Recently we heard news that Stephen Graham and either Max Irons or Sam Claflin were joining the cast of Pirates of the Caribbean 4. Now we're hearing word of another new casting addition. Read on for all the details.

According to an official press release from Walt Disney, French actress Astrid Berges-Frisbey has joined Pirates of the Caribbean: On Stranger Tides as a "beautiful and alluring mermaid," with the role being described as "key."

If I'd heard this casting news from another source (i.e. not an official press release from the studio) then I might have thought the role to be relatively minor in the overall scheme of things. But the official announcement suggests she really will be an important part of the story.

So who is this actress? Well, she's not been in much - just a few French films and TV shows to her name - but something tells me she was chosen for more than just her acting skills. The words "beautiful and alluring" are certainly applicable :P .

What's probably more interesting than who is playing the mermaid is the fact the Pirates franchise has evidently expanded and is bringing in more fantastic creatures and myths. I'm definitely interested to see how a mermaid fits into the announced plot of Captain Jack searching for the Fountain of Youth. Will Syrena the mermaid be a help or a hindrance to his quest?

In case you want to know more, you can check out an excerpt from the the official press release from Disney below:

Astrid Bergès-Frisbey has been selected by producer Jerry Bruckheimer and director Rob Marshall to star in the key role of Syrena, a beautiful and alluring young mermaid, in Walt Disney Pictures’/Jerry Bruckheimer Films’ epic adventure “Pirates of the Caribbean: On Stranger Tides,” the fourth in the blockbuster series of films. Bergès -Frisbey joins Johnny Depp, returning in his iconic role of Captain Jack Sparrow. The film is slated to open on May 20, 2011.

Born in Barcelona of French-American and Catalan parentage, and now based in Paris, Bergès-Frisbey, one of France’s brightest young stars, appears in such French films as “La Fille du Puisatier,” “Bruc,” “Extase,” “La Premiere Etoile” and “Un Barrage Contre le Pacifique.” She has also appeared in the telefilms “La Reine Morte,” “Elles et Moi,” “Divine Emilie” and “Sur le Fil.” Berges-Frisbey appeared on stage at the Theatre Marigny in a production of Peter Shaffer’s “Equus.”

What do you think of Pirates of the Caribbean 4 adding a mermaid to the story? What do you think of the actress cast in the role?

Pirates of the Caribbean 4: On Stranger Tides starts filming in June (in places like Hawaii, the UK and Los Angeles) and has a release date of May 20th, 2011

Source: Disney