Who stole my fish?

Once upon a time we had -

2 ordinary goldfish (Ysabella's)
3 fancy goldfish (mine)
3 minnows (Theo's)

Mine, being in-bred and a bit faulty, died first, although they did last well over a year.

When we were last on holiday, Paul killed Ysabella's monster goldfish.

So, I deduced, as there had been no more deaths, or removal of fish (that any one has 'fessed up to) we had 1 ordinary goldfish and 3 minnows.

How wrong can you be - we only have 1 ordinary goldfish and 2 minnows.

So were the fuck has the other one gone?