A mermaid is a legendary aquatic creature with the head and torso of human female and the tail of a fish. The male version of a mermaid is called a merman; the gender-neutral collective noun is merfolk.
Various cultures throughout the world have similar figures. They were known to sing sailors to their deaths, like the Siren, or squeeze the life out of drowning men, while trying to rescue them.
The word mermaid is from the Middle English mere, in the obsolete sense 'sea' + maid(en). The Sirens of Greek mythology are sometimes portrayed in later folklore; in fact in some languages the name sirena is used interchangeably for both creatures.
Mermaids and their kin
Legend and myth
Tales of mermaids are nearly universal. The first known mermaid stories appeared in Assyria, ca. 1000 BCE. Atargatis, mother of Assyrian queen Semiramis, was a goddess who loved a mortal shepherd and in the process killed him. Ashamed, she jumped into a lake to take the form of a fish, but the waters would not conceal her divine nature. Thereafter, she took the form of a mermaid — human above the waist, fish below — though the earliest representations of Atargatis showed her as being a fish with a human head and legs, similar to the Babylonian Ea. The Greeks recognized Atargatis under the name Derketo, where she was often conflated with Aphrodite.
Lucian of Samosata in Syria (2nd century CE) in De Dea Syria ("Concerning the Syrian Goddess") wrote of the Syrian temples he had visited:
- "Among them - Now that is the traditional story among them concerning the temple. But other men swear that Semiramis of Babylonia, whose deeds are many in Asia, also founded this site, and not for Hera Atargatis but for her own Mother, whose name was Derketo"
- "I saw the likeness of Derketo in Phoenicia, a strange marvel. It is woman for half its length, but the other half, from thighs to feet, stretched out in a fish's tail. But the image in the Holy City is entirely a woman, and the grounds for their account are not very clear. They consider fishes to be sacred, and they never eat them; and though they eat all other fowls, they do not eat the dove, for she is holy so they believe. And these things are done, they believe, because of Derketo and Semiramis, the first because Derketo has the shape of a fish, and the other because ultimately Semiramis turned into a dove. Well, I may grant that the temple was a work of Semiramis perhaps; but that it belongs to Derketo I do not believe in any way. For among the Egyptians, some people do not eat fish, and that is not done to honor Derketo." <ref>Lucian of Samosata, De Dea Syria Part 2, Chapter 14</ref>
A popular Greek legend has Alexander the Great's sister, Thessalonike, turn into a mermaid after her death Teacher's Guide. She lived, it was said, in the Aegean and when sailors would encountered her, she would ask them only one question: "Is Alexander the king alive?" to which the correct answer would be "He lives and still rules" Any other answer would spur her into a rage, where she transformed into a Gorgon and meant doom for the ship and every sailor onboard.
Among the Neo-Taíno nations of the Caribbean the mermaid is called Aycayía  she of the beautiful voice. . Her attributes relate to the goddess Jagua, and the hibiscus flower of the majagua tree Hibiscus tiliaceous . Examples from other cultures are the Mami Wata of West Africa, the Jengu of Cameroon, the Merrow of Ireland and Scotland, the Rusulki of Russia, and the Greek Oceanids, Nereids, and Naiads. One freshwater mermaid-like creature from European folklore is Melusine, who is sometimes depicted with two fish tails, and other times with the lower body of a serpent. It is said in Japan that eating the flesh of a mermaid can grant unaging immortality. In some European legends mermaids are said to grant wishes.
It has been widely suggested that manatees or dugongs could be behind the myth of the mermaid. These large aquatic mammals are notable for the way in which they carry their young, cradled in their arms much as a human would carry a baby. It is possible that sailors seeing these unfamiliar beasts for the first time, would assume that they had in fact stumbled across some sort of humanoid species, and consequently spread their accounts of the sightings through their homelands on their return from voyages. It has even been posited that the traditional image of a mermaid with long flowing hair could be attributed to manatees breaking the ocean surface underneath patches of seaweed, and giving the unfamiliar observer the impression of having long hair. Prior to 546 B.C., the Milesian philosopher Anaximander proposed that mankind had sprung from an aquatic species of animal. For, he thought, man with his extended infancy could not have survived, originally, in the manner he does presently. This idea, based on elemental forces of mutation as opposed to evolution, does not appear to have survived Anaximander's death.
