Walklea rossmaessleri
| Walklea rossmaessleri | ||||||||||||
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Walklea rossmaessleri |
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| Scientific name of the genus | ||||||||||||
| Walklea | ||||||||||||
| Gittenberger , 1978 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Walklea rossmaessleri | ||||||||||||
| ( Roßäßler , 1838) |
Walklea rossmaessleri , also uncommonly Geripptes Zahnkreistönnchen , is a type of snail from the family of the barrel snail (Orculidae), which belongs to the subordination of the land snail (Stylommatophora). It is the only species in the genus Walklea Gittenberger, 1978. The genus name honors the mollusc researcher Walter Klemm .
features
The right-hand wound housing is conical or slightly ovoid with seven (5 to 5.5 turns, probably mistakenly!) Moderately curved turns that increase rapidly and are separated from each other by a deep seam. The last turn increases slightly and gradually from the turn axis. The cases are 4.5 to 4.7 mm high and 3.7 to 3.8 mm (5 to 6 × 4 to 4.5 mm) in diameter. The skin is moderately thick, translucent and uniformly horn-colored, the surface shiny. Often, however, the housing is covered with clay and excrement to camouflage it. The embryonic convolutions are almost smooth, the following convolutions regularly ribbed. The rounded mouth is almost perpendicular to the coil axis. The edges are only slightly, but sharply bent back. A weak whitish lip is formed inside. Due to the strong development of the parietal callus, the mouth is almost free. The mouth is reinforced with 9 to 10 teeth. The juvenile stages have not yet formed any teeth in the mouth. The navel is closed.
The soft body is light blue-gray, the long upper eye bearers are darker gray. In the female genital tract, the free fallopian tubes and vagina are roughly the same length. The stalk is thick and long (without diverticulum ), the spermathec is comparatively small and hardly thicker than the stalk. The spermatic duct is comparatively long and not very twisted. It penetrates apically into the comparatively short and thick epiphallus. The penis is longer than the epiphallus. A short, conical flagellum attaches to the transition to the penis. The penis is divided into a proximal and a distal half by the disproportionately long and thick penile appendix, which attaches roughly in the middle of the penis. The penile retractor divides and starts in the distal half just before the flagellum and almost at the base of the penile appendix. The radula half-transverse row has the formula Z + 22, i.e. one central tooth and 22 secondary teeth each following laterally.
Similar species
The shell of Walklea rossmaessleri is similar to that of Odontocyclas kokeilii , but is significantly larger and the outline is slightly curved outwards. The latter species also has an open umbilicus and a smaller, not so prominent final turn. In addition, the clear radial sculpture is missing.
Both types differ, however, clearly in the sexual apparatus. In Walklea rossmaessleri the penile appendix is conspicuous and much longer. In addition, a flagellum is formed, which is missing in Odontocyclas kokeilii . On the other hand, the epiphallus of this type is significantly longer in relation to the penis. In Walklea rossmaessleri a diverticulum on the stem of the spermathecae missing.
Geographical distribution and habitat
The distribution area of the species extends from northeast Italy to western Slovenia. The animals live under stones and in the leaf litter.
Taxonomy
The species was first described in 1838 by Emil Adolf Rossmässler under the binomial Pupa Rossmaessleri . The fact that Rossmässler received the material from his friend Ferdinand Jožef Schmidt (Šmit) , who apparently named the species on the label (or verbally) rossmaessleri , resulted in the fact that the species was named after itself, which is very unusual . In the publication and description of the species, however, no contribution from Schmidt is evident; the species must therefore be attributed to Rossmässler. It was initially placed in the genus Odontocyclas . Edmund Gittenberger examined the genital apparatus and found great differences to the type of Odontocyclas . He therefore proposed the new genus Walklea , a word created in honor of the mollusc researcher Wal ter Kle mm.
Danger
The species is restricted to a small area in the border area between Italy and Slovenia, but is known from some localities there. These are not endangered by human intervention. There is also no evidence that populations are declining. The International Union for Conservation of Nature and Natural Resources (IUCN) therefore classified it as not endangered.
supporting documents
literature
- Rosina Fechter, Gerhard Falkner: Mollusks. 287 p., Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10) ISBN 3-570-03414-3 (p. 146)
- Edmund Gittenberger: Contributions to the knowledge of the Pupillacea VIII. Some about Orculidae. Zoologische Verhandelingen, 163: 3-44, 1978 PDF
- Bernhard Hausdorf: The Orculidae of Asia (Gastropoda: Stylommatophora). Archives for Molluscology, 125 (1/2): 1–86, Frankfurt / M. 1996.
- 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 (hereinafter Schileyko, Treatise with page number)
On-line
Individual evidence
- ↑ Schileyko, Treatise, p. 62
- ↑ Francisco W. Welter-Schultes: European non-marine molluscs, a guide for species identification = identification book for European land and freshwater mollusks. A1-A3 S., 679 S., Q1-Q78 S., Göttingen, Planet Poster Ed., 2012 ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5
- ^ Emil Adolf Rossmässler: Iconography of the land and freshwater molluscs, with special consideration of the European species not yet shown. Second volume. Issue 7/8: 1-44, Issue 9/10: 1–66, Issue 11: 1–15, Issue 12: 1–37, Plates 31–60, Dresden, Leipzig, Arnoldische Buchhandlung, 1838–1844. Online at www.biodiversitylibrary.org (original / short description: Issue 7–8, p. 39, footnote), online at www.biodiversitylibrary.org (detailed description: Issue 9–10, p. 27), online at www. biodiversitylibrary.org (Figure: Plate 49 Fig. 644)
- ↑ Austrian Biographical Lexicon 1815 - 1950: Ferdinand Jožef Schmidt (Šmit)
- ↑ Walklea rossmaessleri in the Red List of Threatened Species of the IUCN 2013.2. Posted by: Feher, Z. & Slapnik, R., 2011. Retrieved March 18, 2014.