DNA barcodes and phylogenetic affinities of the terrestrial slugs Arion gilvus and A. ponsi (Gastropoda, Pulmonata, Arionidae).
The Iberian Peninsula is a region with a high endemicity of species of the terrestrial slug subgenus Mesarion. Many of these species have been described mainly on subtle differences in their proximal genitalia. It therefore remains to be investigated 1) whether these locally diverged taxa also represent different species under a phylogenetic species concept as has been shown for other Mesarion species outside the Iberian Peninsula, and 2) how these taxa are phylogenetically related. Here, we analysed DNA sequence data of two mitochondrial (COI and 16S) genes, and of the nuclear ITS1 region, to explore the phylogenetic affinities of two of these endemic taxa, viz. Arion gilvus Torres Mínguez, 1925 and A. ponsi Quintana Cardona, 2007. We also evaluated the use of these DNA sequence data as DNA barcodes for both species. Our results showed that ITS did not allow to differentiate among most of the Mesarion molecular operational taxonomic units (MOTUs) / morphospecies in Mesarion. Yet, the overall mean p-distance among the Mesarion MOTUs / morphospecies for both mtDNA fragments (16.7% for COI, 13% for 16S) was comparable to that between A. ponsi and its closest relative A. molinae (COI: 14.2%; 16S: 16.2%) and to that between A. gilvus and its closest relative A. urbiae (COI: 14.4%; 16S: 13.4%). Hence, with respect to mtDNA divergence, both A. ponsi and A. gilvus, behave as other Mesarion species or putative species-level MOTUs and thus are confirmed as distinct 'species'.
Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny (JEMU), Vautierstraat 29, B-1000 Brussels, Belgium.
Karin
K
Breugelmans
Royal Museum for Central Africa (JEMU), Leuvensesteenweg 13, B-3080 Tervuren, Belgium ; Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
Kurt
K
Jordaens
Laboratory of Pharmaceutical Technology, University of Ghent, Harelbekestraat 72, B-9000 Ghent, Belgium.
Els
E
Adriaens
Laboratory of Pharmaceutical Technology, University of Ghent, Harelbekestraat 72, B-9000 Ghent, Belgium.
Jean Paul
JP
Remon
Institut Catala de Paleontologia Miquel Crusafont, Universitat Autònomo de Barcelona, edifici ICP Campus de la UAB, sln 08193 Cerdanyola del Vallès, Barcelona, Spain.
Josep Quintana
JQ
Cardona
Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny (JEMU), Vautierstraat 29, B-1000 Brussels, Belgium ; Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
Thierry
T
Backeljau
Arion gilvus; Arion ponsi; DNA barcoding; Gastropoda; Iberian Peninsula; taxonomy; terrestrial slugs