Pseudofusulus varians

Pseudofusulus varians
Common and albinistic colour forms of Pseudofusulus varians
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Heterobranchia

clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
informal group Sigmurethra

Superfamily: Clausilioidea
Family: Clausiliidae
Subfamily: Clausiliinae
Tribe: Clausiliini[1]
Genus: Pseudofusulus
Nordsieck, 1977[2]
Species: P. varians
Binomial name
Pseudofusulus varians
(C. Pfeiffer, 1828)[3]
Synonyms

Clausilia varians Pfeiffer, 1828

Pseudofusulus varians is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae.

Genus Pseudofusulus is monotypic genus (contains one species only) with Pseudofusulus varians as its type species.

It is a relict species from Atlantic period of the Holocene, inhabiting exclusively nature beech and scree forests in Europe.[4]

Distribution

The distribution of this species is Eastern-Alpine and Western-Carpathian.[5] The type locality is High Alps in Styria, Austria.[3]

The key area of its range are Western Alps (from the south-western part of Alps to Croatia, and also to Dolomites in the southern Tyrol).[4]

shells of Pseudofusulus varians

Description

The shell is horny or greenish brown and finely ribbed.[7] The shell has 9-10 whorls.[7] The apertural margin is detached.[7] Columellaris is deep inside and forked, hardly visible in a perpendicular view.[7] Palatal wall is white and prominent.[7] There is no lunula.[7] Subcolumellaris is very close to basal furrow, visible in an oblique view.[7] Clausilium is not very concave.[7]

The width of the shell is 2.2–3 mm.[7] The height of the shell is 9–12 mm.[7]

Habitat

Pseudofusulus varians is very exacting on the quality of its environment and its populations are small and quite scattered in the whole of its range.[4]

It lives in virgin-like forests[5] and old-growth forest with fallen dead wood (coarse woody debris) in montane and submontane.[4] It is found in humid and shady habitats in woods, under ground litter and stones, in mountains.[7] In the Czech Republic it is strictly associated with trees, restricted to undisturbed and hardly accessible natural beech forests.[7] Pseudofusulus varians is strictly dendrophilous species, so the main threat is dead wood removing and clearcutting.[4]

As it is endangered in the whole Europe, it is very important to protect its modern sites.[4]

References

This article incorporates public domain text from the reference[7] and CC-BY-3.0 text from the reference[4]

  1. "Clausiliini". Fauna Europaea, last update 27 January 2011, accessed 27 April 2011.
  2. (German) Nordsieck H. (1977). "Zur Anatomie und Systematik der Clausilien, XVIII. Neue Taxa rezenter Clausilien". Archiv für Molluskenkunde 108(1/3): 73-107. page 96.
  3. 3.0 3.1 (German) Pfeiffer C. (1828). "Naturgeschichte deutscher Land- und Süsswasser-Mollusken". Dritte Abtheilung. pp. I-VI, 1-84 pp., Taf. I-VIII. Weimar. (Landes-Industrie-Comptoir). p. 40, Taf. 7, Fig. 24-25.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 (Czech) Lacina A. (2011). "Poznámky k ekologii, rozšíření a ochraně vřetence horského (Pseudofusulus varians) v České republice. [Notes to the ecology, distribution and protection of Pseudofusulus varians in the Czech Republic]". Malacologica Bohemoslovaca 10: 18-23. PDF.
  5. 5.0 5.1 (Czech) Lacina A. & Horsák M. (2009). "Jak se vede vřetenatci horskému – z červené knihy našich měkkýšů" ["Is the land Snail Pseudofusulus varinas Doing Well? From the Czech Republic's Red Book of Molluscs"]. Živa, Praha LVII(2): 73-74. English abstract.
  6. (Czech) Ložek V. (1985). "Z červené knihy našich měkkýšů - je ohrožen vřetenec horský?". Živa 33: 221.
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 "Species summary for Pseudofusulus varians". AnimalBase, last modified 23 March 2011, accessed 27 April 2011.

External links

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