I'm afraid that is not Corydoras sterbai
. The reticulated pattern is quite different, and there is no orange on the pectoral fin spines.
There are two near-identical species that at first glance appear the same. Corydoras reticulatus
and C. sodalis. I have the former presently, I have had the latter in the 1990's. Burgess says the pattern on C. sodalis can be variable, but always the dorsal distinguishes it from C. reticulatus; in the latter, the dorsal has a black blotch, albeit somewhat variable too, whereas C. sodalis has a dorsal with dark bands.
See photos below. C. sodalis is the top and middle fish, note the difference in the reticulation and the second is more like your fish; C. reticulatus is lower fish.
A lovely species, either one. In my experience, tends to remain out of sight more; I catch only brief glimpses when observing the tank, but at feeding times they are out. One of the slightly larger species, growing to about 2.5 inches, what I refer to as medium-large. The "large" are 4+ inches, and the medium around 2 inches; small dwarfs at 1 inch of course.