Eobania vermiculata
| Eobania vermiculata | |
|---|---|
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| Two shells of the species showing apical and apertural views | |
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| An unusually dark, subadult live individual of Eobania vermiculata | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Stylommatophora |
| Family: | Helicidae |
| Genus: | Eobania |
| Species: | E. vermiculata |
| Binomial name | |
| Eobania vermiculata (O. F. Müller, 1774)[1] | |
| Synonyms | |
| Helix vermiculata O. F. Müller, 1774 | |
Eobania vermiculata also known as Helix vermiculata, common name the "chocolate-band snail" is a species of large, air-breathing, land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the true snails or typical snails.
Eobania vermiculata is the type species of the genus Eobania.
Distribution
[edit]This species of large land snail is common in the Mediterranean area; its distribution ranges from eastern Spain to Crimea:
The nonindigenous distribution of Eobania vermiculata includes:
- This species has been introduced to southeastern Australia, where it is known as the chocolate-band snail.[4]
- One individual of this snail species was found living on a wall in Lewisham, London, England, in 2006.[5][6] It remains to be seen if a colony will establish itself or not.
- E. vermiculata has non-indigenous populations in Belgium, Germany, Hungary, the Netherlands, the US, Australia, Japan, South Africa, Egypt, Israel, Saudi Arabia, Jordan, and Iran.[7]
This species is already established in the US, and is considered to represent a potentially serious threat as a pest, an invasive species which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore, it has been suggested that this species be given top national quarantine significance in the USA.[8]
E. vermiculata is able to survive winters in the North-West European temperate zone, including Belgium and The Netherlands.[7]
Description
[edit]In this species the color of the shell is very variable. The background color can be whitish to greenish yellow, and the shell often has darker coloured bands or spots.[3] The ventral side of the shell frequently has two brown bands, and is whitish between the lowest band and the umbilicus.[3] The shell has 4-4.5 whorls.[3] The last whorl descends abruptly below the periphery of the shell.[3] The apertural margin is white, and is reflected (turned back)in adult shells, in juveniles this is true only on the columellar side.[3] The umbilicus is narrow and open in juveniles, only partly covered by the reflected columellar margin,; the umbilicus is however completely closed in adult shells.[3]
The width of the shell is 22–32 mm; the height of the shell is 14–24 mm.[3]
In northern Greece, the variability within the populations of this species seems to be lower than in southern Greece (Gávdos island: 24.5-33.5 m in diameter of adult shells, average 28–29 m, with no local variations in shell size).[3]
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Juveniles somewhat resemble the species Theba pisana (which also has a similar umbilicus); however Eobania vermiculata can be differentiated from that species by its much larger apex.[3]
Ecology
[edit]Eobania vermiculata live in a broad variety of habitats, usually in dry vegetation, mainly in coastal vicinity, also in agricultural crops.[3] It is very common in Crete, the species lives on practically every small island in the south Aegean.[3]
In northern Greece copulation takes place after the first rainfalls in autumn.[3] These snails create and use love darts as part of their mating behavior. Around 70 eggs per snail are laid 20 days later.[3] The size of the egg is 4.1 × 3 mm.[9] Juveniles hatch shortly after and grow about 12–13 mm in diameter per year for 2 years (growth is usually restricted to February to June in northern Greece, in Crete this period ends already in May).[3] Maturity is reached after 2 years when the diameter reaches 25 mm, the umbilicus becomes closed and the apertural margin becomes reflected.[3] Snails reach 29–30 mm diameter in May/June of the second year in northern Greece (in April in Crete), reaching a maximum diameter (33 mm) may take 5 years or more, but mortality increases greatly after 2 years.[3]
About 20% of the snails in a population survive to lay eggs in the 3rd year, 5% of the snails lay eggs again in the 4th year.[3] The mortality rates decrease with age.[3] The animals hibernate (in northern Greece) or aestivate (in Crete), but juveniles and adults show differences in their behaviour.[3] Adults dig into the soil and build an epiphragm, while juveniles search protected places under stones or leaves of low plants.[3]
Human use
[edit]The species is used for food. It is commercialized and exported from Greece to France, which led Lazaridou-Dimitriadou & Kattoulas (1981)[10] to propose restrictions on the size and seasons of collection for this species.[3]
References
[edit]This article incorporates public domain text from the reference.[3]
- ^ Müller O. F. (1774). Vermivm terrestrium et fluviatilium, seu animalium infusoriorum, helminthicorum, et testaceorum, non-marinorum, succincta historia. Volumen alterum. pp. I-XXVI [= 1-36], 1-214, [1-10]. Havniae & Lipsiae. (Heineck & Faber).
- ^ a b Commonwealth of Australia. (April 2002). "Citrus Imports from the Arab Republic of Egypt. A Review Under Existing Import Conditions for Citrus from Israel" Archived 9 January 2009 at the Wayback Machine. Agriculture, Fisheries and Forestry, Australia. Caption: Gastropods, page 12 and Appendix 2.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z "Species summary for Eobania vermiculata". AnimalBase. Last modified 31 August 2010, accessed 13 October 2010.
- ^ Eobania vemiculata. accessed 4 November 2008.
- ^ Notton D. (2006). "Eobania vermiculata in the UK". Mollusc World 11: 6.
- ^ JRS (December 2006). "Aliens: what can they teach us?" Archived 29 June 2011 at the Wayback Machine. The Archeo+Malacology Group Newsletter (10): page 7.
- ^ a b Ronsmans J. & Van den Neucker T. (2016). A persistent population of the chocolate-band snail Eobania vermiculata (Gastropoda: Helicidae) in Belgium. Belgian Journal of Zoology 146(1):66–68.
- ^ Cowie R. H., Dillon R. T., Robinson D. G. & Smith J. W. (2009). "Alien non-marine snails and slugs of priority quarantine importance in the United States: A preliminary risk assessment". American Malacological Bulletin 27: 113-132. PDF Archived 16 June 2016 at the Wayback Machine.
- ^ Heller J. (2001). Life History Strategies. In: Barker G. M. (ed.) The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, ISBN 0-85199-318-4. 1-146, cited page: 428.
- ^ Lazaridou-Dimitriadou M. & Kattoulas M. (1981). "Contribution a l'étude de la biologie et de la croissance des escargots commercialisés en Grèce: Eobania vermiculata (Müller) et Helix aspersa Müller". Haliotis 11: 129-137.
External links
[edit]
- Ronsmans J. & Van den Neucker T. (2016). A persistent population of the chocolate-band snail Eobania vermiculata (Gastropoda: Helicidae) in Belgium. Belgian Journal of Zoology 146(1):66–68. PDF