Even Moody Acquario (fish tank cum bath tub)
By Even Design of Italy (who, I believe has gone out of business), comes this $15,000.00 free standing tub that has a built in aquarium. Part of their Moody collection which includes the vanity and toilet I posted on here years ago. If you can afford it, it's available here for purchase (but I don't think they'll ship to the US).
A fish tank combined with a bath - wonderful