April 25, 2003
From: Laura Ruiz
How many noses, if any, does a slug have
The simple answer is that sea slugs don't have noses but that doesn't tell you much. We use out nose for breathing and smelling things. Perhaps you want to know what they use instead of a nose? Since they live in the sea, sea slugs get the oxygen they need by extracting it from the water. For this they use their gills, or in some cases their skin is also thin enough for oxygen molecules to pass through so it also acts as a gill. We use out nose to send air to our lungs for breathing. Our lungs have very thin ducts and folds which remove oxygen from the air in the very same way as a slugs gills. So I guess for breathing you could say the slug's gills replace the nose.
The other main function of our nose is for smelling. Many slugs, have a pair of head tentacles called rhinophores which smell things in the water. Have a look at the rhinophore page for more information. Have a look at the Nudibranch Head Page for some more information on slug sense organs.