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Checklist of the Land Snails and Slugs of California. Second Edition

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... Because Vertigo demonstrate a high degree of aphallism and reduction in the male genitalia (Pokryszko, 1987 ), both species-level and supraspecific taxonomy has historically relied entirely upon shell characters such as overall shape, surface sculpture, aperture shape and lamellar configuration. Two subgenera, Vertigo (Angustula) and Vertigo (Vertillaria), constituting a total of perhaps only two species, have been given official taxonomic status (Pilsbry, 1948), while the genus Nearctula has been recently resurrected (Roth and Sadeghian, 2006) to encompass the Vertigo californica group of Pilsbry (1948). The remaining Vertigo have been traditionally assigned to a number of informal taxonomic groups that Pilsbry (1948) found quite ''difficult to formulate " . ...
... Vertigo modesta, V. ventricosa, V. hinkleyi and V. californica (a.k.a. Nearctula rowelli of Roth and Sadeghian, 2006) were included as putative congeneric outgroups whereas Gastrocopta tappaniana, Vallonia gracilicosta, Pupilla muscorum and P. hebes were included as extra-generic outgroups within the Pupillidae. ...
... These trees indicate that the genus Vertigo represents a monophyletic clade. Even though sometimes considered a member of a different genus (Nearctula of Roth and Sadeghian, 2006), Vertigo californica/Nearctula rowelli is in fact more similar in CO1 to other Vertigo species (64–88 bp differences) than it is to Vallonia, Gastrocopta or Pupilla (91–137 bp differences;Table 3). While Pupilla itself appears monophyletic, specimens of P. muscorum occur in two branches with the Minnesota individual actually being more similar to P. hebes. ...
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A phylogenetic analysis of 19 sibling taxa in the Vertigo gouldii group was conducted on 73 individuals sampled across North America using DNA sequence data of the mitochondrial genes cytochrome oxidase subunit 1 (CO1) and 16S ribosomal RNA (16S), and the internal transcribed spacer-2 of the nuclear ribosomal RNA (ITS-2) gene. The results of these analyses were found incongruent with previous taxonomic concepts used to define the V. gouldii group and its composite taxa that were based entirely on conchological features. The mtDNA sequence data suggest that some previous members of the traditional V. gouldii group may be more closely related to V. modesta. They also suggest that V. gouldii may itself consist of seven species-level branches spread across two deeply rooted clades. Revision of geographical distributions on the basis of these analyses suggests that these Vertigo species may commonly possess continental-sized ranges in spite of their minute size and limited active dispersal ability. High levels of sympatry within the group are also confirmed, with up to four species being known to co-occur within single microsites. These data also suggest that rates of diversification have been non-constant. Assuming a 1%/my rate of base pair substitution, a 10-fold diversification pulse is indicated from 6.7–7.0 myBP, which would be co-incident with known mid-late Miocene global climate changes.
... Eobania vermiculata is a well-known circum- Mediterranean species (Neubert, 1998). This species is well known for its survival capability and has been introduced by human activity to many countries ranging from USA (Roth and Sadeghian, 2006) to Japan (Ueshima et al., 2004). It was recorded for the first time in central Saudi Arabia by Mordan (1980). ...
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Eobania vermiculata is a well-known circum-Mediterranean land snail having a cosmopolitan distribution that makes it suitable for phylogenetic studies. The present work examines the phylogenetic relationships of two populations of this land snail from Egypt and Saudi Arabia using mitochondrial markers (partial 16S rDNA and COI gene sequencing) in addition to traditional methods of shell’s shape analysis. The study highlights the extraordinary morphological variations between the two studied snail populations. This variation seems to be related to the geographic origin but not the colouration of the shell and may have caused the present changes in their mitochondrial genes. The molecular phylogenetic analysis of partial 16S rDNA and COI gene segments confirms the morphological findings. The two monophyletic populations of Egyptian and Saudi Arabian E. vermiculata were found to represent two distinct groups. The concordance of morphological and molecular results, that produced very clear separation of both populations, leads us to conclude that the two separate groups could be considered two separate subspecies.
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Phorid flies are amongst the most biologically diverse and species-rich groups of insects. Ways of life range from parasitism, herbivory, fungivory, to scavenging. Although the lifestyles of most species are unknown, many are parasitoids, especially of social insects. Some species of ant-parasitoids are attracted to injured hosts for feeding purposes to develop eggs, as well as for oviposition, requiring each female to find two injured hosts. Females of the phorid fly Megaselia steptoeae Hartop et al. (Diptera: Phoridae) were found to be quickly attracted to crushed glass snails of the species Oxychilus draparnaudi (Beck) (Gastropoda: Oxychilidae). Most females were without mature eggs and apparently were attracted for feeding purposes only; other injured molluscs offered at the same time were not attractive. One female laid eggs in captivity and offspring were reared to the pupal stage. The lifestyle of this species is similar to that of parasitoids of injured ants, which also require separate hosts of the same species for feeding and oviposition. We conclude that injured hosts must be common in the environment to attract these host-specific scavengers.