- Mermaids are one of the most famous creatures of popular culture, and are depicted regularly in literature and film. This is likely due to the influence of Hans Christian Andersen's fairytale The Little Mermaid (1836), which has been translated into many languages and adapted into various media. Andersen's portrayal has arguably become the standard, and has influenced most modern Western depictions of mermaids since it was published.
- Andersen's Little Mermaid was immortalized with a famous bronze sculpture in Copenhagen harbour, and was adapted into a Disney movie (The Little The Little Mermaid, 1989). The story has been retold in other films and television programs, and regularly features in collections of fairytales.
- For many years, the comic book superhero Superman]' had a romantic love interest with a mermaid named Lori Lemaris. The name Lori Lemaris was probably drawn from Lorelei rock in the Rhine added to maris, from the Latin mare, meaning ocean.
- In the second series of the anime version of Those Who Hunt Elves mermaids are portrayed as a group of female elves who wear fish-like suits around their lower bodies, though they have regular human legs.
- A more recent anime currently being released in the US is Mermaid Melody Pichi Pichi Pitch which follows more of the orginal little mermaid pattern. It holds the similar idea as Splash where the girls can remain onland with legs until they get wet.
- Mermaids are also fictional creatures in the Dungeons and Dragons game. They are the females of the merfolk race. The males are known as mermen.
- Mermaids as well as mermen are collectively referred to as "merfolk" in the popular trading card game Magic: the Gathering. Merfolk were an inconic creature type for blue mages for much of the game's history, until Magic R&D mysteriously stopped printing them (the last Merfolk printed as of August 2006 was Torment's Ambassador Laquatus). It has been confirmed that merfolk return in October 2006's Time Spiral expansion.
- In Rumiko Takahashi's Mermaid Saga, a legend tells that those who eat the flesh of a mermaid will become immortal. In truth, this only happens with a small number of people. The rest either die, or become horrible monsters
A Book of Mermaids, by Ruth Manning-Sanders, is a representative book of 16 fairy tales from around the world.
- Sue Monk Kidd in "The Mermaid Chair", published in 2005, invents a mermaid saint, based on an actual legend about a chair in Cornwall.
- In the novel Sirena Donna Jo Napoli offers a love tale of the Trojan war from the point of view of a mermaid, based on a character from The Iliad.
- In the novel Etefjeyyk, author Sean Bridges plans to work in an underwater city of mermen and mermaids in some way, along with other magical creatures, like djinns, sphinxes, elves, unicorns, etc.
- Mermaids are featured in the Peter Pan novel and in the adaptations of it (such as the film Hook) and the Harry Potter series, specifically in Harry Potter and the Goblet of Fire.
- L. Frank Baum (creator of Oz) wrote a novel about merfolk, The Sea Fairies.
- In Splash (1984), starring Daryl Hannah and Tom Hanks, Hannah played a mermaid who fell in love with a man. She could walk dry land as a human female, but whenever water touched her legs they changed into a fish-tail. Much of the movie revolves around her humorous attempts to conceal her true identity from her lover. A made-for-television sequel, Splash, Too
 followed in 1988. It starred Amy Yasbeck and Todd Waring, and was later made in to a short lived television series. ustralian television series, H2O: Just Add Water (2006), involves 3 teenage girls who, after encountering a mysterious island grotto, transform into mermaids whenever water touches any part of their bodies in a similar way.
- In Local Hero (1984), Marina (Jenny Seagrove) is suspected by love interest of being a mermaid, in that she: 1. can stay underwater without coming up for air far longer than humanly possible, 2. swims regularly between the town of Ferness and Aberdine without a breathing apparatus, and 3. has webbed feet. Like sailors of old, Danny follows her into the sea at the end, where she seemingly sports a mermaid fin. However, whether she is a mermaid or not is never answered.
