AnimalTracks.wiki

What the sources say

Banana SlugAriolimax columbianus

Every figure, record and mechanism on the Banana Slug profile was written from a source, and this is the working table behind it: 43 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

Profile updated

Source
01

National Park Service, Redwood National and State Parks

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

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

Source
02

National Park Service, Muir Woods National Monument

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

The page sayscoated in slime that numbs the mouth and tongue if swallowed
The source saysnumbing the mouth and tongue if ingested
The page saysSlime that numbs the mouth and tongue if ingested
The source saysnumbing the mouth and tongue if ingested
The page saysOne national park page calls the mucus a defence against predators, numbing the mouth and tongue if ingested.
The source saysThis mucus also serves as a defense against predators, numbing the mouth and tongue if ingested.

Source
03

Pearson, Pearson & Ralph 2006

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

The page saysA two-year study of a backyard population in central California weighed 150 slugs, from 0.4 to 75.4 g.
The source saysOver a period of two years 150 individual Ariolimax columbianus weighing between 0.4 and 75.4 g were identifiedNote: Study site: Orinda, Contra Costa County, 'suburban area of central California' per the abstract. Weighed on an electronic balance per Methods.
The page saysthe team kept a tray stocked with lettuce, melon rind and apples.
The source saysa 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
The page saysEven so, a 107 g slug appeared on the deck in 2003, three years after the feeding ended.
The source saysin 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 foodNote: 'Even so' carries the paper's own conclusion: large size 'was not dependent on supplied food'.
The page saysIn both study years, slugs under a gram appeared in January and gained an average of 0.11 g a day.
The source saysIn 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.
The page saysWeights peaked in summer, and in autumn slugs may lose up to 50% of their top weight.
The source saysMaximal weights are reached in summer. In the following autumn months, slugs may lose up to 50% of their maximal weight.
The page saysOlder reports gave a lifespan of 4 to 6 years
The source saysIt has been stated repeatedly that Ariolimax columbianus has a life span between 4 and 6 years
The page saysbut the team found no evidence that their backyard slugs lived more than a little over two years.
The source saysOur study finds no evidence that these slugs live more than a little over two years.
The page saysOlder 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.
The source saysIt 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.
The page saysThose backyard slugs grew quickly.
The source saysA monthly analysis of the composition of the slug population by weight groups also supports a rapid weight increase
The page saysweightKg: 0.03
The source saysRichter's study, which averaged 25 to 35 g and weighed a maximum of 45 gNote: battleStats (#1152); Richter 1976 Washington population as reported by Pearson; the fed Orinda population is larger (many over 50 g)
The page saysNot Evaluated
The source says150 individual Ariolimax columbianusNote: 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).

Source
04

Verdugo et al. 1987

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

The page saysThe skin releases giant mucin granules, which burst outside the cell and, once hydrated, form the typical slug mucus.
The source saysGiant 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 page saysThe granules contain calcium, and calcium is released from a granule immediately before it bursts.
The source saysthese 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 page saysThe researchers propose that calcium shields the mucins
The source sayswe propose that calcium functions as a shielding cation of polyionic mucins
The page saysthe long-chain molecules that make up slime
The source saysThe polymer matrix of mucus is made out of long-chain glycoproteins called mucinsNote: Said of mucus in general in the same abstract.
The page sayswhose charges would otherwise stop them packing into the granule.
The source saysthe polyionic charges of mucins prevents condensation unless they (the mucins) are appropriately shielded
The page saysIts slime is packed in granules that burst outside the body
The source saysGiant 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 mucusNote: vibe.reason, same quote as the body

Source
05

Deyrup-Olsen et al. 1992

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.

The page saysIn lab tests, a trace of a chemical called ATP made newly secreted granules rupture.
The source saysNewly 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.
The page saysMechanical stress and cold did the same.
The source saysMechanical stress, exposure to cold (e.g., 1 h at 0 degree C), and pertussis toxin also cause rupture
The page saysthe slime comes pre-packed
The source sayssecretes mucus packaged in granules
The page saysa trace of ATP
The source saysNewly secreted granules rupture in the presence of ATP (approximately 1 microM).Note: vibe.reason, same quote as the body
The page saysa jolt or cold sets them off
The source saysMechanical stress, exposure to cold (e.g., 1 h at 0 degree C), and pertussis toxin also cause ruptureNote: vibe.reason, same quote as the body

Source
06

Genetti et al. 2025

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

The page saysBanana slugs as a group are the largest terrestrial slug in North America, with lengths exceeding 26 cm.
The source saysBanana 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 cmNote: Genus scope: the paper says banana slugs, Ariolimax, as a group.
The page sayswhich holds up to six species in California.
The source saysWithin California, the genus includes up to six species
The page saysThat 26 cm figure covers the whole genus
The source saysBanana 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

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.