美国科学60秒 SSS 2012-10-16
时间:2013-06-19 08:29:43
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(单词翻译)
Pet turtles can be unsanitary. But Chinese soft-shelled turtles really up the ante on distasteful behavior. They perform a variation on urination—through their mouths.
Most land-based vertebrates produce urine to get rid of water-soluble
toxic1 waste,
notably2 nitrogen-containing urea. But researchers found that Chinese soft-shelled turtles get rid of just six percent of their urea through the kidneys. They also discovered a high concentration of urea in the turtles'
saliva3. Which led them to one place: the mouth.
Fish can remove waste through their gills, and these air-breathing turtles have gill-like structures in their mouths. Further research showed that they also have a urea-transporting protein that helps them get rid of it. The findings are in the Journal of Experimental Biology.
When the turtles aren't able to go for long swims, they were seen spending well over an hour with their heads submerged in
puddles4.
Apparently5 they were releasing the urea and cleaning out their mouths. And maybe just looking for a little privacy.
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