No abstract

Species identifications of the Pacific lamprey Entosphenus tridentatus from four other Japanese lampreys, Lethenteron japonicum, L. kessleri, and two undescribed Lethenteron species (L. sp. N and L. sp. S), were carried out on the basis of random amplified polymorphic DNA (RAPD) using the polymerase chain reaction (PCR) method. Of 65 RAPD loci, seven loci possessing species-specific fragments were obtained for E. tridentatus. Based on these RAPD loci, four larval individuals of E. tridentatus from the Naka River (eastern Honshu Island, Japan) were recognized in 2001 and 2002. The existence of larval individuals of E. tridentatus, as well as spawning adults previously reported from the same river, indicated the possibility of residence in that species.