Eobania vermiculata
Encyclopedia
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.
area and it ranges from eastern Spain
to the Crimea
:
Nonindigenous distribution of Eobania vermiculata include:
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 effect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine
significance in the USA.
is very variable, whitish to greenish yellow, often with colour bands or spots. Lower side is frequently with two brown bands and whitish between lowest band and umbilicus. The shell has 4-4.5 whorls
. The last whorl is descending abruptly below periphery. The apertural margin is white, reflected in adult shells, in juveniles only at columellar side. The umbilicus is narrow and open in juveniles, partly covered by the reflected columellar margin, completely closed in adult shells.
The width of the shell is 22–32 mm. The height of the shell is 14–24 mm.
In northern Greece variation 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).
Juveniles differ from Theba pisana
(with likewise umbilicus) by the larger size of the apex
.
In northern Greece copulation takes place after the first rainfalls in autumn. These snails create and use love dart
s as part of their mating behavior. Around 70 eggs per snail are laid 20 days later. The size of the egg is 4.1 × 3 mm. 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). Maturity is reached after 2 years when the diameter reaches 25 mm, the umbilicus becomes closed and the apertural margin becomes reflected. 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.
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. The mortality rates decrease with age. The animals hibernate (in northern Greece) or aestivate (in Crete), but juveniles and adults show differences in their behaviour. Adults dig into the soil and build an epiphragm
, while juveniles search protected places under stones or leaves of low plants.
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
the "chocolate-band snail" is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of large, air-breathing, land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
, a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
pulmonate gastropod mollusk in the family Helicidae
Helicidae
The Helicidae, sometimes known as the typical snails, are a taxonomic family of small to large, air-breathing, land snails. In other words, they are terrestrial pulmonate gastropod mollusks....
, the true snails or typical snails.
Eobania vermiculata is the type species of the genus Eobania.
Distribution
This species of large land snail is common in the MediterraneanMediterranean Basin
In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation...
area and it ranges from eastern Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
to the Crimea
Crimea
Crimea , or the Autonomous Republic of Crimea , is a sub-national unit, an autonomous republic, of Ukraine. It is located on the northern coast of the Black Sea, occupying a peninsula of the same name...
:
- Israel
- Egypt
- eastern Spain
- eastern Bulgaria
- southern Greece
- CrimeaCrimeaCrimea , or the Autonomous Republic of Crimea , is a sub-national unit, an autonomous republic, of Ukraine. It is located on the northern coast of the Black Sea, occupying a peninsula of the same name...
Nonindigenous distribution of Eobania vermiculata include:
- This species has been introduced to southeastern AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, where it is known as the chocolate-band snail. - One individual of this snail species was found living on a wall in LewishamLondon Borough of LewishamThe London Borough of Lewisham is a London borough in south-east London, England and forms part of Inner London. The principal settlement of the borough is Lewisham...
, LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, EnglandEnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, in 2006. It remains to be seen if a colony will establish itself or not.
This species is already established in the USA, and is considered to represent a potentially serious threat as a pest, an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
which could negatively effect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine
Quarantine
Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. The word comes from the Italian quarantena, meaning forty-day period....
significance in the USA.
Description
The color of the shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is very variable, whitish to greenish yellow, often with colour bands or spots. Lower side is frequently with two brown bands and whitish between lowest band and umbilicus. The shell has 4-4.5 whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
. The last whorl is descending abruptly below periphery. The apertural margin is white, reflected in adult shells, in juveniles only at columellar side. The umbilicus is narrow and open in juveniles, partly covered by the reflected columellar margin, completely closed in adult shells.
The width of the shell is 22–32 mm. The height of the shell is 14–24 mm.
In northern Greece variation 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).
 |
 |
Juveniles differ from Theba pisana
Theba pisana
Theba pisana, common names the white garden snail, the sand hill snail, white Italian snail, the Mediterranean coastal snail, or simply the Mediterranean snail, is an edible species of medium-sized air-breathing land snail, a pulmonate gastropod mollusk in the family Helicidae...
(with likewise umbilicus) by the larger size of the apex
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
.
Ecology
Eobania vermiculata live in a broad variety of habitats, usually in dry vegetation, mainly in coastal vicinity, also in agricultural crops. It is very common in Crete, the species lives on practically every small island in the south Aegean.Love dart
A love dart is a hard, long, sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are made in sexually mature animals only, and are used as part of the sequence of events during courtship, before actual mating takes place...
s as part of their mating behavior. Around 70 eggs per snail are laid 20 days later. The size of the egg is 4.1 × 3 mm. 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). Maturity is reached after 2 years when the diameter reaches 25 mm, the umbilicus becomes closed and the apertural margin becomes reflected. 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.
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. The mortality rates decrease with age. The animals hibernate (in northern Greece) or aestivate (in Crete), but juveniles and adults show differences in their behaviour. Adults dig into the soil and build an epiphragm
Epiphragm
An epiphragm is a temporary structure which can be created by many species of shelled, air-breathing land snails, terrestrial pulmonate gastropod mollusks. It can also be created by freshwater snails when temporary pools dry up....
, while juveniles search protected places under stones or leaves of low plants.