Abstract
Japanese giant salamander, Andrias japonicus inhabits in the Maefukase and Kawakami Rivers of the Maefukase River system in Iga City, Mie Prefecture, where construction of a dam is planned. Disjunction of local populations and subsequent reduction of each population within the river system may induce loss of genetic diversity and ultimate extinction in each local population. In order to assess current status of genetic diversity among salamanders in this river system, we surveyed nuclear DNA diversity through AFLP method. The result indicates that the method is effective in differentiating salamanders of this and adjacent river systems from congeneric species and conspecific populations from remote rivers that have been differentiated by mitochondrial DNA. However, this method could not detect presence of specific genetic groups among salamanders from the Maefukase and adjacent river systems. Genetic structure in each local population of salamanders within this river system is judged to be not fixed. On the other hand, frequent gene flow among local populations is not surmised, either. Genetic structure in this river system seems to be complex, being strongly affected by forced movement of salamanders by floods and by artificial relocation. For the discussion of local population disjunction, we need further basic data using more sophisticated methods.
