Arion circumscriptus

Common in NW Europe, to S Scandanavia and E Russia (Kerney & Cameron 1979; Sysoev & Schileyko 2009).

Non-native to: USA and S Canada (Chichester & Getz 1969).

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

External: Dark gray or brown, little speckles of black on mantle, lighter on sides; dark bands on sides of body and mantle; bell-shaped in cross section when contracted; slight keel; white sole; clear mucus (Kerney & Cameron 1979).

Internal: Pigmented epiphallus (Kerney & Cameron 1979); atrium 2x long as wide; spermatheca duct and oviduct equally thick (Wiktor 1983).

Similar to A. fasciatus and A. silvaticus, but darker, and has a much more pigmented epiphallus (Kerney & Cameron 1979). Relative to A. silvaticus, A. circumscriptus has a longer body, spots on mantle, fuzzy lower edge of lateral bands, longer atrium, smaller and pigmented epiphallus (Wiktor 1983).

30-40 mm long (Kerney & Cameron 1979).

Arion fasciatus, A. silvaticus

Habitat Type: Terrestrial

Lowland deciduous forest; valleys, rivers, etc. that provide moist, shady habitat; takes shelter in leaf litter (Wiktor 1996).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Feeds on live and decaying plants (Getz 1959).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

Comments: In New York, Hotopp and Pearce (2007) report it from five widely separated counties as introduced. Forsyth (2005) documented it in the Upper Fraser Basin of central British Columbia at a few sites but is also known from around Canim Lake, Greater Vancouver, southern Vancouver Island, the Queen Charlotte Islands, and the Bulkley Valley at Smithers. Most recently, it was discovered in the Ktunaxa Traditional Territory in southeastern British Columbia (which extends from near Canada - U.S. border north to about 50 km north of Cranbrook) (Ovaska and Sopuck, 2009).

Not aggressive (Rollo & Wellington 1979).

Usually secluded in their habitat. Respond strongly to and emerge with rain and moisture gradients, relatively intolerant of dessication and high temperatures (Getz 1959).

In Michigan, adults are present in spring and summer, and they lay eggs in late summer until hibernation. A. circumscriptus may live 2-3 years (Getz 1959).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

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.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 3
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: G5 - Secure