Native to: central Europe (Austria to Transylvania) (Yildirim & Kebapçi 2004); probably S Alps and N Balkans (Wiktor 1987)
Non-native to: Belgium, Czech Republic, Iceland, Poland, Turkey, UK (Yildirim & Kebapçi 2004), USA (introduced to Washington, DC and Philadelphia urban parks) (Reise et al. 2005).
External: Mantle <1/3 body length; forms a "C" when contracted; gray-brown body with somewhat darker dorsum on preserved specimens, with black spots all over and concentrated on top of dorsum and mantle; dark dorsum, to black or dark brown; gray-yellow or orange keel; dark horseshoe groove in mantle, groove along foot sole, and grooves in dorsum; mantle may be lighter than dorsum; gray edge of pneumostome; keel extends from tail tip to mantle; 3-part sole gray or orange-gray with a dark central section; thick, clear mucus that can form threads, orange to yellow transparent, becoming milky when perturbed (Quick 1960; Kerney & Cameron 1979; Wiktor 1996; Yildirim & Kebapçi 2004).
External: Internal shell 3 x 1.25 mm, brown; longish epiphallus and penis; club-shaped epiphallus about equal in length to penis; rounded penis; strong penial retractor muscle; oviduct tubular; vagina about width of oviduct and very short; wide, long spermatheca duct, and cylindrical spermatheca; two white, lobular accessory glands attached closely to vagina by multiple ducts; no atrial stimulator; long, thin spermatophore that is twisted, covered with spines, and ~16 mm long (Quick 1960; Kerney & Cameron 1979; Wiktor 1987, 1996).
Differs from - M. gagates and T. sowerbyi as body only partly contracts and forms a "C", no stimulator in atrium, longer spermathecal duct; 16 mm spermatophore thin and twisted (Quick 1960).
Eggs: 2.9 x 2.25 mm; yellow, leathery (Quick 1960).
Juveniles: 4.5 mm long, yellow-gray with keel at hatching (Quick 1960).
To 70 mm long extended; preserved: to 42 mm long, 5 mm wide, 11 mm long mantle (Wiktor 1987).
M. gagates, T. sowerbyi
Occurs in shrubland, cultivated land, gardens, roadsides, wastelands, rocky habitats, and sometimes forest; synanthropic where introduced; to 1500 m in Bulgaria; takes shelter under rocks, leaf litter, and detritus (Quick 1960; Wiktor 1983; Yildirim & Kebapçi 2004).
T. budapestensis is a pest species (Kerney & Cameron 1979) that consumes roots (Chatfield, 1976).
Molecular Biology and Genetics
Barcode data: Tandonia budapestensis
There are 2 barcode sequences available from BOLD and GenBank. Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Tandonia budapestensis
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
This slug is basically dark brownish grey, with a keel of a brighter color. The body is yellowish-grey to brown or dark grey, with numerous black spots, so that the slug may appear to be evenly black-brown, slightly lighter at the sides. The animal is very slender, gradually narrowing posteriorly. The mantle length is less than 1/3 of the body length. There are blurry black bands on the sides of the mantle. The keel is prominent, light, and reaches the mantle. The head and neck are blackish.The sole is narrow and cream with brown or orange hue. The body mucus is usually colourless, thick and sticky but it is yellowish when the slug is irritated.
Reproductive system: The penis is rounded, wider than and approximately as long as the epiphallus. The vas deferens opening is clearly asymmetrically at the posterior end of epiphallus. Therer is a small simple papilla inside the penis. The spermatheca duct is usually thick; the vagina and atrium are short, the vagina accessory glands are two lobe-like objects connected to the vagina by thin ducts. The spermatophore is thin, 16 mm long, covered almost entirely with short spines.
It occurs in the following countries, amongst others:
- British Isles: introduced before 1880: Great Britain and Ireland
- Czech Republic - least concern (LC)
This species is already established in the USA, 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.
This slug mainly lives in secondary, anthropogenous (man-made) habitats, such as farmland. The habitat of Tandonia budapestensis includes parks, gardens, ruins and cultivated fields. It lives as a synanthrope. It occur in natural environments in Britain only where human disturbance is involved. In south Bulgaria it is found usually between 300 and 1000 m, but locally up to 2200 m. It requires humidity and is active at night. It buries into heavy soils.
The biology of the species was reviewed by Reise et al. (2006). In Britain the copulation of this slug species takes place from November to January; in Central Europe from April to autumn. Slugs may copulate several times in their life. Copulation begins usually at night and may last 15 hours or more; everted genitalia are visible between the partners. In Britain, juveniles hatch in April or May, and maturity is reached in the autumn. Up to more than 20 eggs are laid at a time. In Central Europe, eggs, sub-adults and adults pass the winter.
This species is noxious to crops, in lowland England particularly to potatoes. This species is a pest in crops of root vegetables.
This article incorporates public domain text from the reference.
- 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Cited 2 March 2007.
- Hazay J. (1880). "Die Molluskenfauna von Budapest". Malakozoologische Blätter (Neue Folge) 3["1881"]: 1-69, 160-183, Taf. I-IX [= 1-9]. Cassel.
- "Species summary for Tandonia budapestensis". AnimalBase, last modified 14 February 2009, accessed 26 August 2010.
- Juřičková L., Horsák M. & Beran L. (2001). "Check-list of the molluscs (Mollusca) of the Czech Republic". Acta Soc. Zool. Bohem. 65: 25-40.
- Dvořák L., Čejka T. & Horsák M. (2003) "Present knowledge of distribution of Tandonia budapestensis (Hazay, 1881) in the Czech and Slovak Republics (Gastropoda: Milacidae)" Malakológiai Tájekoztató (Malacological Newsletter) 21: 37-43. PDF.
- Barker, G.M. 1999. Naturalised terrestrial Stylommatophora (Mollusca: Gastropoda). Fauna of New Zealand No. 48. Manaaki Whenua Press: Lincoln, NZ. PDF
- Reise H., Hutchinson J. M. C. & Robinson D. G. (2006). "Two introduced pest slugs: Tandonia budapestensis new to the Americas, and Deroceras panormitanum new to the Eastern USA". Veliger 48: 110-115. PDF
- 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.
- Janus, Horst (1965). The young specialist looks at land and freshwater molluscs, Burke, London.
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