How did mermaids like the one in the photo above become whatever that thing in in the photo below?
From the Museum of Hoaxes: In mid-July, 1842, an English gentleman named "Dr. J. Griffin", a member of the British Lyceum of Natural History, arrived in New York City bearing a remarkable curiosity — a real mermaid supposedly caught near the Feejee Islands in the South Pacific. The press were expecting him, since throughout the Summer they had been receiving letters from Southern correspondents describing the doctor and his mermaid. So when he checked in to his hotel, reporters were waiting for him, demanding to see the mermaid. Grudgingly he obliged. What they saw totally convinced them of the creature's authenticity.
Soon after this, the showman P.T. Barnum visited the offices of the major papers where he explained that he had been trying to convince Dr. Griffin to display the mermaid at his museum. Unfortunately, the doctor was unwilling to do so. So Barnum volunteered to give the papers use of a woodcut of a beautiful, bare-breasted mermaid that he had prepared, since it was now useless to him. The papers (each thinking they had an exclusive) happily accepted the offer, and on Sunday, July 17, mermaid woodcuts appeared in all the papers. Simultaneously, Barnum distributed ten thousand copies of a pamphlet about mermaids throughout the city. The mermaids in the pamphlet were also represented as seductive ocean maidens.
With all this publicity, anticipation to see the Feejee Mermaid (as it was now being called) became enormous. (Note: it's also often spelled Fiji or Fejee.) It was the main topic of conversation throughout the city. Everyone was talking about whether it was a real mermaid. They had to see it for themselves. So Dr. Griffin agreed to exhibit it for a week at Concert Hall on Broadway.
Read the full story here.