Thank you, Ed. The article did mention C. orientalis by name, but not pyrrhogaster, saying that orientalis & Bomina have similar temperature & dietary needs, so will mix OK. I currently have orientalis & pyrrhogaster in the same tank & have added some guppies (accidentally) that are also thriving. The pyrrhogaster have bred & produced offspring, as have the guppies, so I know that my well-established tank is meeting their needs. I know many people think species should never be mixed, but I feel they can be, as long as you're mixing appropriate species AFTER you've done the research.