I THINK IT'S A BUT I JUST WANT A SECOND OPINION. Which sentence is correct?

Of the manatees, our river guide said simply: "They are a disappearing breed."
Of the manatees, our river guide said, simply "They are a disappearing breed."
Of the manatees, our river guide said: simply "They are a disappearing breed."
Of the manatees: our river guide said simply "They are a disappearing breed."