- Miranda (1948), starring Glynis Johns, is another popular film to feature a mermaid. She Creature (2001) featured a villainous mermaid who seemed to have a taste for human flesh and lesbian tendencies.
- A made-for-cable movie, Mermaids starring Nikita Ager, Sarah Laine and Erika Heynatz aired on the PAX network in 2003. It was about a trio of mermaid sisters named Venus, June and Diana who solve their father's murder.
- A made for Disney Channel movie "The Thirteenth Year" suggests that a mermaid could be a normal human until he/she turns the age of 13.
- Aquamarine, a novel by Alice Hoffman, is about two 12 year old girls who discover a sassy teenage mermaid. The novel was popular among teen and preteen girls. The novel was made in to a film released in 2006 by Twentieth Century Fox and starred Sara Paxton, Emma Roberts and JoJo .
- The television show "Fantasy Island" had a mermaid character. One also appeared in an episode in the third season of "Voyage to the Bottom of the Sea".
- In "Power Rangers Mystic Force", the Blue Ranger turns into the Mermaid Titan. This is based upon MagiMermaid, the Majin form of Magiblue in "Mahō Sentai Magiranger".
- In the Futurama episode "The Deep South", the crew encounters Mermaids who inhabit the fabled lost city of Atlanta in the year 3000. The concept of mermaids not having the same reproductive functions as humans in the show is a reference to the mermaid problem. When Fry wishes that his mermaid lover Umbriel could've been the mermaid with "the fish part on top and the lady part on the bottom", this is a jab at an episode of Night Gallery  called "Lindermann's Catch" , about a fisherman who wants to give a mermaid he's fallen in love with legs, but his wish backfires when her fish half becomes her human half and her human half (her head) becomes the fish part.
- In 2006, NBC's soap opera Passions added a mermaid character named Siren, brought to life by the toddler witch Endora to keep her half-brother's fiance from leaving him.
- In Dave Barry and Ridley Pearson’s prequel to Peter Pan, "Peter and the Starcatchers", mermaids come into being when a female fish is exposed to starstuff.
- In heraldry, the charge of a mermaid is commonly represented with a comb and a mirror, and blazoned as a 'mermaid in her vanity.' Merfolk were used to symbolize eloquence in speech.
- A shield and sword-wielding mermaid (Syrenka) is the official Coat of Arms of Warsaw, the capital of Poland.
- Advertising characters from television commercials include the Chicken of the Sea Mermaid, the cartoon mascot for a brand of tuna.
- The Starbucks Coffee logo, is a picture of a two tailed mermaid in ever increasing close-up.
Sirenomelia, also called "mermaid syndrome", is a rare congenital disorder in which a child is born with his or her legs fused together and the genitaliareduced. This condition is about as rare as conjoined twins and is usually fatal within a day or two of birth because of kidney and bladdercomplications, though there are three known survivors of this disorder alive today.
In the 19th century, P. T. Barnum displayed in his museum a taxidermal hoax called the Feejee (sic) Mermaid. Others have perpetrated similar hoaxes, which are usually papier-mâché fabrications or parts of deceased creatures, usually monkeys and fish, stitched together for the appearance of a grotesque mermaid. In the wake of the 2004 tsunami, pictures of Fiji mermaids were passed around on the internet as something that had washed up amid the devastation, though they were no more real than Barnum's exhibit 
- Beautiful Mermaid Art Collections of mermaid art, folk tales and myths.
- Mermaids on the Web annotated directory of 400 websites and 1,250 images
- "The Mermaid" by Heinz Insu Fenkl, from the mermaid-themed Summer 2003 issue of the Journal of Mythic Arts
- The mermaid goddess Derketo from Lucian of Samosata's On the Syrian God (2c. AD)
- Coney Island Mermaid Parade mermaids on parade
- Doll Palace Mermaids Mermaids dolls and avatars in pixel-art
- Mermaid found in Malaysia
- Mermaids A variety of lovely mermaid images that are in the public domain.