What do snails octopuses and mussels breathe with lungs or gills?
i know that snails have gills i am not sure about the others
Snails that live on land use a lung to breathe, fairly similar to you or I. Aquatic snails use gills to breathe, similar to fish. Terrestrial snails may produce bubbles as a result of breathing because they secrete a mucous. Air sometimes gets trapped in the mucous, which can cause bubbles to form. But it is not how they breathe.
some snails have lungs which make it so that they will need air to breath and preferably have land to travel on, but others have gills so that makes it so that they don't need any air and prefer to stay in the water at all times. keep in mind that snails do have different breathing habits just so that you don't drown them or deprive them of there water. :)