Tortoises are actually not able to swim. They belong to the taxonomic order called chelonia. This order includes tortoises, turtles and terrapins. All three are cold-blooded, have scales and reproduce by laying eggs. Only two of these species, turtles and terrapins, are able to swim. Tortoises may enjoy wading in very shallow water, but they do not have limbs or bodies built for swimming.
Tortoises live on land and are herbivores, eating grasses or very short shrubs. Pet tortoises are usually fed with a diet of lettuce, alfalfa, clover and possibly some fruit. Tortoises can live as long or longer than a human, with recorded tortoise life spans of up to 176 years. Their hard shells have a high, rounded dome, and they have legs that are columnar in shape like an elephant's. Their round, stubby feet allow them to dig shallow burrows in the ground in which they can lay eggs or cool themselves in warmer weather. Tortoises do enter water to drink or to bathe, but they cannot swim and will drown if put into deep water. For smaller pet tortoises, it's important to provide a habitat that includes water for drinking and bathing, but not water that is not so deep that the tortoise can't stand. Young children should be supervised around tortoises to make sure they do not put them in a bathtub, toilet, or sink to see if they can swim.
Their lungs.
Gills.............
The organ responsible for breathing is your lungs.
lungs
This is from wikipedia:Hibernation is a state of inactivity and metabolic depression in animal, characterized by lower body temperature, slower breathing, and lower metabolic rate.slower breathing, so yes your tortoise does respire when it hibernates
Just like humans, squirrels contain lungs, the major breathing organ in the respiratory system.
Organ
lungs
nose
yes
lungs
Gills