Agree, Petco and Petsmart won't buy animals from backyard breeders.
"Only the strong survive" only applies in the wild. Fish don't live in tanks in the wild, and they're not thrown into glass boxes with predator fish either.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry