According to Disney, King Triton, ruler of the see in The Little Mermaid, is quite the naming buff (or maybe its his never-seen wife?). He has seven daughters, all with complex "A" names, ending of course in the main character Ariel. Her is some "under the sea" inspired names for you!
Attina - A name with unknown origins, used infrequently. Possibly a take on Athena (Greek goddess of wisdom, strategy, and heroes. Possibly a female version of the ancient Macedonian name Attinas. Also a place name - there is an Atina, Italy, an Atina, Greece, and an Atina, Turkey (as well as an Atina, Ohio, because the U.S. loves to borrow place names). Or, just play on the common name ending/nickname Tina.
Aquata - With Aqua right in it, its hard to miss this beinga play on the word for water (especially as it is assigned to a mermaid in this case). It is actually a Latin word meaning "having a watery constitution".
Adrina - This is a variant of the Latin name Adrienne, meaning "from Hadria".
Adella - A variant of the Old German "Adela" or "Adelaide", which all mean "Noble and Kind".
Arista - A Greek name meaning "the best", related to the word Aristocrat, comes in variant forms Aristella and Aristelle.
Alana - A derivation of the masculine Alan or possible old German Elaine. Depending on how you come to it, it could have many different meanings and is a rather modern version of the name.
Ariel - And here is the big one, the one that is officially a "Disney Princess". I was quite young when Little Mermaid came out and the movie was my very first reference for that name. I was astounded when I was bit old to meet a "real life" Ariel. I am pretty sure I can (and maybe should) write an entire post about using Disney Princesses names. Anyways, Ariel is Hebrew name meaning Lion of God, and originated as a boys name.
Would you use any of these names? I find Adella and Ariel quite appealing. Is there any great "a" names that fit with this group that you are surprised Disney didn't use? My own name, Amanda, fits into the song quite well but isn't exotic enough for a Mermaid!