There are several kinds of animals that people own.
Wild animals like tigers, bears and such: These animals tend to live longer than they would in the wild. Many are taken care of very well and prized possession. They tend to have a very lazy life because they do not need to hunt for food in the wild and the more tame ones have a fair amount of freedom.
Livestock like cows, chickens and such: These animals never existed in the wild, at least not in their present form. They were bread to fit the needs of man as a food source. Had it not been for the owners, these animals wouldn't even exist. If left to the wild, they would quickly fall prey to wild animals or just starve to death because man is not around to provide them food over the winter.
Pet like dogs and cats: Sure, there are some owners who are cruel to the animals but others treat them like a member of the family. When I was a kid, I had a dog of my own. She was my responsibility. I took care of her, gave her food, water, and shelter. Because I trainer her well, she never even had to be on a chain or leash. She never fled even though we did not have any fences. She saw our property as her home as well as ours. At home, she was always by my side even if I did not call her to be there. She was there because she wanted to be there.
Other pets like fish sill are wild animals but with smaller areas to roam. They also have a lazy life where they don't have to seek out food. They also tend to have much longer lives than their wild relatives.
In the case of the fish that is being cleaned, first off this is not an animal that is owned but hunted for food. Usually when cleaning a fish, the first people tend to do is remove the head or gut it. A quick death instead of trying to remove the scales before it dies. In the wild, these animals may not get quite a quick death, many animals tend to give multiple less fatal wounds to their pray before going for the kill, this is so the animal will be weaker and less likely to fight back when they do kill it. Sometimes an animal will injure it's prey, drag it home, and let their young attack it so their young can get some hunting experience before joining the hunt. Imagine being a wild animal that gets his body broke to the point your barely alive, then dragged a great distance just to be tormented to death by the young of the animal that crippled you. Ya, being in the wild is much better than being owned by human.
Do you really think a little lap dog or a goldfish even a lizzard that's has beeen domesticated for years would have a better life in the wild. Having them as pets greatly increases thier lifespan and quality of life in most cases . So allowing theese animals into the wild they would die fast . So keeping pets is doing them a favor you feed them water them play with them protect them shelter them ( yes sometimes people don't do those things but most people do )
Animals cannot be considered slaves because they cannot perform any duties for us. Fish don't clean our houses and dogs don't cook us food. The definition of a slave is a person who is forced to obey their owner. Animals cannot be forced to obey because they cannot comprehend human language unless they are a domesticated animal. If it is a domesticated animal it has adapted to a human environment and is living it's life how it is supposed to.
Animals are a separate category of being; while we share much with them, our ability to reason necessarily places us above them. As such, we have the right to use them to our benefit. We own, buy, and sell land or plants, yet no one equivocates that with slavery. Likewise, we ought to be free to hold animals for labor, food, or diversion.
The vast majority of all animal life forms do not have a consciousness, are not self-aware, and have no free will. Their emotions are simple and directly tied to basic, pre-programmed instinct. If you would not give citizenship rights to a certain animal, you cannot give them the same special treatment that humans receive. Purposeless deliberate abuse of anything is bad, but it is also wrong to try to anthropomorphize non-human animals that are inherently limited in their physiology to ever reach a human's level.
They are owned and sold to anybody even people who have been caught and horrible things are going to happen to some of them. Almost all of them are locked in tiny cages and aquariums sometimes without any companions. And id say that this is worse than prison is for a human in alot of ways because animals dont have tv like humans do and cant get any pleasure from them, they cant go outside and alot of times cant even get out of human hands when they are let out of their cages or aquariums, and people get tired of them and dont let them out at all. Id say they are safer but that just turns out to be a bad thing because dieing in this scenario would be a good thing even if they dont know it. Their fate is put into the hands of sadistic little kids sometimes and from my experiences a lot of kids abuse and even torture animals. And people even clean fish while they are alive and fish do feel. Just because it doesnt show its pain you assume it isnt going through any. Lol and if people didnt know that slavery was wrong then how can you say you know that this isnt wrong?
Is light slavery could be so wide but most importantly its ownership of a living thing. You may not make money but in somecase people do make money off your slave.
We neuture. Feed. Walk. Give limited freedom.
Sell theyre offspring. When they die. We replace them.
Theyre should be no price on LIFE!
If you adopt a animal tje only price should be for medical and living exspensive at most amymoney giving to the previous owner shpuld be a thank you.