Without special equipment they do not.
Hippos can't "breath" underwater but they can hold their breath for long periods of time.
How long can you hold your breath?
about a day
how does a galapagos penguin breath
I will assume you are not joking. A fish does not hold it's breath it can breathe underwater using its gills.
until they die
until they die
40 minutes
As Mario is a video game character, he can hold his breath for however long you control him underwater.
Well most people say as long as a few mins but I say test the theory you may be surprised
no, but they can stay underwater for a long time
up to 10 minutes