What we found is that they cannot breathe underwater. They can just hold their breath for a long time.
Yellow-bellied sliders can stay underwater for seemingly extended periods and will sleep underwater for 30 to 40 minutes at a time, longer if the water is cool and their metabolism has slowed.
They feed while submerged and find their food by sight, scent and perhaps, by touch.
When they are ready, yellow-bellies will return to the surface to bask once again and repeat the cycle numerous times throughout the day.
When basking, the turtle extends its neck to the fullest, sticks its rear feet straight backwards and separates the toes to expose as much of the inter-digital webbing as possible. Although the forefeet also are extended, the claws often are fully in contact with the basking surface, ready to propel the turtle into the water when necessary.
Keeping a turtle? Here are some tips all new turtlekeepers need to know shared by Reptilesmagazine.com.