Thanks man. That makes sense.

Would that be due to not being found together in nature or inability to actually produce offspring between the species?

[By the way, thanks for fielding the question]

Right now I have 2 Corydoas habrosus in a 10g tank. I got the last few at the store and now all I can find are C. pygmaeus. Will these two species produce hybrids? Will either of them produce hybrids with C. hastatus? Thanks for any insight anyone can provide.