We are owned by four cats and who knows how many fish. The four fur-beasts think that they own the house, and us as well. Still, they are mostly well behaved - unless they fight over who gets to sleep in the bed, or decide to investigate our dinner.
Of course, each of the four cats is convinced that we have three too many cats! They also shed enough fur to make a whole new cat!
The fish books we bought described the difficulty of breeding fish, and contained a plethora of clever ideas on how to entice fish to breed. I guess the fish never read those books; they've been doing fine on their own! When we bought the fish, we didn't realize that it was a "buy two, get two hundred free" offer! "Good Golly, Miss Mollie!" Thankfully, the pet store took the babies once they were about 6 weeks old.