The Daughters of Triton

King Triton has seven daughters. In the musical debut in the concert conducted by Sebastian, the daughters introduce themselves in the following order [Ariel is not actually present]:
Aquata
Andrina
Arista
Atina
Adella
Allana
Ariel

Each can sing extremely well, and each has a different color fin and shell top, as well as different varieties of hair colors.
There is a song dedicated to them called Daughters of Triton.

Daughters of Triton

Ah, we are the daughters of Triton
Great father who loves us and named us well
Aquata, Andrina, Arista, Atina, Adella, Allana
And then there is the youngest in her musical debut
Our seventh little sister, we're presenting her to you
To sing a song Sebastian wrote
Her voice is like a bell
She's our sister, Ari--

More

The Daughters of Triton in Disney Princess Magazine
Icons of the Daughters of Triton