Thoanteus
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| Wilhelm Lindholm , 1925 |
Thoanteus is a genus of the family of wolverines (Enidae) from the suborder of land snails ( Stylommatophora ).
features
The mostly left-handed, rarely right-handed, oblong-egg-shaped to oblong-conical cases are 12 to 22 mm high and 6 to 10 mm wide. They have seven to eight turns with a slightly curved periphery. The mouth is distorted U-shaped to pointed ovoid. The mouth edges are more or less strongly bent. The starting points of the mouth approach the previous turn. They are connected to one another by a more or less thick whitish layer. The mouth is toothless. The whitish-yellowish to horn-colored housings are rarely two-colored, i. H. show indistinct darker radial stripes. The surface is covered with fine strips of growth and fine spiral elements.
In the male tract of the genital apparatus, the few twisted vas deferens enter the comparatively short epiphallus . At the point of entry there is a short, conical flagellum, opposite the shorter, conical epiphallus caecum. The penis and epiphallus are roughly the same length. At the epiphallus / penis transition, the penis is greatly thickened, about three times the thickness of the epiphallus. The thickness gradually decreases to about half at the confluence of the penis with the atrium. A penile caecum is missing, the penile appendix opens directly into the atrium. It consists of a thickened lower part (A-1, slightly longer than the penis), from which A-3 to A-5 branches off in the lower half. In the type, this is fused with the spherical part (A-2). The thinner part (A-3) has the usual length, while the thin upper part (A-4) and the club-shaped end part are comparatively very short. In the other types, the penile appendix has the usual shape (thick lower part (A-1), spherical lower part (A-2), thinner middle part (A-3), very thin upper part (A-4) and club-shaped end part (A-5)). The stimulator inside the penis is cone-shaped with a longitudinal groove. The retractor muscle, which is divided into two strands, attaches to the penis, at the transition to the epiphallus and at the apical end of the thickened part (A-1 / A-2) of the penile appendix. In the female tract, the free fallopian tube (oviduct) is significantly longer than the vagina. The spermathec is moderately long, the stem thick and not twisted. The bladder comes to rest roughly near the prostate. A long worm-shaped diverticulum branches off just before the bladder .
Similar genera
The Thoanteus species are almost always left-handed, but there are also other genera of wolverine snails with species that have a left-handed shell. The difference lies in the anatomy of the genital tract. This is similar to the genus Zebrina , but here the penile appendix is still on the penis, but close to the atrium, and is much longer than in Thoanteus . The attachment points of the two retractor strands are the same in Thoanteus and Zebrina , but in Thonteus terminal on the penis and A-1 of the penile appendix, in Zebrina subterminal, clearly separated from the apical ends of the penis and A-1 of the penile appendix.
Geographical distribution
The genus occurs in the Crimea and in a small area in northern Turkey .
Taxonomy
The taxon was drawn up by Wilhelm Adolf Lindholm in 1925. Type species is Bulimus gibber Krynicki, established in 1833 by Lindholm. Today it is rated as a valid genus (Fauna Europaea, Gümüş & Neubert, Welter Schultes).
- Genus Thoanteus Lindholm, 1925
- Thoanteus corneus Hausdorf, 1993
- Thoanteus ferrarii house village, 1994
- Thoanteus gibber (Krynicki, 1833)
- Thoanteus zilchi Hausdorf, 1993
supporting documents
literature
- Burçin Aşkım Gümüş, Eike Neubert: New taxa of terrestrial molluscs from Turkey (Gastropoda, Pristilomatidae, Enidae, Hygromiidae, Helicidae). ZooKeys, 171: 17-37, 2012 doi : 10.3897 / zookeys.171.2273
- Nina V. Gural-Sverlova: Anatomical variability of Thoanteus gibber (Gastropoda, Pulmonata, Enidae) and its possible taxonomic importance. Zoologocheskij Zhurnal, 91 (5): 524-528 PDF
- Bernhard Hausdorf: The genus Thoanteus Lindholm in Asia Minor (Gastropoda: Buliminidae). Archives for Molluscology, 122 (1-6): 89-97, 1993.
- Bernhard Hausdorf: Additive typogenesis in Thoanteus (Gastropoda: Bulminidae). Zoological Journal of the Linnean Society, 112 (3): 353-361, 1994 doi : 10.1111 / j.1096-3642.1994.tb00325.x
- Anatolij A. Schileyko: Treatise on Recent Terrestrial Pulmonate Molluscs. Part 2. Gastrocoptidae, Hypselostomatidae, Vertiginidae, Truncatellinidae, Pachnodidae, Enidae, Sagdidae. Ruthenica, Supplement 2 (2): 129-261, Moscow 1998 ISSN 0136-0027
- Francisco W. Welter-Schultes: European non-marine molluscs, a guide for species identification = identification book for European land and freshwater mollusks. A1-A3 p., 679 p., Q1-Q78 p., Planet Poster Ed., Göttingen 2012, ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5 (p. 132)
Individual evidence
- ^ Wilhelm Adolf Lindholm (also Wassili Adolfowitsch Lindholm): Contribution to the systematics and nomenclature of the Enidae family (Buliminidae). Archives for Molluscology, 57: 23-41, Frankfurt / Main 1925.
- ↑ Fauna Europaea
