C.sterbai, C. dulpicareus, and a few other species are often suggested for discus (= blue ram temperature range) because of the warmer temperatures. I personally don't accept this, and in talking to Ian about temperature he did say that no cory species should be permanently kept at such high temperatures. It would be helpful to have a log of the water temperatures seasonally of rivers and streams, but this would take an immense amount of research and while there is data for some watercourses I doubt there is for many others. And of course there is usually a variance with water depth, and diurnally even if these may not be significant.