Age of Aquariums is a novella written by Bobbi J. G. Weiss and David Cody Weiss. It was first published in 1999 and is the twentieth book in the Sabrina the Teenage Witch book series.
Description[]
While cleaning up the school's new aquarium, Sabrina notices some rather unusual underwater inhabitants -- and uncovers the truth behind the mysterious disappearance of the great city of Atlantis.