At the time of survey, 18 pairs of egg sacs and four single egg sacs, including 9-38 embryos from the 8-cell stage to the mid tail-bud stage, and two aquatic-phase males (one was typical but another was not) were found in the water.

In general, this species is characterized by the absence of striations on the egg sac envelope (Matsui, 1987). However, egg sacs with the striae on their outer layer occasionally occurred, like those of Hynobius lichenatus.

Accompanied Research Collaborators (alphabetical order): Masaichi Kakegawa (Tokyo Metropolitan Komatsugawa Senior High School), Fujio Kishi and Yuko Saikawa (Shirouma Association of Naturalists), and Koji Takada (Nagano Chausuyama Zoo).

Matsui, M. 1987. Isozyme variation in salamanders of the nebulosus-lichenatus complex of the genus Hynobius from eastern Honshu, Japan, with a description of a new species. Japanese Journal of Herpetology 12: 50-64.