There is actually a poem by Thomas Gray (1716-1771) called Ode on the Death of a Favourite Cat, about a cat who drowned in a china vase:
I.
'TWAS on a lofty vase's side,
Where China's gayest art had dy'd
The azure flowers that blow;
Demurest of the tabby kind,
The pensive Selima reclin'd,
Gaz'd on the lake below.
See entire poem at http://www.potw.org/archive/potw90.html (And I think, technically, the plural is "goldfish".)