Sirens Are Mermaids

"I have heard the mermaids singing, each to each."

- TS Eliot, "The Love Song of J. Alfred Prufrock"

As You Know, mermaids, like all fictional creatures, can vary in their portrayal from work to work.

However, despite all the differences in mermaid portrayals, they seem to have one thing in common. For some reason, mermaids tend to be called sirens, and are given the ability to sing phenomenally well, to the point of leading unsuspecting people to their doom.

This trope is an old one; the siren as mermaid was well-established in the medieval bestiary. In Thomas Hoccleve's early fifteenth century text, La Male Regle, lines 233 ff. speak of mermaids singing men to their deaths, as old books tell us. In more traditional definitions of mythology, the Siren is often depicted as a winged bird-woman hybrid, but somehow along the line they got confused with each other.

Compare Our Mermaids Are Different.

Anime and Manga

 * Mermaid Melody Pichi Pichi Pitch, being loosely based on The Little Mermaid, revolves around the idea of mermaids being good singers.
 * Hayame in Hell Teacher Nube is yet another mermaid with the ability to create Magic Music.
 * from Mahou Sensei Negima pactio name is Siren Valida while the outfit is more clearly mermaid themed than harpie.
 * Sailor Aluminum Seiren is named for a Siren but is clearly filled with mermaid influences, and comes from Planet Mermaid. An Overall blue color scheme, a seashell charm on her choker, her attack, Galactia Tsunami, is water based. In the amine it is just her throwing juice boxes and water bottles. Her anime civilian name, Reiko Aya, even contains a pun on Mermaid.
 * The witch Oktavia von Seckendorff from Madoka Magica is a music-themed mermaid. May be an accidental example, as there's entirely seperate symbolic reasons for the music and the mermaid-ness.

Card Games

 * Magic: The Gathering goes back and forth with this trope. On the one hand, there's the merfolk card Seasinger, which is modeled after the siren legends. On the other, they have a separate "siren" creature type as seen on Alluring Siren.

Film

 * In Disney's The Little Mermaid, Ariel has a beautiful singing voice. Most Disney heroines do, but here it's actually a plot point, since the Big Bad's price for changing her into a human is her beautiful voice. However, this is taken from the original story.
 * In the animated film Coraline, The Other Spink sings the line "I'm known as the siren of all seven seas," while dressed as a mermaid.
 * In Pirates of the Caribbean 4, mermaids also have beautiful singing voice and lure men to death. And one of the mermaids is named Syrena. Justified because it's a mostly-ignorant human who names her that; her actual name is impronouncable.
 * In the Made-For-TV-Movie Mermaids one of the mermaid sisters Venus is a Siren and is able to hypnotise men though with dancing and her eyes instead of singing. Her powers don't work if someone knows that she is a Siren.

Literature

 * The heroine of Donna Jo Napoli's Star Crossed Lovers novel Sirena is one of the actual Greek sirens... and a mermaid. Of course, even the humans of her time have gotten a lot of the facts wrong about her and her fellow myths.
 * In TS Eliot's "The Love Song of J. Alfred Prufrock".
 * In the Anita Blake series, sirens are described as super-powerful mermaids, able to control even their own kind with the power of their voices.
 * Piers Anthony's Xanth novel The Source of Magic. The Siren is a mermaid with a voice that lures all men who hear it to her.
 * In Edgar Eagar's Magic by the Lake, the children go on an adventure with a mermaid who "sings down a ship." Martha chastises her for luring men to their deaths.
 * In the Harry Potter series, sirens are a Greek race of merpeople (noted as being the inspiration for their common artistic depiction, as compared to the "less beautiful [struck out by Harry and replaced with 'ugly']" Irish and Scottish merpeople seen in the series), and all merpeople are noted to share a common love of music. In Goblet of Fire, the second task of the Triwizard Tournament requires deciphering a clue given in Mermish song.
 * In The Lion the Witch And The Wardrobe, mermen and mermaids sing at the Pevensies coronation and the singing is described as haunting and enchanting.
 * In Siren by Tricia Rayburn, the sirens don't have fins, but they need salt water to survive and can stay under water for long periods of time.
 * In Lost Voices by Sarah Porter, the main characters are basically humans turned into mermaids, but are given magical voices like the sirens, which they use to lure humans to their deaths. These mermaids/sirens are all actually reincarnated souls of human girls who died from abuse or neglect, and take vengeance on humanity for the mistreatment in their previous lives by sinking ships and drowning people.

