It is hard to imagine how the Galapagos tortoise breathes, since they have their shells surrounding their belly and back. Because of that they don't breathe like other reptiles, but in fact they are not that much different than us. The only major difference is the volume of carbon dioxide a turtle can hold in its blood. Whenever homo sapiens hold their breaths, the carbon dioxide urges us to breath again. Tortoises on the other hand, have a much higher tolerance rate. This allows them to breathe not as constantly, allowing them to inhale less frequently. One example of this is when a turtle goes into their shell, they release everything in their lungs, which for the Galapagos tortoise is a lot of gas since they are very large animals. (Basic tortoise anatomy biology) Because of this, the Galapagos tortoises have the ability to swim long distances. This and also the fact that they have necks which can extend above the water while floating. Female tortoises can store sperm for a few years. (Pearse and Avuse)