Salt loving creatures (prokaryotes only, really) that live in environments as extreme as the dead sea
where it is 1Molar salt. If you are not impressed by this, you should be as these poor things have to actively pump out ions from their cells
. An important halophile is the purple acid patch bacteria that have a light / rhodopsin
ion pump. This was used extensively in experiments to find out how membrane ion transport works.
See : extremophile