THE ANIMAL FILES

Pacific banana slug

Ariolimax columbianus

A banana slug need not be yellow.

Pacific banana slugs range from bright yellow to darker or paler colours, sometimes with irregular black spots. Their breathing opening sits beside the mantle. Feeding and movement respond to weather, and some swallowed seeds can remain viable after passing through the animal.[1]

Follow the evidence ↓
Pacific banana slug
Image: Thomas Schoch · Commons · CC BY-SA 2.5
A side opening
The pneumostome lies on the right of the mantle.[1][2]
Weather and foraging
Harsh conditions reduce feeding activity.[1]
Seeds on a slow journey
Some ingested seeds remain viable.[1]

A side opening

A fleshy mantle lies near the head, with the breathing hole on its right. Grooves run along the body above the foot, and a mucus-secreting pit occurs near the tail tip. These are parts of a soft-bodied gastropod rather than an insect.[1][2]

Weather and foraging

Fruit from several forest plants is eaten. Drought, heavy rain and temperature extremes can reduce foraging, while suitable moist refuges become important during hot periods. Weather changes where effort is directed, from searching for food to finding a tolerable resting place.[1]

Seeds on a slow journey

Studies found that many seeds remained viable after ingestion and redistribution. Slugs can also move seeds from other animals' faeces. Their contribution to dispersal is limited by short travel distances, so seed passage should not become a claim of guaranteed long-distance forest renewal.[1]

A COMMON MIX-UP

Does every banana slug have a bright yellow body?

No. Colour and black spotting vary substantially.[1]

TRY A LITTLE REASONING

Why does a viable seed in slug faeces not establish long-distance dispersal?

Reveal the explanation

Viability and distance are different measurements, and these slugs usually move relatively short distances.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Pacific banana slug (cited revision)
  2. NCBI Taxonomy — Ariolimax columbianus

Last fact check:

One discovery leads to another

Roman snailThe shell has a doorway—and sometimes a temporary seal.Helix pomatia ↗Blue sea dragonThe blue side facing the sky is actually the sea slug’s underside.Glaucus atlanticus ↗Common periwinkleA snail on a rock may be grazing a film you can barely see.Littorina littorea ↗