Inbreeding amongst wild Angels

#1
Hello to all the experts.. A question purely out of curiosity..
Was thinking if angelfish (or any other fish species for that matter) tend to inbreed in the wild, or is there some natural instinct that pushes them away from their own siblings. Wonder if there is any research done on this?

Also when angels are kept in an aquarium, with both there own siblings and unrelated ones, do they tend to form pairs with the unrelated ones?
cron