New insights into and limitations of the molecular phylogeny in the taxon‐rich land snail genusMontenegrina(Mollusca: Gastropoda: Clausiliidae)

Morphological investigation of genital organs and first insights into the phylogeny of the genus Siciliaria Vest, 1867 as a basis for a taxonomic revision (Mollusca, Gastropoda, Clausiliidae)

“…First, intra specific distances were found to vary considerably among various land snail species and are sometimes higher than commonly reported interspecific distances (Davison et al 2009). Further examples for high intraspecific distances are the clausiliid genera Montenegrina (Mason et al 2020a) and Clausilia (Mason et al 2020b), the genus Schileykula (Harl et al 2019) and the genetically highly diverse hairy snail Trochulus hispidus where even budding speciation was observed (Kruckenhauser et al 2011).…”

“…We systematically introduced new genital anatomical characters for the above listed genera. This study follows the strategy and methods of the recently published integrative approach to the taxonomy and systematics within Montenegrina Boettger, 1877(De Mattia et al 2020Mason et al 2020a), where DNA-based phylogenetic trees together with morphological characters (both shell and morphology of genital organs) were the basis for a taxonomic revision.…”

“…We deliberately refrained from applying automated species delimitation methods, for which larger sample sizes would have been necessary. Furthermore, in various land snail species as it was shown such methods may deliver discordant results (e.g., Prevot et al 2013;Modica et al 2016;Batomalaque et al 2019;Mason et al 2020a), there may be a lot of factors hampering straightforward delimitation solely based on genetic clades and the concept of the DNA barcoding gap (Meier et. al.…”

“…So far, mostly mitochondrial marker sequences were used successfully in phylogenetic studies of land snails. The quite frequently used nuclear encoded histone genes H3 and H4 (including the spacer region in-between) often did not add much informa-tion or even resulted in confusing trees, probably due to multiple paralogous copies of these genes that escaped homogenisation and/or recombination events after hybridisation (e.g., Harl et al 2019;Mason et al 2020a). Indication for interspecific hybridisation, even (at least sporadically) over wide phylogenetic distances were reported for several species, e.g., in the clausiliid genus Montenegrina (Mason et al 2020a).…”

“…The quite frequently used nuclear encoded histone genes H3 and H4 (including the spacer region in-between) often did not add much informa-tion or even resulted in confusing trees, probably due to multiple paralogous copies of these genes that escaped homogenisation and/or recombination events after hybridisation (e.g., Harl et al 2019;Mason et al 2020a). Indication for interspecific hybridisation, even (at least sporadically) over wide phylogenetic distances were reported for several species, e.g., in the clausiliid genus Montenegrina (Mason et al 2020a). Further examples were found e.g., in the bradybaenid land snail genera Ainohelix and Ezohelix (Morii et al 2015) or the orculid genus Schileykula (Harl et al 2019).…”