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This is the very first checklist of the terrestrial gastropods of Nepal. It includes 138 species and six subspecies, of which 22 species are endemic and four are introduced. It highlights 34 species recorded for the first time in Nepal and provides new distribution records for another 30 species.
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The complete sequences of three mitochondrial genomes from the land snail Cornu aspersum were determined. The mitogenome has a length of 14050 bp, and it encodes 13 protein-coding genes, 22 transfer RNA genes and two ribosomal RNA genes. It also includes nine small intergene spacers, and a large AT-rich intergenic spacer. The intra-specific divergence analysis revealed that COX1 has the lower genetic differentiation, while the most divergent genes were NADH1, NADH3 and NADH4. With the exception of Euhadra herklotsi, the structural comparisons showed the same gene order within the family Helicidae, and nearly identical gene organization to that found in order Pulmonata. Phylogenetic reconstruction recovered Basommatophora as polyphyletic group, whereas Eupulmonata and Pulmonata as paraphyletic groups. Bayesian and Maximum Likelihood analyses showed that C. aspersum is a close relative of Cepaea nemoralis, and with the other Helicidae species form a sister group of Albinaria caerulea, supporting the monophyly of the Stylommatophora clade. Citation: Gaitán-Espitia JD, Nespolo RF, Opazo JC (2013) The Complete Mitochondrial Genome of the Land Snail Cornu aspersum (Helicidae: Mollusca): Intra-Specific Divergence of Protein-Coding Genes and Phylogenetic Considerations within Euthyneura. PLoS ONE 8(6): e67299. doi:10.1371/journal.pone.0067299 Copyright: ß 2013 Gaitán-Espitia et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Recent land snail inventories in New York State have led to the discovery of new state geographic distribution records for seven species: Carychium nannodes Clapp, 1905; Gastrocopta procera (Gould, 1840); Lucilla scintilla (R.T. Lowe, 1852); Striatura meridionalis (Pilsbry and Ferriss, 1906); Trochulus hispida (Linnaeus, 1758); Vertigo cristata Sterki, 1919; and Vertigo paradoxa Sterki, 1900. Most are native species of eastern North America, although T. hispida is introduced from Europe. These species were found mainly by field searches in a variety of habitats — roadsides, fields, forested rock talus and limestone outcrops, and coastal freshwater wetlands - but in one case through verification of specimens at the New York State Museum.
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Identification of the two most widespread European Oxychilus species, O. cellarius (Müller, 1774) and O. draparnaudi (Beck, 1837) is still mainly based on conchological features of controversial diagnostic value. Despite this, certain anatomical characters, known since Taylor's (1905-21) excellent monograph, enable the two species to be readily distinguished. O. cellarius has a cylindrical penis, rather constant in width in the middle portion, whereas that of O. draparnaudi is divided by an abrupt constriction into a usually shorter slender proximal portion and a longer wider distal portion. The two portions communicate through a very slender "bottle-neck", level with constriction. Obviously, apart from other differences in the internal ornamentation of the penis (fewer larger papillae in single rows, papillae sometimes fused to form wavy pleats in O. cellarius), most of the rows of papillae of the proximal penis of O. cellarius are continuous with the pleats of the distal penis, whereas in O. draparnaudi the rows of papillae of the proximal penis stop at the "bottle-neck" and the pleats of the distal penis begin after it, without any continuity with the rows of papillae of the proximal penis.
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Globose-shelled to depressed-helicoid terrestrial snails of the subgenus Helminthoglypta (Charodotes) occur from the vicinity of Morro Bay to the City of San Luis Obispo in San Luis Obispo County, central California, USA. Populations with intensely papillose shells largely or entirely lacking incised spiral sculpture, originally described as "Helix var. morroensis," have been regarded as either a subspecies of Helminthoglypta walkeriana (Hemphill, 1911) or an infrasubspecific variation without taxonomic significance. Shell form variation is distributed as one would expect if the two major aggregations of individuals were reproductively isolated, biological species, H. walkeriana and H. morroensis (Hemphill, 1911). Differing penial morphology is also consistent with reproductive isolation. The two species appear to be allopatric.
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Roth, Barry (2003): Polygyrid land snails, Vespericola (Gastropoda: Pulmonata), 4. A new and possibly extinct species from central California, U. S. A. Zootaxa 215: 1-6, DOI: 10.5281/zenodo.156810