Lauria (genus)

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Lauria
Nabeled pupa snail (Lauria cylindracea)

Nabeled pupa snail ( Lauria cylindracea )

Systematics
Superordinate : Heterobranchia
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Pupilloidea
Family : Lauriidae
Genre : Lauria
Scientific name
Lauria
Gray , 1840

Lauria is a living on the land snails - genus of the family lauriidae that the terrestrial snails is provided (gastropod).

features

The housings are egg-shaped, elongated-egg-shaped to approximately cylindrical with five to seven turns, which are moderately curved at the periphery. They are 2.3 to 4.5 mm high and 1.5 to 2 mm wide. The last turn is straight or only rises slightly. The apex is bluntly rounded. The shell is thin and the color of the case ranges from yellowish to maroon. The embryonic casing is smooth, the postembryonic convolutions have fine, irregular radial folds. The mouth is rounded with wide, curved edges. The mouth reinforcement consists of two "teeth", a parietal lamella and a columellar lamella, as well as an angular tubercle, which can, however, also be missing. In juvenile animals there is a columellar lamella and some palatal folds that appear as spiral lines through the housing. They are reabsorbed in the adult stage. The navel is narrow and open.

In the genital apparatus, the male and female tracts divide very early, and there is virtually no egg ladder. The thin sperm duct (vas deferens) is therefore very long; it opens apically into the comparatively very short epiphallus . This swells very quickly after the confluence of the spermatic duct; the diameter decreases by half at the epiphallus / penis transition. A comparatively long, conical blind sack (“caecum” or penile blind sack) sits at the transition from the epiphallus to the penis. The penis is comparatively very long and about three times the length of the epiphallus. The very long penile appendix starts around the beginning of the lower third of the penis. The lower part of the penis appendix is ​​thick (about the thickness of the penis), after which the thickness initially decreases by half. The following part is very long and thin, the end part is again very strong, swollen club-shaped. The retractor muscle divides into two strands, one of which attaches to the end of the strongly thickened lower part of the penile appendix, the other strand attaches to the epiphallus / penis transition between the epiphallus and the penile blind sac.

The upper fallopian tube is transformed into the "uterus" in which the eggs are held back until the young are fully developed. Due to the early separation of the spermatic and fallopian tubes, the free fallopian tube is very long overall. The spermathec branches off from the fallopian tube just before the atrium. As a result, the vagina is virtually missing. The stem of the sperm library is very long. The seminal vesicle is comparatively small and comes to lie in the area of ​​the prostate and the albumen gland.

Geographical distribution

The species of the genus Lauria occur on the Atlantic islands of Madeira , the Azores and the Canaries , in southern and western Europe, on the Crimean peninsula, in the Caucasus , Kopet-Dag , in Asia Minor, in the Middle East and on the Arabian Peninsula. Today one species has been anthropogenic almost worldwide.

Taxonomy

The genus Lauria was proposed by John Edward Gray in 1840. Type species is Pupa umbilicata Draparnaud, 1801, a more recent synonym of Lauria cylindracea (Mendes da Costa, 1778). Fauna Europaea divides the genus into two sub-genera Lauria (Lauria) and Lauria (Senilauria) Pilsbry, 1928. Schileyko (1998), however , regards Senilauria as an independent genus, while Welter Schultes does not use any sub-genera and regards Senilauria as a younger synonym of Lauria .

supporting documents

literature

  • 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 (p. 83)

Individual evidence

  1. ^ William Turton, John Edward Gray: A manual of the land and fresh-water shells of the British Islands, with figures of each of the kinds. A new edition, thoroughly revised and much enlarged. Pp. I-IX, 1-324, London, Longman, Orme, Brown, Green & Longmans Online at www.biodiversitylibrary.org (p. 193).
  2. ^ Fauna Europaea: Lauria JE Gray 1840
  3. ↑ 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)
  4. ↑ David T. Holyoak, Geraldine A. Holyoak: Una nueva especie de Lauria (Gastropoda, Lauriidae) de las Islas Canarias. Iberus, 27 (2): 1-5, 2009 ISSN  0212-3010

Web links

Commons : Genus Lauria  - collection of images, videos and audio files