title: Untangling the Ecology, Taxonomy, and Evolution of Chaetogaster limnaei (Oligochaeta: Naididae) Species Complex.
abstract: Within Oligochaeta, Chaetogaster limnaei is unusual in exhibiting a parasitic relationship with freshwater pulmonate snails. Taxonomic confusion has been caused by differences in what have been considered 2 subspecies of this worm: Chaetogaster limnaei limnaei is an ectosymbiont and is present inside the mantle cavity of the snail, whereas Chaetogaster limnaei vaghini is parasitic and lives in the kidney of the snail. This study explored the distribution of these annelids in central New York and used mitochondrial DNA sequence data from the COI locus to examine the relationship, evolution, and species status of the ectosymbiotic and parasitic forms of C. limnaei. Snails ( Physa gyrina ) were collected from 6 streams and lakes in central New York, with additional specimens collected from a lake in Massachusetts for comparison. One hundred and forty snails were examined, and at least 1 form of Chaetogaster was present in 88 specimens, a prevalence of 62.9%. COI sequence data from New York and Massachusetts did not reveal separate ectosymbiotic and parasitic lineages. Instead, all parasitic forms were part of a mixed clade that included both ectosymbiotic and parasitic forms. This mixed clade was nested within clades of ectosymbiotic forms only, suggesting that a plastic lineage of C. limnaei, able to be both ectosymbionts and parasites, evolved from ectoparasitic ancestors.
authors: Department of Biology, Virginia Military Institute, 301B Maury-Brooke Hall, Lexington, Virginia 24450.
authors: Ashleigh B
authors: AB
authors: Smythe
authors: Department of Biology, Virginia Military Institute, 301B Maury-Brooke Hall, Lexington, Virginia 24450.
authors: Kristin
authors: K
authors: Forgrave
authors: Department of Biology, Virginia Military Institute, 301B Maury-Brooke Hall, Lexington, Virginia 24450.
authors: Amanda
authors: A
authors: Patti
authors: Department of Biology, Virginia Military Institute, 301B Maury-Brooke Hall, Lexington, Virginia 24450.
authors: Rick
authors: R
authors: Hochberg
authors: Department of Biology, Virginia Military Institute, 301B Maury-Brooke Hall, Lexington, Virginia 24450.
authors: Marian K
authors: MK
authors: Litvaitis
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000302:isolation & purification; D004463:Ecology; D017753:Ecosystem; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D006239:Haplotypes; D060106:Lakes; D008404:Massachusetts; D008969:Molecular Sequence Data; D009518:New York; D009835:Oligochaeta / Q000145:classification* / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D061005:Ponds; D045483:Rivers; D016415:Sequence Alignment; D012908:Snails / Q000469:parasitology*; D013559:Symbiosis
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV