Until recently, it was thought that there was just one species of āhole here; fisherman, though, recognized two morphotypes, and recent DNA analysis* has confirmed the knowledge of the locals. Kuhlia xenura and Kuhlia sandvicensis are difficult to tell apart, but as juveniles (juvies are called āholehole) Kuhlia sandvicensis sport zebra-like markings on the head, favor tidepools with an open-water connection, and do not appear to venture well up into freshwater streams as their more abundant counterparts do. Despite its species name, Kuhlia sandvicensis is not endemic to Hawaiʻi, but xenuria is - this mix-up a result of the earlier taxonomic confusion. No matter to the fishermen though, who know theyʻre both ʻono loa.
* ASPECTS OF THE BEHAVIORAL ECOLOGY, LIFE HISTORY, GENETICS, AND MORPHOLOGY OF THE HAWAIIAN KUHLIID FISHES by Lori Keene Benson, 2002.