Did you know the turtle that can breathe through its butt? Again I learned something interesting at vsauce – this episode about farts.
When you hold in your farts they will (or rather, the gases will) be absorbed and some of the oxygen will be taken by your blood back to your lungs. Way to go with breathing!
So, the Fitzroy River turtle took it to the next level, taking water in and out of its butt, absorbing some of the oxygen, thus being able to stay longer under water.