Live Action TV

 * In H 2 O Just Add Water Cleo has a reaction to the full moon's reflection and gains a singing voice that is able to hypnotise all the boys in town. Lewis explains that "she's a Siren, just like the mermaids in mythology whose singing lured sailors to their deaths". Funnily enough that's the only episode of the show that doesn't feature the girls transforming into their mermaid forms.
 * Charmed has a notable subversion. The fifth season featured two episodes pretty close together, one dealing with a mermaid and the other dealing with a Siren. Though in this case the Siren is a demon and unconnected to the water at all.
 * The pilot for the Aquaman TV show introduced what probably would have been recurring enemies - Sirens that were basically really ugly mermaids.

Theater

 * In Shakespeare's A Midsummer Nights Dream, Oberon's story of the magic flower for the love potion includes a mermaid's beautiful singing, though she calms the sea rather than allures anyone to death.
 * The Comedy of Errors alludes to this trope with the line "I'll stop mine ears against the mermaid's song."

Video Games

 * Elulu from Luminous Arc 3 whose job class is Siren but also bears a lot of traits similar to mermaids.
 * The Sirens of Mabinogi fit this to a tee. If you need an image, you don't need to look for one, they're almost the same as the above picture from Luminous Arc (however, they are NOT a rip-off). And they're bad guys.
 * A little bit of Fridge Brilliance: The Zora (read: merfolk-like fish people) from The Legend of Zelda evolve over time into the Rito (mythological siren-like bird folk). Medli, one of the main Rito in The Wind Waker even plays a harp, though not to coerce anyone to their doom, luckily.
 * Averted in God of War, where sirens are land-dwelling (levitating) demons.
 * Defense of the Ancients includes a Siren hero whose ultimate spell is to sing the opposition to sleep and whose character model is a mermaid.
 * Averted but acknowledged in Legend of Mana. Mermaids and Sirens are different species, mermaids being fish-tailed humanoids who can teleport via bubbles and sirens being beautiful harpy-like creatures that look like a cross between birds of paradise and a women. The two species are friendly with each other, however, and implied to be distantly related in some way.
 * The Final Fantasy series averts this, with Siren being an uncommonly recurring character (often a summon) that usually just resembles a beautiful woman. Final Fantasy VIII actually has more of a bird-like appearance with feathery details including long hair styled like wings -- though its summoning sequence does feature it appearing on a rock jutting out of the sea.

Web Comic

 * In Kate Beaton's Hark a Vagrant, a mermaid aims to drown a sailor with her frilly singin'. Mermaids matching this trope make a few other appearances, including one longer story arc (where no mermaid singing is heard, but is referred to, along with their tendency to drown people).

Web Original

 * In The Dragon Wars Saga, the chief songstress of the merfolk clan encountered early on is named Sirin and the mermaids have command of some kind of vocal music.

Western Animation

 * Coincidence or not, the mermaid queen from The Marvelous Misadventures of Flapjack reincarnates into a flying version called 'skymaid', becoming more like a siren.
 * Averted in American Dragon Jake Long, both mermaids and sirens are present and are quite different from one another.

Real Life

 * This trope is so widespread that in in Spanish, French, Italian, Polish, Latin, Romanian and Portuguese the word for mermaid is respectively Sirena, Sirène, Sirena, Syrena, Syreni, Sirenă, and Sereia.
 * It's popularly held that manatees (Order Sirenia) are often mistaken for mermaids.