I doubt it will last long but about 5 years ago, I had a load of malawis born on a system and the babies got washed through the weirs and pipes into the sumps and that's where most grew up! But very occasionally a baby or two would go through the pump and get returned to the tanks... but where they came out was hit and miss! Most of the time they are like a food being shot out of a pipe!
But I did have a pair of mbuna fry of dubious heritage end up in with a few guppies and I left them there, eventually more guppies were put in the tank and they disappeared but a week or two later I noticed them again swimming madly around with the guppies.
By sub adulthood I discovered they actually couldn't cope with living with other cichlids, they had no idea what to do and got battered by cichlids a third their size!
Went to a customer with livebearers who was willing to trial them and bring them back if need be. As far as I heard they lived happily ever after.
I was just surprised at quite how different they were to cichlids raised with their own kind, the ones raised with guppies were more stupid, food orientated and even hounded female guppies with the rest of the males, was bizarre.
Needless to say I felt somewhat guilty and screwing the fish up!