(A) Dorsal view.

(B) Ventral view.

Overwintering larvae usually occur in some species of lentic-breeding hynobiids (e.g., H. nigrescens, H. lichenatus). The absence or presence of overwintering larvae of H. nigrescens varies by year in a population of Iwamuro-mura, Niigata Prefecture, Japan.

Accompanied Collaborators: Masaichi Kakegawa and Fujio Kishi.