This viper's distribution region is very narrow, and lives only in Tsushima. However, there are a lot of numbers in the habitat. The character is very aggressive compared with G. blomhoffii in the mainland of Japan. The attack style looks like massive pythons such as P. curtus and C. aspera.
Though this viper looks like G. blomhoffii very much, It is possible to distinguish in the point that the spot doesn't exist in patterned the eyeball center.