Ariolimax columbianus
banana slug
(Also: Pacific banana slug)

The Banana Slug can be found along the Pacific Coast. Its populations reach from as far north as Alaska to as far South as California. The heaviest concentration of the Banana Slug is found in California. (Branson 1996, Hill 1997)

Banana Slugs live in the floors of forests in the Pacific Northwest. Because they respire through their skin, Banana Slugs require a moist environment to live. Banana Slugs serve as decomposers in forests. They break down plant materials. They also spread seeds and spores while eating. They spend much of their time during the day in moist, dark areas like under logs or other forest debris. (Branson 1996, Hill 1997)

The Banana Slug is the second largest slug. It can reach up to a length of 25 cm. The majority of Banana Slugs can easily be identified by their resemblence to a banana. They have yellow bodies with brown spots. Some Banana Slugs can be found with green, brown, or white bodies. The coloration of Banana slugs can change accordingly with their diet and the amount of moisture in their environment. The bodies of Banana Slugs have a muscular foot for locomotion. They also posses a hump on their back and a mantle. Banana Slugs have lungs that open to the outside through a pneumostone for respiration located on the right side of their mantle. Banana Slugs have two pairs of tentacles. The larger of the two pairs of tentacles are used to sense the brightness of light. The second pair are used to sense smells. The Banana Slug is able to retract both pairs of tentacles to protect them from the surrounding environment. Banana Slugs are covered with a slime that serves many purposes. (Branson 1996, Hill 1997, Murphy 1967, Nichols and Cooke 1979)

One disitinctive behavior of the Banana Slug is how it gnaws off its penis when disengaging from intercourse. Another interesting behavior that the Banana Slug engages in is estivation. The slug buries itself in forest debris, secretes a protective layer of mucus, and becomes inactive. Estivation occurs during hot, dry periods to prevent the slug from dessication. Banana Slugs also hibernate when the temperature gets very low. (Branson 1996, Hill 1997, Murphy 1967)

Banana Slugs are herbivores. They eat leaves, dead plant materials, fungi, and animal droppings. Banana Slugs favor mushrooms over other foods. Banana Slugs eat their food using their radula. A radula is made up of many rows of teeth used for grinding up food particles. (Branson 1996, Hill 1997, Grzimek 1972)

Banana slugs are sometimes viewed as pests by gardeners when they eat garden plants and flowers. (Hill, 1997)

The slime that the Banana Slug excretes serves many purposes. One function of the slime is for respiration. Respirtaion occurs partially on the skin of slugs. Gas exchange can only take place if the skin is moist. The slime also serves to attract mates to the slug. The third function of the slime is locomotion. The last function of the slime is for protection. The slime becomes an anasthetic when it comes in contact with a moist surface. This deters predators from eating the Banana Slug. (Hill 1997)