02800nas a2200157   4500008004100000022001400041245013400055210006900189260001500258520221200273100002802485700003402513700002402547700002202571856004902593       2013                        ENG d  a1095-951300aPhylogenetic relationship among genera of Polymorphidae (Acanthocephala), inferred from nuclear and mitochondrial gene sequences.0 aPhylogenetic relationship among genera of Polymorphidae Acanthoc  c2013 Apr 63 a<p>Acanthocephalans of the family Polymorphidae Meyer, 1931 are obligate endoparasites with complex life cycles. These worms use vertebrates (marine mammals, fish-eating birds and waterfowl) as definitive hosts and invertebrates (amphipods, decapods and euphausiids) as intermediate hosts to complete their life cycle. Polymorphidae has a wordwide distribution, containing 12 genera, with approximately 127 species. The family is diagnosed by having a spinose trunk, bulbose proboscis, double-walled proboscis receptacle, and usually four to eight tubular cement glands. To conduct a phylogenetic analysis, in the current study sequences of the small (18S) and large-subunit (28S) ribosomal RNA, and cytochrome c oxidase subunit 1 (cox 1) were generated for 27 taxa representing 10 of 12 genera of Polymorphidae, plus three additional species of acanthocephalans that were used as outgroups. Maximum likelihood (ML), maximum parsimony (MP), and Bayesian analyses were conducted on a combined nuclear rRNA (18S+28S) data set and on a concatenated dataset of nuclear plus one mitochondrial gene (18S+28S+cox 1). Phylogenetic analyses inferred with the concatenated dataset of three genes support the monophyly of nine genera (Andracantha, Corynosoma, Bolbosoma, Profilicollis, Pseudocorynosoma, Southwellina, Arhythmorhynchus, Hexaglandula and Ibirhynchus). However, the four sampled species of Polymorphus were nested within several clades, indicating that these species do not share a common ancestor, requiring further taxonomic revision using phylogenetic systematics, and reexamination of morphological and ecological data. By mapping definitive and intermediate host association onto the resulting cladogram, we observe that aquatic birds were the ancestral definitive hosts for the family with a secondary colonization and diversification to marine mammals. Whereas amphipods were ancestral intermediate hosts and that the association with decapods represent episodes of secondary colonization that arose several times during the evolutionary history of the family. Our results are useful to start testing hypothesis about the evolutionary history of this highly diverse family of acanthocephalans.</p>1 aGarcía-Varela, Martín1 ade León, Gerardo, Pérez-Pon1 aAznar, Francisco, J1 aNadler, Steven, A  uhttps://acanthocephala.myspecies.info/node/702572nas a2200361   4500008004100000022001400041245013100055210006900186260001300255300001000268490000700278520147700285653001901762653001201781653001801793653002501811653002301836653001501859653002601874653002501900653001401925653001701939653002701956100001901983700003202002700002402034700002102058700002102079700002102100700001902121700002002140856005002160       2013                        eng d  a1095-951300aPhylogenetic analyses of endoparasitic Acanthocephala based on mitochondrial genomes suggest secondary loss of sensory organs.0 aPhylogenetic analyses of endoparasitic Acanthocephala based on m  c2013 Jan  a182-90 v663 a<p>The metazoan taxon Syndermata (Monogononta, Bdelloidea, Seisonidea, Acanthocephala) comprises species with vastly different lifestyles. The focus of this study is on the phylogeny within the syndermatan subtaxon Acanthocephala (thorny-headed worms, obligate endoparasites). In order to investigate the controversially discussed phylogenetic relationships of acanthocephalan subtaxa we have sequenced the mitochondrial (mt) genomes of Echinorhynchus truttae (Palaeacanthocephala), Paratenuisentis ambiguus (Eoacanthocephala), Macracanthorhynchus hirudinaceus (Archiacanthocephala), and Philodina citrina (Bdelloidea). In doing so, we present the largest molecular phylogenetic dataset so far for this question comprising all major subgroups of Acanthocephala. Alongside with publicly available mt genome data of four additional syndermatans as well as 18 other lophotrochozoan (spiralian) taxa and one outgroup representative, the derived protein-coding sequences were used for Maximum Likelihood as well as Bayesian phylogenetic analyses. We achieved entirely congruent results, whereupon monophyletic Archiacanthocephala represent the sister taxon of a clade comprising Eoacanthocephala and monophyletic Palaeacanthocephala (Echinorhynchida). This topology suggests the secondary loss of lateral sensory organs (sensory pores) within Palaeacanthocephala and is further in line with the emergence of apical sensory organs in the stem lineage of Archiacanthocephala.</p>10aAcanthocephala10aAnimals10aBayes Theorem10aBiological Evolution10aDNA, Mitochondrial10aGene Order10aGenome, Mitochondrial10aLikelihood Functions10aPhylogeny10aSense Organs10aSequence Analysis, DNA1 aWeber, Mathias1 aWey-Fabrizius, Alexandra, R1 aPodsiadlowski, Lars1 aWitek, Alexander1 aSchill, Ralph, O1 aSugár, László1 aHerlyn, Holger1 aHankeln, Thomas  uhttps://acanthocephala.myspecies.info/node/12