DAKAR, Senegal — After Disney cast a black actress to play the next Little Mermaid and #NotMyAriel started trending on Twitter, the Senegalese painter Kiné Aw thought of her muse: a dark-skinned woman — a goddess, really — with seductive eyes and a fish tail.

Unlike Ariel or Disney or even the original Danish story, the West African legend Mami Wata has existed for six centuries. Some call her a mermaid. Others label her a water spirit, an aquatic being who sinks ships, changes shape and spreads fertility like gossip.

Mami Wata most often appears in folklore with flowing hair and snakes around her neck. She can sprout legs and strut into nightclubs. She is feared and admired. She is old yet modern.

So why can’t she inspire a cartoon?

“I never perceived Ariel as a white person,” said Aw, 41, standing among her portraits of fish women at a Dakar studio. “I saw her as a mermaid.”

Disney’s announcement this month that singer Halle Bailey won the starring role for its live-action remake of the 1989 film marked the first time the studio has hired a woman of color to play one of its originally white princesses. 

The decision sparked praise — “Halles get it DONE,” actress Halle Berry posted — but some Twitter users slammed the casting, asserting that Ariel should resemble the animated version with Danish roots:

“No. Ariel is a white redhead . . . Boycotting this disgrace. #notmyariel,” read one tweet.

“RESIGN!!!” another user virtually shouted. “All generations raised with WHITE Ariel with Red hair!!! Leave classic Disney movies in peace!”

“I’m not going to see this movie, I really think you are beautiful but I want to see the same Ariel as the original movie, this is my favorite movie, I’m sorry but NO,” another commented.

The Disney-owned cable network Freeform responded to the critics in a Sunday statement.

“Danish mermaids can be black because Danish *people* can be black,” the channel wrote on Instagram, noting that the character of Ariel is a “work of fiction.”

Mermaids, of course, don’t belong to one region. The earliest fish-women emerged in southwestern Asia’s ancient Mesopotamia, said Sarah Peverley, a cultural historian at the University of Liverpool in England.

“But almost every culture has a version of a mermaid,” she said. “They come in all shapes, sizes and skin color.”

When the Danish author Hans Christian Andersen published “The Little Mermaid” in 1837, people across Africa were already swapping tales about Mami Wata.

Shrines to the ocean deity line the historic slave coast of western Africa, from Senegal to Ghana to Angola, said Andrew Apter, interim director of the James S. Coleman African Studies Center at UCLA. Historians speculate that figureheads on the bows of trade ships might have influenced her image.

“She represents a fusion of the European sailors’ spirit world and West African spirit worlds,” Apter said.

People still paint Mami Wata’s face, carve her tail from bronze and write songs about her amorous power. 

Nigerian rapper Paybac proclaims he wants to “drown inside your love” in the track “Mami Wata,” and Beyoncé paid tribute to the mermaid at her 2017 Grammy performance with a gold string bikini.

“All these people just discovering mami wata because of a Disney movie announcement, lol. do better,” Ni­ger­ian American fantasy writer Nnedi Okorafor tweeted this week.

“Her reputation is edgy, shadowy, to some it’s evil,” Okorafor added in an email to The Washington Post. “There’s nothing Disney-esque about Mami Wata.”

In Dakar, Senegal’s capital and the westernmost point of Africa, artists sell renderings of the mermaid for thousands of dollars.

Mballo Kebe, 72, can sketch Mami Wata in minutes. He pulls out a notepad on a recent afternoon and draws her with snakes adorning her shoulders and waist. 

Disney’s Ariel had to choose between her voice and the ability to survive on land. Kebe crafts his water goddess with legs. She can walk and talk whenever she wants — and wreak deadly havoc.

“If there is a tsunami, people will say, ‘Mami Wata isn’t happy,’ ” said Kebe, working with a blue pen. “That’s why it took place.”

In Aw’s studio, a three-foot portrait of Mami Wata hangs on the beige wall. Another is propped on an easel. The mermaids have scaly tails and intense stares. They go for the equivalent of about $4,270.

“She’s strong,” the painter said, gesturing toward her pieces. “She’s elegant. She’s captivating.”

One frame shows Mami Wata clutching a red human heart — a nod to her grip on the imagination.