Two-toothed coastal snail

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Two-toothed coastal snail
Two-toothed coastal snail (Leucophytia bidentata)

Two-toothed coastal snail ( Leucophytia bidentata )

Systematics
Order : Lung snails (pulmonata)
Superfamily : Ellobioidea
Family : Coastal snails (Ellobiidae)
Subfamily : Ellobiinae
Genre : Leucophytia
Type : Two-toothed coastal snail
Scientific name of the  genus
Leucophytia
Winckworth , 1949
Scientific name of the  species
Leucophytia bidentata
( Montagu , 1808)
Mouse ears ( Myosotella myosotis ) (left) and sea ​​snail ( Leucophytia bidentata ) (right)

The two-toothed coastal snail ( Leucophytia bidentata ) is a type of snail from the family of the coastal snail (Ellobiidae) in the order of the pulmonary snail (Pulmonata). It is the only species of the monotypic genus Leucophytia .

features

The spindle-shaped housing is 5 to 7 mm high and 2 to 4 mm wide (5 to 6 mm high, 2 to 3 mm wide). It has 6 to 7 turns with a slightly curved, almost straight periphery and a very shallow seam. The last turn takes up almost 75% of the total case height. The apex is comparatively blunt. The mouth is elongated, crescent-shaped and compressed at the top, it reaches half to two thirds of the case height. A weak parietal callus is developed inside. Two folds are formed on the spindle wall, a smaller, tortuous fold near the mouth wall and a slightly larger fold above it. There is no navel. The housing varies only slightly in color, from horn-colored to red-brown.

The animals are protandric hermaphrodites; that is, they are first males and then later become females. In adult animals, the sex glands occupy the uppermost coils. A very thin conductor leads from the male sex glands through the digestive gland and then widens like a sac; the ladder is also very tortuous in this area. This area is used to store sperm during part of the year. It's bright white and opaque. Shortly before reaching the albumin gland, the ladder divides into a straight spermatic duct and a fallopian tube. From here on, the male and female genital systems are separated. A small spherical gland is formed at the branch point. The spermatic duct runs straight to the cylindrical, opaque prostate. The spermatic duct exiting the prostate is thin and tortuous and enters the (invaginated) penis at the apex. The penis is a little less than body length.

The fallopian tube, on the other hand, widens, becomes thick-walled and glandular, and forms the posterior mucous gland. At the lower end, the fallopian tube receives the secretions of the albumin gland. The tongue-shaped albumin gland is thick and stocky. The fallopian tube is long and widens distal to the vagina. The seminal vesicle is rounded and sits on a very long, thin stem.

Similar species

The two-toothed coastal snail ( Leucophytia bidentata ) is similar to the mouse ear ( Myosotella myosotis ). However, its case is a bit larger and thicker.

Geographical distribution and habitat

The range of the species stretches along the coast of the Eastern Atlantic from the British Isles to the Bay of Biscay. An individual find from Heligoland is available from the North Sea . The species occurs in the Mediterranean as far as western Turkey.

It is a semi-marine species that lives under stones and in the flushing material of the sea around the water splash mark. It is also often found on open beaches, less often in estuaries and tidal lagoons. It tolerates higher salt concentrations than the related mouse ear ( Myosotella myosotis ).

Way of life

The animals mostly live outside of the water and are detritus eaters. They reproduce in summer, from around June to September, and lay 12 to 30 eggs that are 0.6 to 0.7 mm in diameter. The clutches are attached to a solid surface. The young hatch after 14 to 16 days and become sexually mature (males) in autumn of the same year. They then live another two years during which they reproduce.

Taxonomy

The taxon was established in 1803 by George Montagu as Voluta bidentata . It is the type species of the monotypic genus Leucophytia Winckworth, 1949. This name is a replacement name for Leuconia Gray, 1840, a genus name that was preoccupied by Leuconia Grant in 1833 and is therefore invalid.

The genus Leucophytia is often considered a subgenus of Auriculinella Tausch, 1886. However, this genus is based on an Upper Cretaceous type species. The genre affiliation is therefore not certain for some authors. The Fauna Europaea therefore calls the taxon Leucophytis bidentata and has the following synonyms:

  • Auricula bivonae Philippi, 1844
  • Alexia Kobelti Caruana-Gatto, 1890
  • Alexia paivana L. Pfeiffer, 1866

supporting documents

literature

  • Michael P. Kerney, RAD 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. 77)
  • 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
  • John E. Morton: The Functional Morphology of the British Ellobiidae (Gastropoda Pulmonata) with Special. Reference to the Digestive and Reproductive Systems. Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences, 239 (661): 89–160, 1955 Stable URL at JSTOR (abstract)

Individual evidence

  1. ↑ Jürgen H. Jungbluth and Dietrich von Knorre: Trivial names of land and freshwater mollusks in Germany (Gastropoda et Bivalvia). Mollusca, 26 (1): 105-156, Dresden 2008 ISSN  1864-5127
  2. ^ Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 (p. 38)
  3. ↑ Thomas Ols Eggers, Steffen Förster: Living find of Leucophytia bidentata (Montagu 1808) (Pulmonata: Ellobiidae) near Helgoland. Writings on malacozoology from the House of Nature - Cismar, 13: 1–2, Cismar 1999 PDF
  4. ↑ George Montagu: Supplement to Testacea Britannica. SI-V, pp. 1–183, plates 17–30, London, White 1808 Online at www.biodiversitylibrary.org (p. 100)
  5. ↑ Fauna Europaea: Leucophytia bidentata (Montagu 1808)
  6. ↑ Rudolf Amandus Philippi: Enumeratio Molluscorum Siciliae Cum Viventium Tum In Tellure Tertiaria Fossilium, Quae In Itinere Suo Observavit. 2, 298 p., Berlin, Verlag Schroppius 1844 Online at Bayerische Staatsbibliothek digital (p. 118/9)
  7. ^ Alfredo Caruana-Gatto: Description of a new Alexia. Bulletin of the German Malakozoological Society, 22: 210–211, Frankfurt / Main 1890 Online at www.biodiversitylibrary.org (p. 210).
  8. ^ Ludwig Pfeiffer: Description of new Clausilien. Malakozoologische Blätter, 13: 146–154, Cassel 1866. Online at www.biodiversitylibrary.org

Web links

Commons : Leucophytia bidentata  - collection of images, videos and audio files