I think I read somewhere that there was 440 something in all...but I could be wrong. It could be more or less then the 440s...
As for seeing what all you have discovered so far, I dont think there is but you can just keep buying eggs and hatching them and mutating them until you find them all too...that also works. Or you can just mate up different ones of the same species like take the pink one for example...mate up so you get pink shark, beta, ect, or go by like pink shark, silk shark, until you get them all. You see what I am getting at? The only problem with that is making sure that your gonna get what you want.