Do devil fish live in salt water?

"Devil fish" is not a scientifically recognized term. However, it's likely you're referring to either:

* Devil rays: These large rays are indeed found in saltwater, primarily in warm tropical and subtropical oceans.

* Octopus: Sometimes referred to as "devilfish" due to their intelligence and sometimes intimidating appearance, octopuses also live exclusively in saltwater environments.

So, to answer your question directly, yes, the animals most likely referred to as "devil fish" live in saltwater.