Cantareus aspersum, (Muller, 1774)

Blacket, Mark J., Shea, Michael, Semeraro, Linda & Malipatil, Mallik B., 2016, Introduced Helicidae Garden Snails in Australia: Morphological and Molecular Diagnostics, Species Distributions and Systematics, Records of the Australian Museum 68 (3), pp. 99-116 : 113

Cornu aspersum ( Müller, 1774)

Objective synonyms— Helix aspersa , Cantareus aspersa , Cryptomphalus aspersus.

Common names — Brown Garden Snail, Common Garden Snail.

Material examined. New South Wales: AM C121130 Jenolan Caves; AM C430603 St. Peters, Sydney; AM C430605 Seal Rocks headland south of Forster; AM C430607 Timor Caves camping ground, Upper Hunter River; AM C456977 east of Glen Davis at end of Capertee River track; AM C430602 Swansea, south of Newcastle. Victoria: Blackburn South VAITC 3037, VAIC ×1; Cobram VAITC 3072, 3073; Doncaster VAITC 3022, VAIC ×3; Knoxfield VAITC 3015, 3071, VAIC ×7; Irymple VAITC 3077, 3078, 3080, VAIC ×11; Preston VAITC 3076, VAIC ×4; Ringwood East VAITC 3047, 3048, VAIC ×5.

Diagnosis. Shell: large (up to 4 cm), thin, raised spire, globose, 4–5 whorls increasing rapidly with body-whorl greatly flared, aperture large and rounded, umbilicus closed, shell lip thickened white and strongly reflected out in adults, rounded whorls in both adults and juveniles. Shell colour: light brown with darker spiral bands and yellow flecks. During aestivation: possesses either thin and clear or thickened and greyish green epiphragm, that is not convex positioned inside the aperture. Soft body: greenish-grey with a pale dorsal stripe. Adults: identified by the presence of a thickened reflected lip, indicating maturity and the cessation of growth (sensu Madec et al., 2003).

Distribution in Australia. Present in parts of all Australian states and territories.

Remarks. The species identification of VAITC specimens (above) was confirmed in the present study through DNA barcoding (ITS2 & COI) and comparison with validated AM specimens. In this study we employed the generic name Cornu, as is currently accepted (ICZN Case 3518—ICZN, 2015). Phylogenetic estimates of relationships within Helicidae show that Green and Brown Garden snails are closely related based on both 16S ( Manganelli et al., 2005; Groenenberg et al., 2011; Razkin et al., 2015) and ITS2 ( Wade et al., 2006; Régnier et al., 2011; Razkin et al., 2015) DNA sequences, with most of these previous studies placing these two species in the same genus, Cantareus , as proposed by Guisti et al. (1996), on the basis of a shared morphological internal synapomorphy. However, the majority of recent studies place Brown Garden Snails in Cornu (as in the present study). Indeed, in the present study Brown and Green Garden Snails do appear to be substantially genetically distinct based on COI variation ( Table 5, Fig. 9 ), adding some support to the placement of these species in different genera. The placement of Brown Garden Snails in the genus Helix is not supported by molecular evidence, with species of Helix now placed in a different tribe from C. aspersum and C. apertus (e.g., Razkin et al., 2015). Cornu currently contains a single species (CABI species datasheet, http://www.cabi.org/isc/datasheet/26821).

Figures

Figure 9. Neighbour-joining tree of Helicidae (COI locus), including DNA sequences from many Helicidae genera present on GenBank.Sequences fromAustralian specimensfrom the present study are indicated as black filled circles. Theba pisana pisana lineages indicated by numbers in brackets, from Daumer et al. (2012), T. pisana (WA) = Genbank HM034599 five specimens collected from Western Australia, from Daumer et al. (2012). Country of origin for Genbank Cornu specimens in brackets.