikel (refereegranskat)abstract
- The conspecificity of two forms of Flabellina verrucosa (M. Sars, 1829), one form with short and one with long cerata, was tested by sequencing the mitochondrial COI and the nuclear 5.8S-ITS2 genes. We could not establish any genetic differences between the two forms and conclude that they belong to the same species. Thus, Flabellina verrucosa is polymorphic in ceratum length. (c) 2005 Gesellschaft fur Biologische Systematik. Published by Elsevier GmbH. All rights reserved.
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| 6. |
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| 7. |
- Giere, O., et al.
(författare)
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Questa (Annelida, Polychaeta, Orbiniidae) from Pacific regions – new species and a reassessment of the genus Periquesta
- 2008
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Ingår i: Organisms Diversity & Evolution. - : Elsevier BV. - 1439-6092. ; 7:4, s. 304-319
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Tidskriftsartikel (refereegranskat)abstract
- On the basis of new material from various Pacific regions we critically evaluate the characters for the taxonomy of the genus Questa and the former Questidae, a taxon now concluded to be a lineage within the family Orbiniidae. Two new species, Questa retrospermatica sp. n. from Hawaii (with similar forms also from New Caledonia and China), and Questa fijiensis sp. n. from Fiji, are described, and the morphological character patterns and phylogeny of the genus are revisited on the basis of a cladistic analysis. The finding of Hawaiian material of a new species, Levinsenia hawaiiensis sp. n., similar to Periquesta canariensis Brito & Nunez, 2002 (=Levinsenia canariensis comb. n.), challenges the view that Periquesta Brito & Nunez, 2002 is closely related to Questa; rather, it belongs to Paraonidae as a junior synonym of Levinsenia Mesnil, 1897.
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