Banana Slug

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Ariolimax columbianus
Family

Arionidae
Species

Ariolimax columbianus (Gould, 1851)
Common Name

Pacific banana slug
Description

This robust slug can attain a length of 185 to 260 mm and may weigh up to 72 g at maturity. This species is normally yellow in color; however, several color morphs exists, that range from white to tan-green, red-brown, brown-green, olive green, slate green and ochre yellow. The mantle and body of the slug is usually of uniform color; however, the mantle in any of the color morphs may possess dark-brown to black spots, while the body remains a uniform color. In some specimens, this pattern is reversed and the body possess spots that are not present on the mantle. In some specimens, the black blotches occur simultaneously on the mantle and body and may even coalesce to give the slug a solid black. The juveniles of this species are finely speckled. This slug has a caudal mucus pore with the pneumostome (breathing pore) located behind the midpoint of the often finely granulated mantle. The keel appears undulating in strongly contracted individuals and does not reach the mantle. The sole of the foot is usually much wider than the body."