Arion (Carinarion) fasciatus (Nilsson, 1823)
Aggregations occur with during dry conditions and unfavorable temperatures (Rollo & Wellington 1981).
Arion circumscriptus, Arion silvaticus.
External: Gray on dorsum, paler at sides and white toward foot fringe, dark bands on sides of body and mantle and with yellow below stripes; slight keel formed by larger tubercles along dorsal mid-line; bell-shaped in cross-section; opaque gray-white sole; clear mucus; (Quick 1960; Kerney & Cameron 1979).
Internal: Dark ovotestis, pinkish spermoviduct, yellow atrium; long spermatheca with short, wide duct; epiphallus with swollen ring around its base; long, thin oviduct; 4 mm long spermatophore with coiled anterior part, wider behind (Quick 1960).
A. circumscriptus and A. silvaticus are similar, but no yellow, smaller, and have a wider oviduct. A. subfuscus are similar but have colored body mucus and different internal anatomy (Kerney & Cameron 1979); relative to A. silvaticus, is flatter, lighter in color, with orange/yellow stripe under dark side stripes, conical atrium, larger epiphallus with swelling at its base, thicker spermatheca duct (Wiktor 1983).
Eggs: 3 x 2 mm, yellow or light brown, translucent; clutches to 30 eggs; laid late spring to fall (Quick 1960).
Juveniles: 5 mm long at hatching, yellow-gray, with a pale dorsal keel that diminishes with age (Quick 1960).
Medium, 40-50 mm long (Kerney & Cameron 1979). .
Native to: NW Europe (Kerney & Cameron 1979); north to Scandinavia, west to France, and east to W Russia, Ukraine, Romania (Quick 1960; Likharev & Schileyko, MS; Serlova 2006; in Sysoev & Schileyko 2009).
Non-native to: Iceland, North America (Quick 1960).
Preyed upon by lampyrid beetle larvae (Schwalb 1961, in Stephenson & Knutson 1966).
A. ater is a synanthrope that inhabits "ecotones" (Chichester & Getz 1973) such as gardens, parks, wastelands, fields, cemeteries, near buildings, garbage dumps (Kerney & Cameron 1979; Wiktor 1996). Takes shelter in leaf litter and moss or under logs and rocks (Quick 1960). Does not spread far into undisturbed habitat (Chichester & Getz 1969).
Probably feeds on fungus, "lettuce in lab" (Chichester & Getz 1973).