A Field Guide to the Snails of Lord Howe Island

143 Introduced species - slugs Family Agriolimacidae The Agriolimacidae is the largest slug family, with over 100 species. Agriolimacid slugs are relatively small, usually under 50 mm long. Their mantle is large, around one third of the body length or larger. They have a Holarctic distribution and some species are introduced worldwide. They are closely related to slug group Limacidae. Deroceras invadens Reise, Hutchison, Schunack & Schitt, 2011 Tramp Slug Shell. Internal. Animal. Size: Length = 20-35 mm. Colour: Dark brown to pinkish brown with a paler ring around the pneumostome. Shape: Mantle shield just under half body length; body small and narrow. Key distinguishing features. This species differs from the two limacid slugs in its smaller size, relatively larger mantle shield, pinkish colouration and lack of spots or stripes. Habitat and occurrence. Deroceras invadens was first recorded from Lord Howe Island in 2000. Only a few samples are known but they are distributed across the island, including the settlement area, Boat Harbour and the lower slopes of the southern mountains, indicating that this species is probably widespread. Remarks. This species was previously known as Deroceras panormitanum and is listed under this name in earlier works (e.g. Stanisic et al., 2010). Deroceras invadens