On the topic of better lives in captivity, here is something I saw once:
I was at a zoo, I when I was younger, I remember seeing rainbow sharks (I didn't know that was what they were then, but do now) and they were of the 6" you are told they grow to, they were reaching 12" some a little more.
Why was this?
Because a lot of sizes are based on natural settings where the fish dont get the food they need all the time, so they dont grow as big. They dont get to that size as they are normally eaten before then, in the tank the food change is more lateral.
So take 'fishy A' he lives in the wild and 'fishy B' he lives in a tank, they are both the same species.
'fishy A' spends all day hiding and rushing in and out of his hiding spot for food.
Where as 'fishy B' spends all day swimming about and exploring, and eats when his owner open the lid and drops in some food.
5 days later 'fishy A' is eaten by a bigger fish, on the same day 'fishy B' gets a new friend who turns out to be female and they have babies.
which fish was better off? IMO 'fishy B' he had no worries or stresses, well until the female was introduced (/me waits for the female population here to strike back at that comment) and was regularly feed.
At the end of the day most people who preach about stuff like this, cruelty to animals, war, etc etc etc... have no clue about what they are preaching about. They have read a leaflet and been told what to think by some crazed fool, who themselves has not clue.
Stupidy and ignorance breeds between liked minded and impressionable people.
Prove them wrong, my friends think I'm barking mad with all my fish, but hey I enjoy it and so do my fish.
My female likes me too much and would like to eat my hand as she has tried on numerous occastions.
and breathe......