It can be difficult to select suitable tank mates for parrots as they are a man-made hybrid species and as such their temperament towards other fish is very variable. Look for fish from the same area as the suspected original species' used to create the parrot (i.e. Central America) who will therefore tolerate the same water conditions. Stick to larger, more robust species such as Swordtails, possibly some other CA cichlids such as Convicts(but don't get a male/female pair as there will be problems with them when they breed).
Yep, unfortunately so! Humans aren't content with line breeding gross deformities into fish, so they create a mutant hybrid, the only upside is they are sterile (as far as i know) so won't create babies on their own without more human intervention! I imagine there are some that do get dumped, but I haven't ever heard about them being found anywhere. Could be a problem in climates where they could live outside, but other than being a nuisance, due to their deformities aren't really a threat to much, they aren't good swimmers and their mouths are often quite deformed, so may struggle to feed themselves on anything a normal cichlid may be able to hunt down.
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