Nudibranch species, Phyllodesmium kabiranum
Photo © Teresa Zubi
Nudibranch species, Phyllodesmium crypticum
Photo © Teresa Zubi
Nudibranch species, Flabellina rubrolineata
Photo © Johanna Gawron
The radula is a rasping, protrusible, tonguelike organ found in all molluscs except bivalves and some gastropods and solenogasters. It is a ribbonlike membrane on which are mounted rows of tiny teeth that point backward. Complex muscles move the radula and its supporting cartilages (odontophore) in and out while the membrane is partly rotated over the tips of the cartilages. There may be a few or as many as 250,000 teeth, which, when protruded, can scrape, pierce, tear, or cut particles of food material, and the radula may serve as a rasping file for carrying particles in a continuous stream toward the digestive tract.
Banana slug (Ariolimax columbianus)
Photo from Lonely Planet Images
Nudibranch in eelgrass
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