Unfortunately many suppliers are, inadvertently or otherwise, selling the discos as true giganteus. Because they are typically asking a price appropriate to discos, we believe that there is simply confusion as few have seen true giganteus. A good rule of thumb is that if the adults are smaller than 3 inches, you are looking at discos. If the adults are larger than 3 inches, you are looking at giganteus, which may approach 5 inches. This totally ignores several other inherent differences, including the relative serenity and the pallid transparency apparent in the wings of the giganteus.
Differences are even more apparent in the nymphs.
This species does not climb glass. These roaches are also large typically reaching a length of two plus inches. The nymphs could be said to resemble trilobytes. Ours seem most happy in a setup similar to the Hissers, though a bit less damp and with more leaf litter. Whenever we add fresh leaves to the enclosure, there is a frenzy of activity.