Good question.
Originally it was thought that H. picta was found only in the Pacific Ocean and H. elegans was found in the Indian Ocean. H. picta only had red blotches while H. elegans had brown blotches. Fossa and Nilsen considered them the same species only with different origins. If I recall in the late 1990's it was thought that the number of shrimp species was grossly underestimated and that these were two distinct species. I'm not sure if taxonomists have concluded their study on these as to whether they are different species.
