Amolops hainanensis (Boulenger 1900)

Males are about 80 mm in length; females about 73 mm. Length and width of head approximately the same, with round high snout and rather small tympanum. Lacks vomerine teeth, but with two teeth shaped bones located on the front of its lower jaw. Dorsolateral folds and tarsal fold are both absent. The dorsal surface is olive or dark brown with irregular black or olive specks, and covered with granules and tubercles. Ventral surface is reddish. Toes have large digital disks with horizontal grooves. The toes of hind legs are fully webbed, but with smaller toe disks than the forelimbs’. A thick gland is present beneath the instep. Male has no nuptial pad on its chest, no vocal sac or linea masculina. Eggs are about 2.7 mm in diameter and milky yellow in color. The tadpole is grayish green, about 50 mm long, with about 16 mmhead-body length. Tadpoles have dark specks the back of the body and tail, except for the caudal fin. The tip of its tail is pointy in shape, but not sharply. There is a disk proximal to the mouth. Labial tooth formula is III : 2 – 2 / II : 1 – 1. 4~7 small black protrusions are present on the front edges of the nostrils. There is a pair of small glands located under the back of the eyes, and also a pair of barely visible glands located in the lower abdominal area.

Hainan Torrent Frog resides on rocks nearby rivers with high current velocity or waterfall during the day; on rock near the river bank or bush branches at night. The species is only found in Hainan, China. The elevation of habitat ranges from 80 to 850m.

The breeding season is from April to August. Eggs are milky yellow, bundle into a ball shape, and stick on the grotto walls near waterfalls. The tadpoles reside under rocks in wide, open water where there is abundant vegetation on the banks, large rocks in the water, and high current velocity.

The number of adults have been decreasing. The species distribution is within 500 square kilometers, and the population is severely fragmented. Some of the major threats are deforestation and human consumption.

Amolops hainanensis is a species of frog in the family Ranidae that is endemic to southwestern and central Hainan, China. Its natural habitats are subtropical or tropical moist lowland forests and rivers. It is threatened by habitat loss. It is a sister taxa to both A. torrentis and A. daiyunnensis.