Molecular phylogeny of the genus Helix (Pulmonata: Helicidae)

Abstract

The vast diversity of land snail forms is insufficiently understood even in seemingly familiar taxa. This holds for Helix Linnaeus, 1758, a genus with several common edible species which comprises the largest Western Palearctic snails. The taxonomy of this genus, which has a centre of diversity in the eastern Mediterranean, has recently undergone significant changes, in both the delimitation of the genus itself and its species‐level systematics. Here, we compare the lineage diversity of Helix, as revealed by two mitochondrial markers, with the conclusions of the recently published morphology‐based taxonomic revision. For the molecular analysis, we assembled a representative data set covering almost all species of the genus as recognized by the mentioned revision. We obtained sequences not only from fresh and preserved soft tissues but also from dried tissue remains (some of them decades old) from shell collections. Our results show that the genus Helix, in the narrow sense proposed by recent studies, is paraphyletic because the genus Tacheopsis was unambiguously revealed as one of the tip branches of Helix. The monophyly of several species, as presently recognized, was not supported; partly, this may be attributed to a lineage diversity overlooked so far. This holds also for the type species of the genus, H. pomatia, which comprises at least one additional lineage. Greece, the Aegean and western Turkey is the core area for the diversity of Helix and its relatives, and the region is probably a major long‐term refuge for large Helicidae. The highest species diversity is found along the Alpide belt from the western Balkans to southern Turkey. The diversity of Helix in Europe, north of Greece and the Apennines, is a result of a single European radiation. Our data also suggest that past human activities likely influenced the present‐day distributions of some species.

History of two critically endangered grassland snails (Pulmonata: Helicellinae) in the Czech Republic with first molecular data on extinct populations

“…From the dried samples a ca 480 bp (all lengths including primers) fragment of the mitochondrial gene for 16S rRNA has been amplified and sequenced in three overlapping fragments of ca. 230-260 bp using methods and primers developed previously for the genus Helix L., 1758 (Korábek et al 2015). We have also tried to amplify the whole 480 bp fragment (as in Korábek et al 2015), but these attempts have been unsuccessful.…”

Contribution to the malacofauna of the north coast of Egypt

“…X. tuberculosa was also recorded from a wide area extending from Sinai, Egypt, to the coastal plains of Iran (biggs 1937) and from Umm el Jimâl, Jordan (neubeRt et al 2015). The species' range extends from Palestine, steppe and fruit land of Cyrenaica near the coast in north Libya to the Atlantic coast of Morocco.…”

“…It was observed to feed mainly on Egyptian clover, kidney bean and tomato in Kasfaryt and the Fayed district in Ismailia governorate (neubeRt et al 2015). mienis (2008) and PRévot et al (2015).…”

“…The shell morphology provides important diagnostic characters, especially that type specimens of most of the species recorded in this study are only shells (KoRábeK et al 2015). Besides identification, the specimens were subject to morphometric examination since much morphometric variation could be expected.…”

Development of the first polymorphic microsatellite markers for the Roman snail Helix pomatia L., 1758 (Helicidae) and cross-species amplification within the genus Helix

“…Due to this high interest from a gastronomical point of view, the species has been extensively analyzed in terms of both its biology and ecology, which are important for successful rearing and reproduction of individuals in snail farms. Genetic studies, however, are relatively new and do not focus exclusively on the analysis of this species, but rather on related species in the genus Helix (e.g., Mumladze et al, 2013;Korábek et al, 2014) or on the entire Helicidae family (e.g., Korábek et al, 2015). No microsatellite markers have been described to date for H. pomatia, as the previously mentioned studies used other types of molecular markers.…”