Arion fasciatus
Encyclopedia
Arion fasciatus, common name the Orange-banded Arion, is a species
of air-breathing, completely shell
-less, land slug
, a terrestrial
pulmonate gastropod mollusk in the family Arionidae
, the round-back slugs, first described by Sven Nilsson
in 1823.
, but spread to other cool, wet climates, including the British Isles
, Canada
and the Northern United States
. They originally got across the Atlantic Ocean
during the colonial era. These slugs are generally found in ecotonal
habitats.
with a head, mantle
, and foot.
These slugs have two sets of retractable tentacles on their heads. The upper pair have light sensing organs, and the lower two are used to smell. These slugs have a mantle that covers much of the top of the first third of the body, with its pneumostome
located on the back right portion of the mantle.
The foot has three sections horizontally across, and in the middle, on the head, is where the mouth and radula
is. The orange banded arion has a darkened stripe that extends along the entire body and mantle length on both sides of the body, and is gray, off-white, or tan, with a very light colored foot.
The Arion fasciatus is about six centimeters in length when moving, secreting a clear mucus
behind it. However, when disturbed, the mucus becomes denser and stickier. A study found that the thicker mucus can prevent predation by Carabid beetles
, but that this mucus becomes exhausted after three minutes of stimulation. It then takes up to a day to get mucus production up to pre-attack levels, leaving the slug susceptible to other predators.
layer. This is not to say that the orange-banded arion does not eat fresh vegetable matter.
This study also found that the diet of the orange-banded arion is variable throughout the year. For example, an increase in animal material during May and June. The hypothesis is that during the colder months slugs don't move much under the leaf litter, and take in a lot of leaves where the chlorophyll
as already broken down, and during the warmer months, they take advantage of the earthworms and small arthropods who have high mortality rates.
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 air-breathing, completely shell
Mollusc shell
The mollusc shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes...
-less, land slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
, 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 Arionidae
Arionidae
Arionidae, common name the "roundback slugs" or "round back slugs" are a taxonomic family of air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the superfamily Arionoidea.- Distribution :...
, the round-back slugs, first described by Sven Nilsson
Sven Nilsson
Sven Nilsson was a Swedish zoologist and archaeologist, who was director of the Naturhistoriska Riksmuseet , professor of Natural history at Lund University , and rector of the university...
in 1823.
Distribution
Arion fasciatus are originally from Northern EuropeNorthern Europe
Northern Europe is the northern part or region of Europe. Northern Europe typically refers to the seven countries in the northern part of the European subcontinent which includes Denmark, Estonia, Latvia, Lithuania, Norway, Finland and Sweden...
, but spread to other cool, wet climates, including the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and the Northern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. They originally got across the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
during the colonial era. These slugs are generally found in ecotonal
Ecotone
An ecotone is a transition area between two biomes but different patches of the landscape, such as forest and grassland. It may be narrow or wide, and it may be local or regional...
habitats.
Description
Arion fasciatus is very similar to most slugs in almost all ways. They are hermaphroditicHermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...
with a head, mantle
Mantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
, and foot.
These slugs have two sets of retractable tentacles on their heads. The upper pair have light sensing organs, and the lower two are used to smell. These slugs have a mantle that covers much of the top of the first third of the body, with its pneumostome
Pneumostome
The pneumostome is a feature of the external body anatomy of an air-breathing land slug or land snail. It is a part of the respiratory system of gastropods....
located on the back right portion of the mantle.
The foot has three sections horizontally across, and in the middle, on the head, is where the mouth and radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
is. The orange banded arion has a darkened stripe that extends along the entire body and mantle length on both sides of the body, and is gray, off-white, or tan, with a very light colored foot.
The Arion fasciatus is about six centimeters in length when moving, secreting a clear mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
behind it. However, when disturbed, the mucus becomes denser and stickier. A study found that the thicker mucus can prevent predation by Carabid beetles
Ground beetle
Ground beetles are a large, cosmopolitan family of beetles, Carabidae, with more than 40,000 species worldwide, approximately 2,000 of which are found in North America and 2,700 in Europe.-Description and ecology:...
, but that this mucus becomes exhausted after three minutes of stimulation. It then takes up to a day to get mucus production up to pre-attack levels, leaving the slug susceptible to other predators.
Feeding habits
A study was done on the eating habits of Arion fasciatus, which found that it does not find fresh leaves as palatable, likely because they generally feed under the leaf litterDetritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
layer. This is not to say that the orange-banded arion does not eat fresh vegetable matter.
This study also found that the diet of the orange-banded arion is variable throughout the year. For example, an increase in animal material during May and June. The hypothesis is that during the colder months slugs don't move much under the leaf litter, and take in a lot of leaves where the chlorophyll
Chlorophyll
Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...
as already broken down, and during the warmer months, they take advantage of the earthworms and small arthropods who have high mortality rates.