Semisulconspira libertina is a black snail and lives in clean rivers throughout Japan. This snail in known as a food for larvae of the firefly, release of snail to protect fireflies has been done. Genetic pollutions caused by release of foreign snail are concerned. To obtain informations useful for maintenance of genetic diversity, we investigated the genetic population and geographic relationships of Semisulconspira libertina sampled from 50 points including Kumagawa river system, Hikawa river system, and Midorikawa river system in southern Kumamoto Prefecture, Japan. A novel method for readily extract mitochondrial DNA from foot tissue has been developed. For this assay, mitochondrial COI gene was not suitable, because it shows heteroplasmy in some individuals. On the other hand, mitochondrial 16S rRNA gene are homoplasmic. Total 189 of mitochondrial 16S rRNA sequences were compared by clustalw multiple alignments and resolved into lineages by generating phylogenetic trees. However, most of clones were distributed over several regions, a few clones show region specific localization. Such region specific clones are useful phylogeografic investigations and maintenance of genetic diversity.
