Comments: Not to be pedantic, but mermaids -- supposedly half-fish, half-human creatures who live in the sea and lure enamored sailors to their death -- are a staple of myth and legend going back thousands of years. They don't exist.
On the other hand, there is a related tradition of slightly more recent origin, perhaps dating back 1,500 years, which consists of manufacturing fake mermaid carcasses for public display out of the body parts of dead monkeys and fish. The photographs you have just seen exemplify such a hoax.
Another specimen still in existence was fabricated in Japan and said to be 1,400 years old. Yet another, and certainly the most famous, is P.T. Barnum's Feejee Mermaid, an artifact purchased secondhand by the great showman in the mid-1800s and exhibited throughout the United States as a sideshow attraction. There is an uncanny similarity between all of these examples.
The glaring irony in all this mermaid fakery, however, is that the mummified specimens typically displayed are, without exception, hideous in appearance - "the incarnation of ugliness," as one American critic described Barnum's creature - while the classic mermaid of folklore and popular culture is invariably depicted as beautiful and alluring. It's a discrepancy no one ever bothers to explain.
Update: These same images circulated again in early 2005 in an email claiming the carcass was found washed up on a beach in Chennai, India in the wake of the Indian Ocean tsunami of December 26, 2004.