Redescription of Monacha pantanellii (De Stefani, 1879), a species endemic to the central Apennines, Italy (Gastropoda, Eupulmonata, Hygromiidae) by an integrative molecular and morphological approach

Abstract

Specimens obtained from ten populations of a Monacha species from the central Apennines were compared with six molecular lineages of Monacha cantiana s. l. (CAN-1, CAN-2, CAN-3, CAN-4, CAN-5, CAN-6) and two other Monacha species (M. cartusiana and M. parumcincta), treated as outgroup, by molecular (nucleotide sequences of two mitochondrial COI and 16S rDNA as well as two nuclear ITS2 and H3 gene fragments) and morphological (shell and genital anatomy) analysis. The results strongly suggest that these populations represent a separate species for which two names are available: the older Helix pantanellii De Stefani, 1879 and the junior M. ruffoi Giusti, 1973. The nucleotide sequences created well separated clades on each phylogenetic tree. Genital anatomy included several distinctive features concerning vaginal appendix, penis, penial papilla and flagellum; instead, shell characters only enabled them to be distinguished from M. cartusiana and M. parumcincta. Remarkably, populations of M. pantanellii show high morphological variability. Shell variability mainly concerns size, some populations having very small dimensions. Genital variability shows a more intricate pattern of all anatomical parts, being higher as regards the vagina and vaginal appendix. Despite this morphological variability, the K2P distance range of COI sequences between populations is narrow (0.2–4.5%), if we consider all but three of the 53 sequences obtained. This research confirmed that the species of Monacha and their molecularly distinguished lineages can only occasionally be recognised morphologically and that they have significant inter- and intra-population variability. The possibility of using an overall approach, including shell, genital and molecular evidence, was taken in order to establish a reliable taxonomic setting.

Next step in Monacha cantiana (Montagu, 1803) phylogeography: northern French and Dutch populations (Eupulmonata, Stylommatophora, Hygromiidae)

“…8 . The results are consistent with previously published findings ( Pieńkowska et al 2018b , 2019a , 2019b , 2020 , 2022 ), distinguishing six lineages (CAN-1 – CAN-6) in M. cantiana s.l. that clustered separately from COI sequences of other species including M. parumcincta , M. pantanellii and M. cartusiana .…”

“…In this sense, the molecular results complement the conclusions of Brulé and Bichain (2019) . Consequently, their results corroborate the results of four previous papers on M. cantiana lineages and their phylogeography ( Pieńkowska et al 2018b , 2019a , 2019b , 2020 ).…”

“…Sequences deposited in GenBank for M. cantiana s.l. from other populations ( Manganelli et al 2005 ; Duda et al 2011 ; Kruckenhauser et al 2014 ; Cadahia et al 2014 ; Pieńkowska et al 2015 , 2018b , 2019a , 2019b ; Razkin et al 2015 ; Neiber and Hausdorf 2017 ; Čejka et al 2020 , 2022 ) and three other Monacha species ( M. cartusiana : Pieńkowska et al 2015 , 2022 ; Neiber and Hausdorf 2017 ; Caro et al 2019 ; Čejka et al 2020 ; M. pantanellii (De Stefani, 1879): Pieńkowska et al 2020 ; M. parumcincta (Rossmässler, 1834): Pieńkowska et al 2018b ) were also selected for molecular analysis (Suppl. materials 1 – 4 ) and supplemented with several new sequences of mitochondrial ( 16SrDNA ) and nuclear ( ITS2 flanked with 5.8SrDNA and 28SrDNA) genes (Table 1 ).…”

“…The material examined originated from the populations listed in Table 1 with the following data: geographic coordinates, country and region, short description of collection site, name of collector, date, number of specimens studied and the collection where the material is stored (in brackets). The origin of the material used for comparison has been described in previous publications ( Pieńkowska et al 2015 : appendix 1; Pieńkowska et al 2018b , 2019a , 2019b , 2020 , 2022 : table 1).…”