Zoogenetes harpa
| Zoogenetes harpa | ||||||||||||
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Zoogenetes harpa |
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| Morse , 1864 | ||||||||||||
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| Zoogenetes harpa | ||||||||||||
| ( Say , 1824) |
Zoogenetes harpa is a terrestrial snail species from the family of grass snails (Valloniidae); the family belongs to the subordination of land snails (Stylommatophora). It is (currently) the only species of the genus Zoogenetes Morse, 1864.
features
The cone-shaped case is 3 to 4 mm high (3.0 to 5.2 mm) and 2.4 to 3 mm wide (2.5 to 3.5 mm). It consists of 3.5 to 4 moderately arched turns, which are often slightly flattened on the side. The last turn does not leave the coil axis. The mouth is usually egg-shaped or elliptical and is slightly oblique to the longitudinal axis of the housing. The edge of the mouth is thin and fragile, the edge not turned over or expanded. The housing or shell is only slightly calcified, but elastic to a certain extent due to the periostracum . The surface of the embryonic housing shows very fine, somewhat irregular spiral stripes, while the teleoconch is covered with more or less regular, fine, lamellar ribs formed from the periostracum. Fine strips of growth can be observed between the ribs under the microscope. Thanks to the fine ribs, fresh casings appear iridescent. The cylindrical umbilicus is open. The housing is brownish, horn-colored-greenish to olive-colored.
The soft body is quite small in relation to the housing diameter. The foot is about two thirds of the length of the housing diameter. The soft body and the head are slate gray. The upper, comparatively short and thick tentacles are somewhat darker, the lower tentacles are very short. The eyes are relatively large. The radula has 37 elements per transverse row, so it has 18 posterior teeth in addition to the central tooth. The jaw is strongly curved and has numerous longitudinal pits on the surface that run across the curve.
So far, almost all specimens examined anatomically have been aphallic, i. H. the male ducts in the hermaphroditic genitalia are regressed. In some specimens, the sperm duct branches off from the egg duct (sperm duct), but then ends blindly. Euphallic specimens (with penis and epiphallus) are still rare. The spermatic duct is comparatively shortly before it merges into the epiphallus. This is elongated spindle-shaped. A long appendix starts at the epiphallus / penis transition. The retractor muscle attaches to the epiphallus and appendix. The free fallopian tube and vagina are roughly the same length. The stem of the spermathek is short and thin, the bladder small, elongated, club-shaped and practically not set off against the stem.
Similar species
The genus (and species) is similar to the genus Acanthinula (and their species). The ribs are weaker and less regular compared to this genus.
Geographical distribution and habitat
The species or genus is distributed holartically . However, it is limited to the polar regions and the higher mountains ( Rocky Mountains , Alps , Caucasus ). In Switzerland it occurs up to 2200 m above sea level.
It lives in coniferous forests, often on non-calcareous, even acidic soils (in Switzerland on soils with pH values of 3.5 to 5.5), which is overgrown with species of the genus blueberries ( Vaccinium ).
Way of life
In most of the animals, the male walkways have regressed and the animals reproduce almost exclusively through self-fertilization. Accordingly, copulations are very rare. The species is ovoviviparous , i.e. H. two to four eggs are retained in the uterus, where they gradually develop, i.e. H. the eggs in the uterus are at different stages of development. The young hatch out of the egg shell in the parent animal and then leave the parent animal; they have already formed two housing turns. The animals often only hibernate a few centimeters under leaves or stones. The mouth is closed by an epiphragm . In this way they outlast dry periods in summer, often only attached to the underside of leaves. They will probably be one year old.
Taxonomy
The Arttaxon was introduced into scientific literature in 1824 by Thomas Say in a work by William Hypolitus Keating as Helix harpa . Edward S. Morse established the genus Zoogenetes for this species in 1864 . The genus has remained monotypical since then; H. contains only this one species. Henry Augustus Pilsbry added a second species, Helix harpula Reinhardt, to the genus Zoogenetes in 1886 with a question mark . This species has now been classified in the genus Pupisoma . It is possible that a second species belongs to the genus Zoogenetes . Zoogenetes tyosenica Kuroda & Hukuda, 1944 from the Korean peninsula has basically not been considered since it was first described.
Danger
The species is classified as not endangered in Switzerland.
supporting documents
literature
- Michael P. Kerney, Robert AD Cameron & Jürgen H. Jungbluth: The land snails of Northern and Central Europe. 384 pp., Paul Parey, Hamburg & Berlin 1983, ISBN 3-490-17918-8 (p. 133)
- Anatolij A. Schileyko: Treatise on Recent terrestrial pulmonate molluscs, Part 1. Achatinellidae, Amastridae, Orculidae, Strobilopsidae, Spelaeodiscidae, Valloniidae, Cochlicopidae, Pupillidae, Chondrinidae, Pyramidulidae. Ruthenica, Supplement 2 (1): 1-126, 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. 208)
Individual evidence
- ↑ a b Schileyko, Treatise, 1, p. 96.
- ^ A b c Henry Augustus Pilsbry: Land Mollusca of North America: (north of Mexico). Academy of Naturural Sciences of Philadelphia, Monographs 3: 1113 S., Philadelphia 1948 [books.google.de/books?id=EyHywT05a0QC&pg=PA1042 Online at Google Books] (pp. 1041-1045)
- ^ William Hypolitus Keating: Narrative of an expedition to the source of St. Peter's River, Lake Winnepeek, Lake of the woods, & c. & c. performed in the Year 1823, by order of the hon. JC Calhoun, under the Command of Stephen H. Long. Compiled from the notes of Major Long, Messrs. Say, Keating, and Colhoun. In two volumes. Vol. II. Pp. I-VI, 5-459, Carey & Lea, Philadelphia 1824. Online at www.biodiversitylibrary.org (p. 256).
- ^ Edward S. Morse: Observations on the terrestrial Pulmonifera, including a catalog of all species of terrestrial and fluviatile Mollusca known to inhabit the state. Journal of the Portland Society of Natural History, 1 (1): 1-63, Pl. I-II [= 1-2], 3-10, 1864 Online at www.biodiversitylibrary.org (pp. 5, 32-36 ).
- ↑ Fauna Europaea
- ^ Henry Augustus Pilsbry: Manual of Conchology. Second Series: Pulmonata. Vol. 27. Pupillidae (Orculinae, Pagodulinae, Acanthinulinae, etc). SI-IV, 1-369, Philadelphia 1922-1926. Online at www.biodiversitylibrary.org (p. 195/6)
- ↑ World Wide Mollusc Species Data Base by Bagni Liggi (the exact citation from Kuroda & Hukuda (1944) has not yet been determined).
- ^ Welter-Schultes, European non-marine molluscs, p. 208
