This is a goldfish:
...and these are minnows:
Welcome to the discussion
(we should have a fish keeping master thread, I'd be all over it!!)
I fully agree with the overfeeding issue, I actually skip a feeding about once a week, in order to ensure I don't overfeed.
Regarding the Minnows vs Goldfish, I'm gonna have to disagree on the generalization. The "goldfish" that you posted is actually usually called "fancy goldfish", my local Petco and Petsmart sell the "
common goldfish" as feeder fish, those are very closely related to the fancy goldfish (also from the carp/koi family) and what I have at home.