Wait, Carp Don’t Have What?! (Fly Fishing)

These picky fish lack an internal organ commonly found in almost 3/4 of all fish, how is that possible?

Those picky spooky fish that reject your flies, and bask in the sun just out of the reach of your cast, lack an internal organ commonly found in almost 3/4 of all fish. An otherwise important organ that should make them easier to catch… in theory.