How many different devil fish are there?

There's no such thing as a "devil fish" in the scientific sense. This term is sometimes used casually, but it doesn't refer to a specific species.

It's possible you're thinking of one of these:

* Devil rays: These are large, flat rays with horns on their heads. There are about 5 different species of devil rays.

* The common octopus: This is sometimes called a "devilfish" due to its intelligence and ability to change color.

* Other cephalopods: The term "devilfish" might be applied to other squid, cuttlefish, or octopus species depending on local usage.

It's important to be precise with scientific names to avoid confusion. If you're interested in learning about a specific creature, try specifying which type of ray, squid, or octopus you're thinking of.