Lisa Morel, who had appeared as Aquagirl had appeared in Adventure Comics #266 in 1959, 8 years before Tula first appeared in 1967. She was one of several Atlantean children born unable to survive under waters, and were sent to the surface to live with the land-dwellers. Adopted by the scientist Dr. Hugo Morel and his wife, however when Aquaman was in danger, Lisa's water-breathing powers awoke. Creating a costume identical to Aquaman and using the name of Aquagirl, she fought alongside him. However, her powers were brief and she lost them permanently.
Lisa Morel was created by Mort Weisinger and Ramona and made her first and only appearance in Adventure Comics #266 in November 1959.