This species is known from several districts in western Japan, i.e. Chubu District (Gifu and Aichi Prefectures), Kinki District (except for Kyoto and Hyogo Prefectures), Shikoku District, and Kyushu District (except for Saga and Nagasaki Prefectures) (Tominaga and Matsui 2008). Its altitudinal range varies between 200 to 1,800 m asl (M. Matsui pers. comm. August 2009).
Habitat and Ecology
This species is found in montane forests near the headwaters of streams (M. Matsui pers. comm. August 2009). It lays eggs in small, underground streams, where the larvae hatch and metamorphose without feeding (Tominaga and Matsui 2008). The breeding season for studied populations is from May to June, and clutch sizes vary from 7 to 19 eggs (Tominaga and Matsui 2008).
This species is common within its distributional range (M. Matsui pers. comm. August 2009).
In the southernmost part of this species’ range, locals have indicated that beech forests on the mountain top where the species lives are changing to bush forests (M. Matsui pers. comm. August 2009). The past condition and causes of change need to be further investigated. Local, disjunct populations may be at greater threat of habitat change (M. Matsui pers. comm. August 2009).
It likely occurs in several protected areas.
This species has recently been identified as pertaining to Hynobius naevius yatsui and has been elevated to full species rank (Tominaga and Matsui 2008).
Matsui, M. & Angulo, A. 2009. Hynobius yatsui. In: IUCN 2014