--- title: "Banana Slug (Ariolimax columbianus) | AnimalTracks.wiki" description: "A forest slug that may grow 20 cm long or more, coated in slime that numbs the mouth and tongue if swallowed." image: "https://animaltracks.wiki/images/animals/banana-slug-1.webp" published: "2026-10-11" updated: "2026-10-11" --- # Banana Slug (*Ariolimax columbianus*) > **Status**: Checked against 6 sources, listed under Sources below. > **Tagline**: A forest slug that may grow 20 cm long or more, coated in slime that numbs the mouth and tongue if swallowed. > **Soundtrack Vibe**: Post-Rock & Cinematic Orchestral // Caspian, "Sycamore" > **Soundtrack Links**: [Spotify](https://open.spotify.com/track/7Lp6gYzsrAvuv0qPdAJ2yA) > **Vibe Match**: Its slime is packed in granules that burst outside the body, and a trace of ATP, a jolt or cold sets them off. Sycamore holds back in a quiet build, then breaks open. ## Biological Superpowers & Stats - **Taxonomy**: *Ariolimax columbianus* - **Danger Level**: Low - **Conservation Status**: Not Evaluated ([IUCN Red List](https://www.iucnredlist.org/)) - **Superpower**: Slime that numbs the mouth and tongue if ingested - **Habitat**: Coastal rainforests from southeast Alaska to central California - **Diet**: Detritus (decomposing plant and animal parts and feces), plus fruit such as raspberries and blackberries - **Tags**: mollusc, invertebrate, forest ## Natural History & Behavior ## Slime on a hair trigger A banana slug is wrapped in slime, and the slime comes pre-packed. The skin releases giant mucin granules, which burst outside the cell and, once hydrated, form the typical slug mucus. In lab tests, a trace of a chemical called ATP made newly secreted granules rupture. Mechanical stress and cold did the same. > **Slime in a capsule** > The granules contain calcium, and calcium is released from a granule immediately before it bursts. The researchers propose that calcium shields the mucins, the long-chain molecules that make up slime, whose charges would otherwise stop them packing into the granule. The coat also guards the slug. One national park page calls the mucus a defence against predators, numbing the mouth and tongue if ingested. ## Yellow, long and heavy The Pacific banana slug lives in coastal rainforests from southeast Alaska to central California. It may grow to 7 inches (20 cm) long or greater. Some are bright yellow like a banana, while others are greenish or brown. Banana slugs as a group are the largest terrestrial slug in North America, with lengths exceeding 26 cm. That 26 cm figure covers the whole genus, which holds up to six species in California. How heavy? A two-year study of a backyard population in central California weighed 150 slugs, from 0.4 to 75.4 g. The yard was fed, though: the team kept a tray stocked with lettuce, melon rind and apples. Even so, a 107 g slug appeared on the deck in 2003, three years after the feeding ended. ## Fast growth, short life Those backyard slugs grew quickly. In both study years, slugs under a gram appeared in January and gained an average of 0.11 g a day. Weights peaked in summer, and in autumn slugs may lose up to 50% of their top weight. Then comes the surprise. Older reports gave a lifespan of 4 to 6 years, but the team found no evidence that their backyard slugs lived more than a little over two years. That is one population, so treat it as a local result. ## A forest recycler Banana slugs eat detritus, which means decomposing plant and animal parts as well as feces. They also eat fruit, including raspberries and blackberries, and may help spread seeds. Five slugs per square meter are not uncommon. Raccoons, garter snakes, waterfowl and salamanders are known to prey on them, and shrews or moles sometimes eat the young. Each slug is a hermaphrodite, carrying both sexes in one body. But they rarely fertilize themselves. ## Frequently Asked Questions ### How long do banana slugs live? Older reports said 4 to 6 years. A study that followed a backyard population in central California found no evidence that its slugs lived more than a little over two years. *(Source: [Pearson, Pearson & Ralph 2006]())* ### What do banana slugs eat? They are detritivores: they consume rotting plant and animal matter and feces. They also take fruit, including raspberries and blackberries. *(Source: [National Park Service, Redwood National and State Parks]())* ### Are banana slugs male or female? Both at once: a banana slug contains both sexes. Still, self-fertilization is rare. *(Source: [National Park Service, Redwood National and State Parks]())* ## Sources 1. [Banana Slug & Millipede. National Park Service, Redwood National and State Parks.]() 2. [Banana Slug. National Park Service, Muir Woods National Monument.]() 3. [Pearson, Pearson & Ralph (2006). Growth and Activity Patterns in a Backyard Population of the Banana Slug, Ariolimax columbianus. The Veliger.]() 4. [Verdugo et al. (1987). Molecular Mechanism of Mucin Secretion: I. The Role of Intragranular Charge Shielding. Journal of Dental Research.]() 5. [Deyrup-Olsen et al. (1992). Triggering by ATP of product release by mucous granules of the land slug Ariolimax columbianus. American Journal of Physiology-Cell Physiology.]