According to The Hollywood Reporter, Sara Paxton will star as the title character in Aquamarine, a Fox 2000 comedy that Elizabeth Allen is directing.
Based on an Alice Hoffman children's book, the story centers on two 12-year-olds who discover a mermaid named Aquamarine (Paxton) in their beach club's swimming pool.
Teen pop-star JoJo and rising tween star Emma Roberts already have been cast as the two girls. Rodney Ferrell and Erin Lindsey are overseeing Aquamarine for Fox 2000 topper Elizabeth Gabler.
Paxton, star of NBC/Discovery Kids' "Darcy's Wildlife," appeared in MGM's Sleepover and had a reoccurring role on the WB Network's "Summerland."