When you hear the word alligator or crocodile, the last thing to come to your mind is sensitivity. However, a Vanderbilt University study shows that alligators and crocodiles’ sense of touch is vastly more sensitive than ours. Their study is published in the journal Journal of Experimental Biology.
It is easy to look at an alligator and think that their tough skin would be nearly impervious to touch. In fact, their skin is more like armor than anything. Amazingly, they possess these pigmented spots that look like tiny domes all over their skin. These spots are called integumentary sensor organs (ISO’s). For years, these spots were a mystery. Many believed that these spots produced some sort of oil to help protect the skin. Others believed that they were sensitive to electromagnetic pulses, or possibly were sensitive to changes in water’s salinity. A 2002 study at the University of Maryland however, showed that these spots were sensitive to ripples made by water drops. This intrigued Ken Catania, Stevenson Professor of Biological Sciences at Vanderbilt, enough that he began studying the function of these ISO’s even further. Below, you can see a Vanderbilt University video featuring Duncan Leitch, a graduate student serving under Catania.
It appears that these ISO’s are linked to a nerve bundle that is very similar to the ones we humans have called trigeminal ganglia. They are so sensitive that they can detect the ripple that a drop of water produces on the surface. They can also detect pressures that even the human fingertip can’t detect. This only serves to make them even better predators. The largest concentrations of these sensors appear to be around the mouth near the teeth. The same sensors that enable their deadly accuracy also serve the mothers as they gently assist their eggs in hatching as well as, carrying their young in their mouth without crushing them to death. Never let it be said that these fearsome creatures don’t have a softer and more sensitive side.
For more information, visit Vanderbilt University’s website.