Home
http://news.nationalgeographic.com/news/2012/10/121012-turtles-urine-pee-mouth-science-animals-weird?source=sailthru
When a species of soft-shelled turtle in China piddles in puddles, it does so through its mouth—the first evidence of an animal doing so, a new study says.
The findings could also have stomach-churning implications for humans with kidney failure, scientists say.
Researchers at the National University of Singapore noticed Pelodiscus sinensis turtles would stick their heads into puddles of water and wiggle their tongues, but they weren't drinking.
Study leader Yuen K. Ip and colleagues also knew that the soft-shelled turtle had structures similar to gills inside its mouth, which had previously been thought to help the turtle breathe—but did not actually function as gills.
"However, I saw a controversy here," Ip said via e-mail. "If the turtle has lungs, why would it need to submerge its head in water [to breathe]?"
To find out, the researchers purchased live turtles from a local market and kept them in water for six days. Only 6 percent of the urea—the main ingredient in animal urine besides water—produced by the turtles ended up in the urine from their hind ends.
After the researchers removed the reptiles from the water but provided them with a puddle, the turtles dipped their heads and, using the water puddles as a mouth rinse, spat out 50 times more urea than was present in the mouth discharge. The urea travels through the reptiles' bloodstreams to their mouths, so it's not technically urination.
The team also found that the turtles carry a gene that produces a specialized protein that helps expel urea. The gene was expressed in their mouths, not their kidneys.
I see a medicine on the horizon here.
When a species of soft-shelled turtle in China piddles in puddles, it does so through its mouth—the first evidence of an animal doing so, a new study says.
The findings could also have stomach-churning implications for humans with kidney failure, scientists say.
Researchers at the National University of Singapore noticed Pelodiscus sinensis turtles would stick their heads into puddles of water and wiggle their tongues, but they weren't drinking.
Study leader Yuen K. Ip and colleagues also knew that the soft-shelled turtle had structures similar to gills inside its mouth, which had previously been thought to help the turtle breathe—but did not actually function as gills.
"However, I saw a controversy here," Ip said via e-mail. "If the turtle has lungs, why would it need to submerge its head in water [to breathe]?"
To find out, the researchers purchased live turtles from a local market and kept them in water for six days. Only 6 percent of the urea—the main ingredient in animal urine besides water—produced by the turtles ended up in the urine from their hind ends.
After the researchers removed the reptiles from the water but provided them with a puddle, the turtles dipped their heads and, using the water puddles as a mouth rinse, spat out 50 times more urea than was present in the mouth discharge. The urea travels through the reptiles' bloodstreams to their mouths, so it's not technically urination.
The team also found that the turtles carry a gene that produces a specialized protein that helps expel urea. The gene was expressed in their mouths, not their kidneys.
I see a medicine on the horizon here.
