PHYLOGENETIC RELATIONSHIPS OF PALAEACANTHOCEPHALA (ACANTHOCEPHALA) INFERRED FROM SSU AND LSU rDNA GENE SEQUENCES

• Published in: The Journal of parasitology Vol. 91; no. 6; pp. 1401 - 1409
• Main Authors: García-Varela, Martín, Nadler, Steven A
• Format: Journal Article
• Language: English
• Published: Lawrence, KS American Society of Parasitologists 01.12.2005; Allen Press Inc
• Subjects: Acanthocephala - classification; Acanthocephala - genetics; Animals; Biological and medical sciences; Biological taxonomies; Datasets; DNA, Helminth - chemistry; DNA, Ribosomal - chemistry; Echinorhynchida; Fundamental and applied biological sciences. Psychology; Gene sequencing; Genera; General aspects; General aspects and techniques. Study of several systematic groups. Models; Hypotheses; Invertebrates; Less representative or incertae sedis groups: acanthocephala, chaetognatha, gnathostomulida, lophophoria, merostomata, mesozoa, myxozoa, nematorhyncha, pararthropoda, placozoa, priapuloidea, prochordata, pycnogonida, rotifera; Likelihood Functions; Monophyly; Morphology; Nucleotide sequence; Palaeacanthocephala; Parasitology; Parsimony; Phylogenetics; Phylogeny; Plasmids; Polymerase chain reaction; Polymorphida; Probability; Ribosomal DNA; RNA, Ribosomal, 18S - genetics; RNA, Ribosomal, 28S - genetics; Rotifera - classification; Rotifera - genetics; Species; SYSTEMATICS-PHYLOGENETICS; Taxonomy; Vertebrates; United States > US; Ohio; California; Acanthocephala; Gene; Taxonomy; Ribosomal DNA; Parasite; Phylogeny; Invertebrata
• ISSN: 0022-3395; 1937-2345
• DOI: 10.1645/GE-523R.1

The Palaeacanthocephala is traditionally represented by 2 orders, Echinorhynchida and Polymorphida, with 10 and 3 families, respectively. To test the monophyly of the class, these 2 orders, and certain families, phylogenies were inferred using nuclear small-subunit (SSU) and large-subunit (LSU) ribosomal DNA sequences obtained for 29 species representing 10 families, 2 other classes of acanthocephalans, and 3 rotifer outgroups. Phylogenetic relationships were inferred by analyzing combined SSU and LSU sequences using maximum parsimony (MP) and maximum likelihood (ML) methods. Parsimony and ML trees inferred from combined analysis of these rDNA data strongly supported monophyly of Palaeacanthocephala and provided good resolution among species. Neither Polymorphida nor Echinorhynchida was monophyletic. Gorgorhynchoides bullocki (Echinorhynchida) was nested within the 6 species representing Polymorphida, and this clade was nested within species representing Echinorhynchida. Three of 4 palaeacanthocephalan families that could be evaluated were not monophyletic, and this finding was strongly supported. These results indicate that the family level classification of palaeacanthocephalans, which is mainly based on combinations of shared characters (not shared derived characters), needs to be reevaluated with respect to comprehensively sampled phylogenetic hypotheses.