The Seven Princesses of Atlantica (commonly referred to as the Daughters of Triton) are the daughters of King Triton and Queen Athena, debuting in the 1989 Disney animated feature film, The Little Mermaid.
Attina, Alana, Adella, Aquata, Arista, and Andrina first appear in the original film, introduced during the "Daughters of Triton" sequence. They perform in the concert that Sebastian is putting on that will be the musical debut of their youngest sister, Ariel. However, much to their shock and embarrassment, Ariel fails to show up, resulting in the concert being ruined. Later, in the film, they are the first to notice Ariel's unusual happy behavior, with all of them quickly realizing that their younger sister has fallen in love (unaware at the time that she has fallen in love with a human named Eric) believing that the person Ariel has fallen in love with is a merman. At the end of the film, they are last seen attending Ariel and Eric's wedding as Andrina and Aquata wave goodbye to Ariel.
The Little Mermaid (TV series)
Just like in the original film, Attina, Alana, Adella, Aquata, Arista, and Andrina have minor roles in the prequel series, however, in some episodes, Alana and Arista respectively are supporting characters.
The Little Mermaid II: Return to the Sea
Attina, Andrina, Aquata, and Adella have minor roles in the 2000 direct-to-video sequel, as they all attend their newborn niece, Melody's christening. Alana and Arista are not seen in the film but it is likely that they have attended the christening (off-screen).
After the defeat of Ursula's sister Morgana, Andrina is the only one of Ariel's sisters to be seen at the end of the film.
The Little Mermaid III: Ariel's Beginning
In the prequel film, Attina, Alana, Adella, Aquata, Arista, and Andrina all have much larger roles. After their mother, Queen Athena, is killed in an accident, they are all raised very strictly by their governess, Marina Del Rey. When Attina and her sisters discover that Ariel has been sneaking off to a forbidden music club, Attina and the other girls join her the next night.
After Marina discovers the existence of the music club, and that Sebastain is one of the members of the Catfish Club band, she informs King Triton, who swiftly infiltrates the club, orders his daughters to go home and has all the band members locked away in the dungeons, giving Marina Sebastain's job as royal advisor. After being taken home, they are all confined to the palace for reasons Ariel doesn't understand.
The next morning, Attina notices that Ariel is missing and informs their father, who orders his guards to seach for her.
At the end of the film, after Ariel returns home and the ban on music is lifted, they are shown dancing with their father and other merfolk.
Each of Triton's daughters has different hair and eye color in the third movie, but in the first movie, they all have blue eyes.
Originally Aquata was the oldest sister and the heir to Atlantica's throne. However, this was retconned by Ariel's Beginning and switched her place with Attina.
Point of reference, Adella admits in Ariel's Beginning, to being two years older than Ariel, therefore, making her the fifth daughter.
Attina is somewhat of an authority figure among the sisters. This most likely stems from the fact that she is the heir to Atlantica's throne and thus has taken on her the responsibilities of a queen.
Ariel resembles her mother but acts like her father.
Arista is shown in the animated series to have Ariel's attitude just like her father.
Arista's bangs often change sides between scenes.
Another feature between them is that six have different updo hairstyles, while Ariel is the only one with her hair down.
Like in the original story, they are all one year apart from each other.
Although Ariel's Beginning lists their birth order as Attina, Alana, Adella, Aquata, Arista, Andrina, and Ariel, the original film's song, "Daughters of Triton", strongly implies that their birth order was Aquata, Andrina, Arista, Attina, Adella, Alana, and Ariel.
Their tails are the different colors of the rainbow.