Radula Action

Imagine that your teeth grew out of your tongue… and that five new rows of teeth rolled forward from the back of your mouth every 24 hours to replace the ones worn down by an instinctually compulsive licking of rocks and shells and sand. Wow… so many odd little things about human society would be radically altered if we all possessed a radula instead of our current disassociated tongue/teeth combo, don’t you think?  (Sci-fi writers take note!)

Radula1 Tonicella lineata’s radula

As the naturalist lingo of my past habitually referenced the radula as the “drill” responsible for all those tidy holes puncturing the apex of dead clam shells on Seattle’s beaches—the neat consumptive pattern left by an avaricious Moon Snail (Polinices lewisii)—my mind’s eye had always endowed radulas with a made-up morphology akin to a sandpaper corkscrew rotating from side to side. The fact, however, that the radula is actually so exotically similar (as oxymoronic as this observation might be) to our own lapping buccal appendage was therefore a bit of a conceptual adjustment.     

Radula2“Encyclopedia of nature”, Munich, 2000

Molluscs—with the exception of bivalves & aplacophorans—go around licking the world with chiton-plated tongues. Even ye olde cephalopods could potentially lick their beaks in chiton-grinding anticipation whenever a tasty morsel swims their way. And, to make it even more interesting, many of the molluscs out there also go about this feeding behavior with a noted “buccal rhythm” (see the Nobel Institute for Neurophysiology for more info on this).

Now… the sea urchins’ Aristotle’s Lantern is a pretty darn cool feeding appendage, but—at least in the anthropomorphized beat-boxing showdown between Molluscs and Echinoderms currently going on in my imagination—the radula-rhythm’d molluscs have indubitably won the “cool” award for today.   

Check out this YouTube video of “Hot Radula Action”  from this subtropical freshwater Apple Snail

P.S.   In response to Taylor’s blog post, I just wanted to share a few links I found after our lab of previously documented dissections and other virtual dissection tools.  While I believe dissection does have a very important role to play in biological training and research, I’m glad that we as a scientific and academic community are finding more and more ways to extend the utility of  each of the AWESOME organisms sacrificed so that we can better appreciate and utilize their form, function and innate biological magic to make the world a better place.

I would love to know if anyone else finds any others they think are useful!





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