---
title: "What the sources say about the Banana Slug | AnimalTracks.wiki"
description: "43 claims from the Banana Slug profile, each beside the words of the source that backs it."
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# What the sources say about the Banana Slug (*Ariolimax columbianus*)

> 43 claims from the Banana Slug profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Banana Slug](https://animaltracks.wiki/animals/banana-slug/)

## Banana Slug & Millipede. National Park Service, Redwood National and State Parks.

https://home.nps.gov/redw/learn/nature/banana-slug-and-millipede.htm

| The page says | The source says |
| :--- | :--- |
| A forest slug that may grow 20 cm long or more | it may grow to 7 inches (20 cm) long or greater |
| Coastal rainforests from southeast Alaska to central California | They occur in coastal rainforests from southeast Alaska to central California |
| Detritus (decomposing plant and animal parts and feces), plus fruit such as raspberries and blackberries | they consume detritus (decomposing plant and animal parts as well as feces) |
| plus fruit such as raspberries and blackberries | frugivore, or fruit-eater, and may play a role in seed dispersal of plants it consumes directly including raspberries and blackberries (note: 'may' in the quote hedges seed dispersal; the quote states the slug consumes these plants directly.) |
| The Pacific banana slug lives in coastal rainforests from southeast Alaska to central California. | They occur in coastal rainforests from southeast Alaska to central California |
| It may grow to 7 inches (20 cm) long or greater. | it may grow to 7 inches (20 cm) long or greater |
| Some are bright yellow like a banana, while others are greenish or brown. | Some banana slugs are bright yellow like their namesake, others are greenish or brown |
| Banana slugs eat detritus, which means decomposing plant and animal parts as well as feces. | they consume detritus (decomposing plant and animal parts as well as feces) (note: 'which means' glosses the source's own parenthesis.) |
| They also eat fruit, including raspberries and blackberries, and may help spread seeds. | frugivore, or fruit-eater, and may play a role in seed dispersal of plants it consumes directly including raspberries and blackberries |
| Five slugs per square meter are not uncommon. | 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. | Raccoons, garter snakes, waterfowl, and salamanders are known to prey on banana slugs; juveniles are sometimes eaten by shrews or moles. |
| Each slug is a hermaphrodite, carrying both sexes in one body. But they rarely fertilize themselves. | Banana slugs, like most other slugs, are hermaphrodites, meaning they contain both sexes within the individual, however, they rarely “self-fertilize”. |
| They are detritivores: they consume rotting plant and animal matter and feces. They also take fruit, including raspberries and blackberries. | Both are detritivores, or decomposers; they consume detritus (decomposing plant and animal parts as well as feces) |
| They also take fruit, including raspberries and blackberries. | may play a role in seed dispersal of plants it consumes directly including raspberries and blackberries (note: 'may' hedges seed dispersal only; the slug 'consumes directly' these plants.) |
| Both at once: a banana slug contains both sexes. Still, self-fertilization is rare. | Banana slugs, like most other slugs, are hermaphrodites, meaning they contain both sexes within the individual, however, they rarely “self-fertilize” |

## Banana Slug. National Park Service, Muir Woods National Monument.

https://www.nps.gov/muwo/learn/nature/banana-slug.htm

| The page says | The source says |
| :--- | :--- |
| coated in slime that numbs the mouth and tongue if swallowed | numbing the mouth and tongue if ingested |
| Slime that numbs the mouth and tongue if ingested | numbing the mouth and tongue if ingested |
| One national park page calls the mucus a defence against predators, numbing the mouth and tongue if ingested. | This mucus also serves as a defense against predators, numbing the mouth and tongue if ingested. |

## Pearson, Pearson & Ralph (2006). Growth and Activity Patterns in a Backyard Population of the Banana Slug, Ariolimax columbianus. The Veliger.

