> Those species do not care about ethics. Our discussion started from ethics, which is uniquely human. We are not discussing if a behavior occurs in nature. We are discussing if that behavior is ethical for humans.
Those species also don’t care if they’re domesticated or enslaved. The cow doesn’t care if it’s milked, so long as it’s done gently, indeed it seemingly enjoys it and will avidly seek out a milker. The cow doesn’t care if any excess of milk surplus to its calf’s requirements is taken from it, indeed it will loudly call for it to be taken. The cow doesn’t care about consent, or the fact it hasn’t given it (and can’t)… the cow cares only for ample water, some salt, good grass, a warm and dry place to sleep, a minimum number of flies, an occasional burp, someone to remove the pies that keep piling up everywhere, and nothing nearby with claws or teeth. If its “enslaver” provides all of that, the cow wouldn’t (and couldn’t) consider itself “enslaved”.
Is it ethical for a human to consume the meat of a cow? Sure… right up until that human seriously engages with ethics. Is it ethical for them to continue to treat as domesticated a species that has adapted to that domestication? Yes, or that species will suffer an environment it’s no longer adapted for. Is it more ethical to do so without consuming the animal’s meat? Sure, or at least until after that animal’s natural death. Is it more ethical to do so without consuming the animal’s milk? No, not inherently, because the cow does not have to suffer for that milk. If I have a cow and I care for that cow and that cow wants rid of some excess milk and I rid it of that milk in a caring way then there’s no cognizable ethical reason for me to not consume the resulting milk, any more than it would be unethical of me to eat the cast off skin of a snake or unfertilized eggs in an abandoned nest or apples fallen from the tree. Is it more ethical of me to consume only the dairy I know was sourced in an ethical manner? Of course. Should we move towards an entirely symbiotic relationship with the species we’ve domesticated? One that isn’t parasitic? Absolutely, and we certainly should… and the further the degree to which we do the less we can cast that symbiosis as slavery and still sound reasonable.
One hopes the decorator crab and the anemone evolve towards that mutually-aiding symbiosis as well; and one hopes if the former ever evolves to consider ethics it then walks a long road towards expanding its circle of empathy to the point where it considers caring for the weird little death-dealing hairball on its claws. But where it discovers said hairballs have been evolved to suit those claws it shouldn’t feel particularly guilty for benefitting from the symbiosis that has now attained.