Technically yes, but I wouldn't.
When it was first discovered in 2000, the Coral Red was assumed by the initial describers to be a sub-species of the Dwarf, Nannostomus marginatus
. Weitzman (and colleagues) determined it was actually a valid distinct species, though very closely related, and later in 2001 they named it Nannostomus morthentaleri. You can read more in our profile.
I have both species, and the third (latest) discovery, Nannostomus rubrocaudatus
. It is advisable to keep these three separately. They may cross-breed, given their very close relationship. And there is not much doubt that both N. mortenthaleri and N. rubrocaudatus have evolved (due to isolation) from the original species N. marginatus. The N. marginatus has a very large distribution in Amazonia, whereas the two newer species are each endemic to one river basin. At least, as far as is known.
I have found the two newer species to be hardier than the Dwarf. I have fry from my N. mortenthaleri growing up with the adults.