Doctor of Philosophy (PhD)


Biological Sciences

Document Type



Flagtails, members of the Genus Kuhlia, are Indo-Pacific fishes found in marine and freshwater habitats. Known locally as āholehole, they are important food fishes in the Hawaiian Islands and were often used by Hawaiians in traditional ceremonies. Local fishermen have noted the presence of two morphotypes in Hawai'i, although at the beginning of this study only one species, Kuhlia sandvicensis, was identified in the scientific literature. For this dissertation research, morphological and DNA studies of the two morphotypes determined that two species of the genus Kuhlia do exist in Hawai'i. Subsequently, Randall and Randall (2001) published a revision of this genus, which included a description, based on limited meristic evidence, of the "big-eyed" morphotype as Kuhlia xenura. This fish is apparently limited to Hawai'i, and it is the species found commonly in freshwater streams. In addition to the morphological and DNA analysis, I investigated the life history of both Hawaiian Kuhlia. Electron microprobe techniques were used to analyze otolith daily increments to answer questions about whether freshwater use was obligate in these species' life cycle. I found that K. xenura's use of stream habitats is facultative, although all individuals examined had spent time in fresh water at some point during their life. Kuhlia sandvicensis individuals also resided in water of decreased salinity at various points in their life cycle. However, there appears to be differences in habitat preferences by the two species, with only K. xenura residing in freshwater streams. Future research comparing their ecology will provide a greater understanding of the importance of streams and tide pools as nursery habitats for these fishes. Due to the former recognition of Hawaiian Kuhlia as one species, management strategies currently in place are possibly more relevant for one species than the other. Thus, conservation plans for both āholehole should be reconsidered in light of my results that these two "types" are separate species with genetically distinct populations. Their status as popular food fishes, coupled with the evidence that K. xenura appears to be endemic to the Hawaiian Islands, makes proper identification, monitoring, and management practices essential for their conservation.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

J. Michael Fitzsimons