Integrative taxonomy discloses nematode hidden diversity
Fonseca, G.; Derycke, S.; Moens, T. (2007). Integrative taxonomy discloses nematode hidden diversity, in: Derycke, S. Patronen en processen in de genetische structuur van twee mariene nemarodentaxa Rhabditis (Pellioditis) marina and Halomonhystera disjuncta): een moleculaire, morfologische en experimentele benadering = Patterns and processes in the genetic structure of two marine nematode taxa (Rhabditis (Pellioditis) marina and Halomonhystera disjuncta): a molecular, morphology and experimental approach. pp. 89-111 In: Derycke, S. (2007). Patronen en processen in de genetische structuur van twee mariene nemarodentaxa Rhabditis (Pellioditis) marina and Halomonhystera disjuncta): een moleculaire, morfologische en experimentele benadering = Patterns and processes in the genetic structure of two marine nematode taxa (Rhabditis (Pellioditis) marina and Halomonhystera disjuncta): a molecular, morphology and experimental approach. PhD Thesis. Universiteit Gent. Faculteit Wetenschappen: Gent. X, 252 pp., more |
| Keywords | Classification > Taxonomy
Species diversity
Halomonhystera disjuncta (Bastian, 1865) Andrássy, 2006 [WoRMS]; Nematoda [WoRMS]; Rhabditis (Pellioditis) marina (Bastian, 1865) Dougherty, 1955 [WoRMS]
Marine/Coastal |
| Abstract | Integrative taxonomy considers species boundaries from multiple, complementary perspectives, the main objective being to compare the observed data against the predictions of the methodologies used. In the present study we used four methods for delineating species boundaries within the cosmopolitan nematode species Halomonhystera disjuncta and Rhabditis (Pellioditis) marina. First, phylogenetic relationships among molecular sequences from the mitochondrial cytochrome oxidase c subunit 1 gene (COI) and from the nuclear internal transcribed spacer region (ITS) were analysed. Subsequently, multivariate morphometric analysis was used to investigate whether concordant molecular lineages were also morphologically distinct. When morphological differences were found, typological taxonomy was performed in order to identify fixed or non-overlapping characters between lineages. Finally, interbreeding experiments were conducted between the two closest related lineages to investigate potential reproductive isolation. This integrative approach confirmed the presence of several species within each nominative species: molecular lineages were concordant across two independent loci, and were characterized by significant morphological divergence. The two lineages investigated in our study did not produce offspring. Our results highlight that classical taxonomy grossly underestimates species diversity within the phylum Nematoda. |
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