() 6. [Genetti et al. (2025). Secrets of the Goo: The genome assembly of the Pacific banana slug, Ariolimax columbianus. Journal of Heredity.]() *Published October 11, 2026. Last updated October 11, 2026.* ```json { "@context": "https://schema.org", "@graph": [ { "@type": "Article", "@id": "https://animaltracks.wiki/animals/banana-slug/#article", "isPartOf": { "@id": "https://animaltracks.wiki/#website" }, "headline": "Banana Slug (Ariolimax columbianus) | AnimalTracks.wiki", "description": "A forest slug that may grow 20 cm long or more, coated in slime that numbs the mouth and tongue if swallowed.", "image": [ "https://animaltracks.wiki/images/animals/banana-slug-1.webp" ], "datePublished": "2026-10-11", "dateModified": "2026-10-11", "author": [ { "@type": "Organization", "name": "AnimalTracks.wiki Editorial Team", "url": "https://animaltracks.wiki" } ], "publisher": { "@type": "Organization", "@id": "https://animaltracks.wiki/#organization", "name": "AnimalTracks.wiki", "url": "https://animaltracks.wiki", "logo": { "@type": "ImageObject", "url": "https://animaltracks.wiki/icon-512.png" } }, "mainEntityOfPage": "https://animaltracks.wiki/animals/banana-slug/", "citation": [ { "@type": "CreativeWork", "name": "Banana Slug & Millipede", "url": "https://home.nps.gov/redw/learn/nature/banana-slug-and-millipede.htm", "publisher": { "@type": "Organization", "name": "National Park Service, Redwood National and State Parks" } }, { "@type": "CreativeWork", "name": "Banana Slug", "url": "https://www.nps.gov/muwo/learn/nature/banana-slug.htm", "publisher": { "@type": "Organization", "name": "National Park Service, Muir Woods National Monument" } }, { "@type": "CreativeWork", "name": "Growth and Activity Patterns in a Backyard Population of the Banana Slug, Ariolimax columbianus", "url": "https://archive.org/download/biostor-132882/biostor-132882.pdf", "author": "Pearson, Pearson & Ralph", "datePublished": "2006", "publisher": { "@type": "Organization", "name": "The Veliger" } }, { "@type": "ScholarlyArticle", "name": "Molecular Mechanism of Mucin Secretion: I. The Role of Intragranular Charge Shielding", "url": "https://doi.org/10.1177/00220345870660022001", "author": "Verdugo et al.", "datePublished": "1987", "isPartOf": { "@type": "Periodical", "name": "Journal of Dental Research" }, "identifier": "doi:10.1177/00220345870660022001" }, { "@type": "ScholarlyArticle", "name": "Triggering by ATP of product release by mucous granules of the land slug Ariolimax columbianus", "url": "https://doi.org/10.1152/ajpcell.1992.262.3.c760", "author": "Deyrup-Olsen et al.", "datePublished": "1992", "isPartOf": { "@type": "Periodical", "name": "American Journal of Physiology-Cell Physiology" }, "identifier": "doi:10.1152/ajpcell.1992.262.3.c760" }, { "@type": "ScholarlyArticle", "name": "Secrets of the Goo: The genome assembly of the Pacific banana slug, Ariolimax columbianus", "url": "https://doi.org/10.1093/jhered/esaf002", "author": "Genetti et al.", "datePublished": "2025", "isPartOf": { "@type": "Periodical", "name": "Journal of Heredity" }, "identifier": "doi:10.1093/jhered/esaf002" } ], "about": { "@type": "Taxon", "name": "Banana Slug", "scientificName": "Ariolimax columbianus", "description": "Slime that numbs the mouth and tongue if ingested" } }, { "@type": "FAQPage", "@id": "https://animaltracks.wiki/animals/banana-slug/#faq", "mainEntity": [ { "@type": "Question", "name": "How long do banana slugs live?", "acceptedAnswer": { "@type": "Answer", "text": "Older reports said 4 to 6 years. A study that followed a backyard population in central California found no evidence that its slugs lived more than a little over two years.", "citation": { "@type": "CreativeWork", "name": "Growth and Activity Patterns in a Backyard Population of the Banana Slug, Ariolimax columbianus", "url": "https://archive.org/download/biostor-132882/biostor-132882.pdf", "author": "Pearson, Pearson & Ralph", "datePublished": "2006", "publisher": { "@type": "Organization", "name": "The Veliger" } } } }, { "@type": "Question", "name": "What do banana slugs eat?", "acceptedAnswer": { "@type": "Answer", "text": "They are detritivores: they consume rotting plant and animal matter and feces. They also take fruit, including raspberries and blackberries.", "citation": { "@type": "CreativeWork", "name": "Banana Slug & Millipede", "url": "https://home.nps.gov/redw/learn/nature/banana-slug-and-millipede.htm", "publisher": { "@type": "Organization", "name": "National Park Service, Redwood National and State Parks" } } } }, { "@type": "Question", "name": "Are banana slugs male or female?", "acceptedAnswer": { "@type": "Answer", "text": "Both at once: a banana slug contains both sexes. Still, self-fertilization is rare.", "citation": { "@type": "CreativeWork", "name": "Banana Slug & Millipede", "url": "https://home.nps.gov/redw/learn/nature/banana-slug-and-millipede.htm", "publisher": { "@type": "Organization", "name": "National Park Service, Redwood National and State Parks" } } } } ] }, { "@type": "MusicRecording", "name": "Sycamore", "byArtist": { "@type": "MusicGroup", "name": "Caspian" }, "genre": "Post-Rock & Cinematic Orchestral", "url": "https://open.spotify.com/track/7Lp6gYzsrAvuv0qPdAJ2yA" } ] } ```