I observed this pair of mating Common Snapping Turtle in the shallow water of Lemmon Lake in the Great Trinity Forest.
The pair was observed bobbing up and down in the water, often with only the top of the male’s carapace exposed above water.
On occasion the bobbing would cease, and the female would raise her head out of the water for a quick breath of air.
But, soon she would be forced under the water again by the male’s advances.
That’s the male’s tail sticking up out of the water on the left side of the picture.
Other times the male was observed apparently spitting a stream of water from his mouth. I am not sure how to explain this behavior.