https://archive.org/download/biostor-132882/biostor-132882.pdf

| The page says | The source says |
| :--- | :--- |
| A two-year study of a backyard population in central California weighed 150 slugs, from 0.4 to 75.4 g. | Over a period of two years 150 individual Ariolimax columbianus weighing between 0.4 and 75.4 g were identified (note: Study site: Orinda, Contra Costa County, 'suburban area of central California' per the abstract. Weighed on an electronic balance per Methods.) |
| the team kept a tray stocked with lettuce, melon rind and apples. | a 27 X 35 cm aluminum tray, which, when we were in residence, was continuously supplied with lettuce, melon rind, cucumber, zucchini, apples, and occasional other food items |
| Even so, a 107 g slug appeared on the deck in 2003, three years after the feeding ended. | in July 2003. three years after our supplemental feeding ended, an unidentified slug weighing 107 g appeared on the deck, demonstrating that large size in the local populations was not dependent on supplied food (note: 'Even so' carries the paper's own conclusion: large size 'was not dependent on supplied food'.) |
| In both study years, slugs under a gram appeared in January and gained an average of 0.11 g a day. | In both 1999 and 2000, slugs weighing less than a gram appeared in January and, feeding both day and night, gained weight at an average rate of 0.11 g/day. |
| Weights peaked in summer, and in autumn slugs may lose up to 50% of their top weight. | Maximal weights are reached in summer. In the following autumn months, slugs may lose up to 50% of their maximal weight. |
| Older reports gave a lifespan of 4 to 6 years | It has been stated repeatedly that Ariolimax columbianus has a life span between 4 and 6 years |
| but the team found no evidence that their backyard slugs lived more than a little over two years. | Our study finds no evidence that these slugs live more than a little over two years. |
| 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. | It has been stated repeatedly that Ariolimax columbianus has a life span between 4 and 6 years (Gordon, 1995; Richter, 1976; Rollo et al, 1983; and others). Our study finds no evidence that these slugs live more than a little over two years. |
| Those backyard slugs grew quickly. | A monthly analysis of the composition of the slug population by weight groups also supports a rapid weight increase |
| weightKg: 0.03 | Richter's study, which averaged 25 to 35 g and weighed a maximum of 45 g (note: battleStats (#1152); Richter 1976 Washington population as reported by Pearson; the fed Orinda population is larger (many over 50 g)) |
| Not Evaluated | 150 individual Ariolimax columbianus (note: stats.conservationStatus. Anchors the species name only; the body makes no status claim. GBIF's copy of the IUCN Red List returns category NOT_EVALUATED for Ariolimax columbianus (A.Gould, 1851) (api.gbif.org/v1/species/2294090/iucnRedListCategory, fetched 2026-10-11); an API endpoint can't be cited, and no page found states it, so no IUCN reference is cited (#1227).) |

## Verdugo et al. (1987). Molecular Mechanism of Mucin Secretion: I. The Role of Intragranular Charge Shielding. Journal of Dental Research.

https://doi.org/10.1177/00220345870660022001

| The page says | The source says |
| :--- | :--- |
| The skin releases giant mucin granules, which burst outside the cell and, once hydrated, form the typical slug mucus. | Giant mucin granules of the slug (Ariolimax columbianus) are released intact from mucus-secreting cells of the slug's skin. They burst spontaneously outside the cell, forming, upon hydration, the typical slug mucus |
| The granules contain calcium, and calcium is released from a granule immediately before it bursts. | these granules contain from 2.5 to 3.6 moles calcium/kg dry material, and that calcium is released from the granules immediately before the burst |
| The researchers propose that calcium shields the mucins | we propose that calcium functions as a shielding cation of polyionic mucins |
| the long-chain molecules that make up slime | The polymer matrix of mucus is made out of long-chain glycoproteins called mucins (note: Said of mucus in general in the same abstract.) |
| whose charges would otherwise stop them packing into the granule. | the polyionic charges of mucins prevents condensation unless they (the mucins) are appropriately shielded |
| Its slime is packed in granules that burst outside the body | Giant mucin granules of the slug (Ariolimax columbianus) are released intact from mucus-secreting cells of the slug's skin. They burst spontaneously outside the cell, forming, upon hydration, the typical slug mucus (note: vibe.reason, same quote as the body) |

## 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.

https://doi.org/10.1152/ajpcell.1992.262.3.c760

| The page says | The source says |
| :--- | :--- |
| In lab tests, a trace of a chemical called ATP made newly secreted granules rupture. | Newly secreted granules rupture in the presence of ATP (approximately 1 microM). (note: 'a trace' for approximately 1 microM; the abstract describes in vitro granule experiments.) |
| Mechanical stress and cold did the same. | Mechanical stress, exposure to cold (e.g., 1 h at 0 degree C), and pertussis toxin also cause rupture |
| the slime comes pre-packed | secretes mucus packaged in granules |
| a trace of ATP | Newly secreted granules rupture in the presence of ATP (approximately 1 microM). (note: vibe.reason, same quote as the body) |
| a jolt or cold sets them off | Mechanical stress, exposure to cold (e.g., 1 h at 0 degree C), and pertussis toxin also cause rupture (note: vibe.reason, same quote as the body) |

## Genetti et al. (2025). Secrets of the Goo: The genome assembly of the Pacific banana slug, Ariolimax columbianus. Journal of Heredity.

https://doi.org/10.1093/jhered/esaf002

| The page says | The source says |
| :--- | :--- |
| Banana slugs as a group are the largest terrestrial slug in North America, with lengths exceeding 26 cm. | Banana slugs, Ariolimax , are found across the coastal foothills and mountains of Western North America from Southern California to Alaska. These hermaphroditic molluscs are synonymous with coastal redwood forests, but range broadly across wet forest habitats. They are the largest terrestrial slug in North America, with lengths exceeding 26 cm (note: Genus scope: the paper says banana slugs, Ariolimax, as a group.) |
| which holds up to six species in California. | Within California, the genus includes up to six species |
| That 26 cm figure covers the whole genus | Banana slugs, Ariolimax , are found across the coastal foothills and mountains of Western North America from Southern California to Alaska. These hermaphroditic molluscs are synonymous with coastal redwood forests, but range broadly across wet forest habitats. They are the largest terrestrial slug in North America, with lengths exceeding 26 cm |