title: Exploring species level taxonomy and species delimitation methods in the facultatively self-fertilizing land snail genus Rumina (gastropoda: pulmonata).
abstract: Delimiting species in facultatively selfing taxa is a challenging problem of which the terrestrial pulmonate snail genus Rumina is a good example. These snails have a mixed breeding system and show a high degree of shell and color variation. Three nominal species (R. decollata, R. saharica and R. paivae) and two color morphs within R. decollata (dark and light) are currently recognized. The present study aims at evaluating to what extent these entities reflect evolutionary diverging taxonomic units, rather than fixed polymorphisms due to sustained selfing. Therefore, a phylogenetic analysis of nuclear (ITS1, ITS2) and mitochondrial DNA (COI, CytB, 12S rDNA, 16S rDNA) sequences was performed. Putative species in Rumina, inferred from the mitochondrial DNA phylogeny, were compared with those proposed on the basis of the COI gene by (1) DNA barcoding gap analysis, (2) Automatic Barcode Gap Discovery, (3) the species delimitation plug-in of the Geneious software, (4) the Genealogical Sorting Index, and (5) the General Mixed Yule Coalescent model. It is shown that these methods produce a variety of different species hypotheses and as such one may wonder to what extent species delimitation methods are really useful. With respect to Rumina, the data suggest at least seven species, one corresponding to R. saharica and six that are currently grouped under the name R. decollata. The species-level status of R. paivae is rejected.
authors.affiliation: Royal Belgian Institute of Natural Sciences, Brussels, Belgium ; Laboratoire d'Evolution Biologique et Ecologie, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Vanya
authors.initials: V
authors.lastname: Prévot
authors.forename: Kurt
authors.initials: K
authors.lastname: Jordaens
authors.forename: Gontran
authors.initials: G
authors.lastname: Sonet
authors.forename: Thierry
authors.initials: T
authors.lastname: Backeljau
mesh_terms: D000818:Animals; D002965:Classification / Q000379:methods*; D058893:DNA Barcoding, Taxonomic; D004272:DNA, Mitochondrial / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005306:Fertilization; D005819:Genetic Markers / Q000235:genetics; D015233:Models, Statistical; D010802:Phylogeny; D012908:Snails / Q000145:classification* / Q000235:genetics / Q000502:physiology*
chemical_list: D004272:DNA, Mitochondrial; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers