The shell of this turtle helps it survive without oxygen

The carapace first seems to be armor. In the painted turtle, she also participates in a surprising strategy to get through the winter. Work describes a survival of several months without oxygen, under cold experimental conditions close to three degrees Celsius.

The body greatly reduces its energy expenditure. But slowing down is not enough: oxygen-free operation leads to an accumulation of acidic products that must be managed. The mineral reserves of the shell and skeleton help to buffer this acidity.

What protects the animal from the outside also helps to preserve its inner balance. Performance depends on species, temperature and conditions; it does not mean that any turtle can remain underwater indefinitely. The astonishment remains intact: a structure that we regarded as a mere shield takes part in the very chemistry of survival.