Gastric Groomers

When toads or frogs eat a bad ’un--ants and wasps can contain some nasty toxins--they take a drastic measure: they throw up their entire stomach. It’s very dramatic, says Richard Wassersug. Their stomach hangs out of the side of their mouth, and they wipe it with their hand. Wassersug, an anatomist at Dalhousie University in Nova Scotia, and a colleague, Tomio Naitoh of Shimane University in Japan, now have a unique claim to fame: they are the first to note that retching amphibians, like this bullfrog, always use their right hand to clean their exposed stomach. Why the right hand? A toad’s or frog’s stomach, like ours, lies somewhat left of center, held in place on either side by membranes. Because the membrane attached to the right side of the stomach is shorter, it pulls the stomach to the right as it is ejected. Toads and frogs can’t reach over to the right corner of their mouth with their left hand--their arms are too stubby--so they use the right. Wassersug says it’s a behavior that could save the animal’s life. If I were a toad with only one hand, he says, I’d want it to be my right.