Hynobius formosanus (Formosan Salamander)

Details

Hynobius formosanus—the Formosan salamander—is a Taiwan‑endemic hynobiid inhabiting cold headwaters and mossy montane forests. Mostly nocturnal and secretive, it shelters under stones, logs and within crevices.

Ecology & Biology

• Diet: small arthropods (insect larvae, isopods, springtails) taken among moss and leaf litter.

• Reproduction: external fertilisation; females attach paired gelatinous egg sacs beneath stones/wood in cool pools or slow stream runs. Larvae are stream‑dwelling with external gills and metamorphose after months to ~1 year.

• Seasonality: breeding in late winter–spring; strong dependence on cold, well‑oxygenated water.

Identification

• Form: small–medium hynobiid with distinct costal grooves.

• Colour: dark brown to blackish with fine pale speckling; paler venter.

• Limbs/Tail: short limbs; laterally compressed tail aiding swimming.

Size & Longevity

• Total length: typically 8–12 cm, up to ~14–15 cm.

• Life: roughly 6–12 years (wild estimate).

Range & Habitat

Montane Taiwan (e.g., Hehuanshan and adjacent ranges) around 2,000–3,000 m, in spring‑fed headwaters, seepage pools and humid conifer–broadleaf forests; typically under stones, moss and woody debris.

Conservation & People

• Threats: road/recreation disturbance, stream modification and water‑quality change, habitat fragmentation and climate warming.

• Measures: protected in parks/reserves and by Taiwanese law; avoid trampling/stone‑turning in headwaters.

IUCN: Near Threatened (NT) (check latest assessment).