The snout is truncate in dorsal view and obliquely projecting in vertical profile.

[2] Pelophryne api occurs in primary lowland and montane rainforest in limestone karst areas at elevations of 65–1,200 m (213–3,937 ft) above sea level.

[6] Individuals have typically been encountered in low vegetation (0.2–0.5 m (1–2 ft) above the ground) at night.

[2][6] The eggs are deposited in small pools on the forest floor[1] (solution holes in limestone, hollowed dead leaves, logs, or senescent Nepenthes pitchers[2]).

[1] Although the known range of this species is limited, it is abundant and common in suitable habitat in Gunung Mulu National Park.