here is a quote from the man I bought them from . . .
"I don't see why it couldn't work.
If anyone said you can't keep fenestratus with synspilus or
something, I only have to think back about 20 years ago when
I kept only individuals of each species I could get my hands
on.
In a 125, for several years I maintained the most awesome
fenestratus and synspilus I'd ever kept. Also in the same
tank were trimac, dovii, managuense, citrinellus, big fancy
loricarids, predatory Pimeloid and Bagrid cats, and a Lates
for a while.
It's not always the case that purchasing 9 juvenile cichlids
means you will still have the same 9 adult cichlids in a
couple years, but we try-right?
Enjoy the fish and watch them grow."