Airbreather fry Specially labyrinths often enjoy temps at their high range. Betta fry do best between 82-84 F. but they are able to catch pnemonia in the labyrinth organ.
I think cories only "gulp" air into their gut or swim bladder. So I can't help ya.
Someone here just bred a boatload of cories..bet he can tell you
"Fish! Thank You! Oh, tropical huh? Did you buy a heater? Auuugh!"
Mega-pet stores prolly should not be allowed to sell animals as retail "items".