HELMINTH-PARASITES OF NATIVE HAWAIIAN FRESH-WATER FISHES - AN EXAMPLEOF EXTREME ECOLOGICAL ISOLATION

The Hawaiian Islands harbor a depauperate native freshwater fish fauna comprised of 4 endemic gobies (Gobiidae) and 1 endemic sleeper (Eleot ridae). We hypothesized that the natural helminth parasite community o f these stream fishes would be depauperate because of colonizing const raints. In the absence of exotic fishes, native fishes in streams of H anakaipi'ai and Nu'alolo valleys harbored no adult helminth parasites. In Hakalau Stream on Hawai'i and Wainiha River on Kaua'i, we found in troduced swordtails and guppies (Poeciliidae); here, the native gobioi d fishes shared species of helminths with poeciliids. They were the ne matode Camallanus cotti, the Asian tapeworm Bothriocephalus acheilogna thi, and the leech Myzobdella lugubris. Such parasitological data shou ld be incorporated into management plans for the conservation of nativ e Hawaiian stream fishes as these parasites have been previously demon strated to cause disease.