Eobania vermiculata

This species of large land snail is common in the Mediterranean area; its distribution ranges from eastern Spain to Crimea:

• Israel[2]
• Egypt[2]
• eastern Spain[3]
• eastern Bulgaria[3]
• southern Greece[3]
• Crimea in Ukraine[3]

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]

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 mm in diameter of adult shells, average 28–29 mm, with no local variations in shell size).[3]

Apical view of a shell of Eobania vermiculata

Five views of a shell of Eobania vermiculata

Five views of a cream-coloured shell of Eobania vermiculata

Five views of a white shell of Eobania vermiculata

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]

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]

Drawing of love dart of Eobania vermiculata. Cross-section (on the left) and lateral view (on the right).

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]

A group of Eobania vermiculata from Tunisia

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]

This article incorporates public domain text from the reference.[3]

Wikimedia Commons has media related to Eobania vermiculata.

• 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