Other members of the genus "Diphyllobothrium" include "D. dendriticum" (the salmon tapeworm), which has a much larger range (the whole northern hemisphere), "D. pacificum", "D. cordatum", "D. ursi", "D. lanceolatum", "D. dalliae", and "D. yonagoensis", all of which infect humans only infrequently. In Japan, the most common species in human infection is "D. nihonkaiense", which was only identified as a separate species from "D. latum" in 1986. More recently, a molecular study found "D. nihonkaiense" and "D. klebanovskii" to be a single species.