Yeah P. Scalar is a different species than P. Altum. They are often mismarked like that, and sold as Altums. The angels you buy at a LFS are P. Scalars, I do heavily favor the wilds tho.
True Altums, if not heavily medicated as soon as they arrive state side rarely make if very long. The only people I know who have been able to keep them alive long imported them themselves.