Exploring Monacha species from the island of Corfu (NW Greece) by an integrative approach: new insights on M. claustralis (Rossmässler, 1834), M. parumcincta (Rossmässler, 1834) and allied species (Gastropoda, Eupulmonata, Hygromiidae)

The Greek island of Corfu (Kérkyra) is considered the type locality of two <i>Monacha</i> species described in 1834 by Rossmässler, namely <i>Monacha claustralis</i> and <i>M. parumcincta</i>. In this work, Corfu populations of these species were investigated by an integrative approach including analysis of morphological features of shell and distal genitalia as well as molecular features of selected mitochondrial and nuclear gene fragments to establish the relationships between Corfu <i>M. claustralis</i> and <i>M. cartusiana</i> as well as between Corfu and Italian <i>M. parumcincta</i>. Shell features did not differentiate the pairs analysed, i.e. <i>Monacha claustralis</i> vs <i>M. cartusiana</i> and Corfu vs Italian <i>M. parumcincta</i>, whereas features of distal genitalia structure and nucleotide sequences of mitochondrial genes (COI and 16SrDNA) distinguished them significantly. Nuclear gene sequences (ITS2 flanked with 5.8S and 28SrDNA fragments) also differentiated between Corfu and Italian <i>M. parumcincta</i>. It is therefore postulated that these two pairs are composed of four separate species: <i>M. claustralis</i>, <i>M. cartusiana</i>, Corfu <i>M. parumcincta</i>, and Italian <i>M. parumcincta</i>, which are distinct from each other and from the other species of the genus <i>Monacha</i> used here for comparison (the six lineages of <i>M. cantiana</i> s.l. and <i>M. pantanellii</i>).