Where exactly did Aulonocara "eureka" come from?? It is still debated today, but the consensus is that it is a cross between Aulonocara jacobfreibergi "otter point" and an Aulonocara jacobfreibergi "swallow tail" AKA reginae, carolae, catherinae etc. So it depends on how much of a purist you are??? Personally I consider it a cross/hybrid. They are from two different locations and have different coloration, both very beautiful in their own rights.
Eureka has established itself so well in the hobby, that it is nearly impossible to find "otter points" or "swallow tails" in the hobby. Both species are found in the southern part of the lake, inside the Malawai National Park where collecting for the ornamental fish industry is not allowed, however catching fish for food is. Doesn't make sense to me? ... and I just hope I am not the only person that is working with these two natural occurring species.