I am new to the fish as petís thing. I setup 2 tanks 1 55G for my bala and rainbow sharks, and then bought two swordtails for a 10G for my girl friend. Being new to fish I didn't notice I got a boy and a girl swordtail until the next day when I started researching. I was going to take one back in exchange for another of the same sex so I had no babies, but then I got to thinking this may end up being a source of free snacks for my sharks.
Does this seem unethical? And will these two breed in my 10G tank. I didn't get them for this but it seems like it might be a way for my sharks to get a nice treat a couple times a year.
A lot of keepers raise feeders for other fish. I am actually keeping White clouds in a tank that will have a blue crayfish in it. I expect the cray to pick one off here and there. As far as I am concerned, it is better to raise your own feeders than to buy them and if this means you control a population of fish at the same time, why not. This makes sure that the feeders are in quality shape and you don't have the potential probems from buying feeders of introducing parasites and disease.
I agree with the above postings. The fact of the matter is some fish are predators and require live food. I have not eaten meat or fish since I was 12, but I'm perfectly comfortable feeding live critters to my fish. I know that I am capable of getting proper nutrition without eating meat, but this is not true for some of my lovely pets. It seems a lot more ethical to raise your own feeders than to buy them, as most feeders are raised in horrible conditions. At least the ones you raise will have happy, healthy lives before they become a snack.