Charlie lived in a small tank in our living-room...outliving his gold Goldfish companions, and eventually out-growing the tank.
So...I purchased a new tank, with a whole new garden of plastic water plants. Na purchased a couple of new friends for Charlie. Life was good, and Charlie continued to grow.
We left Charlie, and the cats, in the capable care of P'Dom, our ex long-term maid/nannie/factotum when we travelled up-country for an xmas/new year break, and arrived home to find that Charlie was [mostly] no more.
P'Dom said she arrived one morning to find a small puddle of water next to the tank, and [behind the sofa] Daisy feasting on fresh silver goldfish. P'Dom thinks Charlie got boisterous and leaped right out of the tank and onto the floor where Daisy did the humane thing by eating him.
Daisy seems to be spending a lot of her time with her head semi-immersed in the fish-tank...I suspect the tragic events unfurled a little differently...