(A) A male of Hynobius nigrescens captured during April shortly after emerging from a breeding pond in Iwamuro-mura, Niigata Prefecture, Japan, a left forelimb of which was lacking (ventral view). He was very slender in comparison with other males in the same period.

(B) X-ray photograph of Fig. A. Note the complete absence of bones and ossified cartilages, which correspond to the limb girdle of the left forelimb. A V-shaped structure seen in the cranium is a prevomerine teeth series.

A male H. nigrescens without a right forelimb has been found during the breeding season (Uchiyama, 1975).

Uchiyama, M. 1975. Absence of right forelimb in Hynobius nigrescens. Niigata Herpetological Journal 2: 7-8. (In Japanese)