National Geographic
Menu

Ode to the Banana Slug

Every year at BioBlitz, National Geographic and the U.S. National Park Service rally to get people young and old to explore the wild spaces around them during a whirlwind 24-hour search to identify every species they can find. In advance of our next event in Golden Gate National Recreation Area, March 28-29, 2014, we’re already exploring stories of the life and lands of northern California. Learn More and Sign Up for BioBlitz 2014!

In this installment, National Geographic’s Caryl Sue, a California native, takes a poetic look at the banana slug (Ariolimax).

Listen, oh blitzers, to hear a story
Of a mollusk deserving of fame and glory
From Alaska to L.A. you’ll find this mug
I speak, of course, of the banana slug

Photo of a mosquito.

Photograph courtesy National Park Service, Sitka National Historic Park

At half-a-foot per minute, they’re not the fastest
In fact, they’re slower (and less sweet) than molasses
They’re also not glamorous, like their nudibranch kin
They’re yellow, and brown, like banana skins

Like most gastropods, they have “eyestalks” to see
And the tentacles below help sense chemistry
These sensory organs are required headgear
See, banana slugs have no ears to hear

With a sharp keel on top and a fringe “skirt” beneath
A mantle up front and a mouthful of teeth
They can breathe through their skin (cutaneous gas exchange)
Or through their one lung (pneumostome, not so strange)

They’re pretty large slugs (the biggest’s in Europe)
They slide around on mucus (a slime they develop)
They’re hermaphrodites, no trouble with dates
And when it’s too dry, they just aestivate

Snakes eat banana slugs, some campers try it
and Yuroks considered them part of their diet
Their bright yellow color and irreverency
Helped make them the mascot of my second-favorite UC

The most wonderful aspects of Ariolimax
Are their awesome and mind-blowing forest-floor impacts
They’re slow, not lethargic, they’re not any dozers
They’re busy detritivores, a.k.a decomposers

They gobble up detritus—that’s decaying goop
Like leaves, and mushrooms, and animal poop
On 40 times their weight in detritus, they dine
Leaving a sticky trail of mucus behind

Banana slugs help make a strong forest floor
Humus with nitrogen—nutrients galore
Redwoods depend on this one-footed wonder
So don’t just look up, be sure to look under

Learn More and Sign Up for BioBlitz 2014