They're mostly cured with salt, but I expect the fish themselves aren't particularly salty (at least the (delcious!) Spanish marinated ones aren't salty)
The fish fried is delicious, oily, full of protein and a little salty. Salt is added routinely to the dish.
Anchovies in Spanish mean normally only the canned, very salty, thing. If you want to buy the fresh fish, there is a different word for it. The third option to consume it is marinated on vinegar, that also uses the fish name (plus "on vinegar").
I've had fresh ones grilled in Greece couple of times and they were very salty (not typical can-level but still a ton). It could be possible they add salt that much just for this fish and every other fish they prepare with normal amount of salt, but I find it unlikely.
