Choking Hazard for Fish

I got this food clip, based on PETCO's recommendation to clip on orange wedges for my goldfish to boost their immune system and their color richness. But one of my small goldfish died because of choking, after trying to swim through the toy fish's tail hole....It got stuck in that hole, as it tried to swim through the hole from inside...

PETCO, time to wake up and start making real recommendations, if you want to call yourself as a speciality pet store, and not just an animal barber shop...

2 straight recommendations from them completely killed my Fishtank at home...