Amolops caelumnoctis Rao & Wilkinson 2007

Amolops caelumnoctis is a relatively large ranid frog, with males measuring 71 to 74 mm in SVL and females 78 to 91 mm. The head is dorsoventrally flattened and longer than wide, with large, bulging eyes, a sloping snout and a rounded canthus rostralis. This frog lacks a pineal body on top of the head. The tympanum is small and distinct. Vomerine teeth converge backwards. The tongue is deeply notched. Vocal sacs and apertures are absent. This frog has smooth skin dorsally and ventrally, lacking both tubercles and dorsolateral folds. However, it does have distinct temporal folds. The arms are somewhat robust and long. The fingers in contrast are slender and long, with the third finger almost as long as the forearm. The fourth, second and first follow in length. The tips of fingers II to IV expand to discs with circummarginal grooves. There is no webbing or lateral fringe on the hand; however, the toes are fully webbed. The discs on the toes are smaller than those of the fingers. Oval subarticular tubercles are present on all toes. The inner metatarsal tubercle is narrow and slightly bulging, while the outer metatarsal tubercle is absent. Males have nuptial pads on the base of the first fingers, thicker, shorter arms and shorter hands, a much larger inner metacarpal tubercle compared to the outer metacarpal tubercle, and slightly smaller dorsal spots when compared to females; also, vocal sacs are lacking in A. caelumnoctis males. The dorsum, flanks, head, fingers and toes are dark purple with yellow spotting. Spots on the flank are larger than those on the dorsum and overlap. The eyes are dark brown with yellow flecking and a yellow ring around the iris. Ventral surfaces are light blue (throat, chest, limbs), gray (abdomen light gray anteriorly, mottled dark gray posteriorly, groin dark gray with white flecks), or white (throat, chest). Ventral marking varies: arms are light blue to white ventrally without marking; thighs are light blue ventrally with black reticulations; the tibia and tarsi are light blue ventrally with tiny yellow spots. Palms, soles, finger/toe discs, and hand/foot tubercles are gray. Toe webbing is yellow.The specific name is derived from Latin meaning the sky of the night, referring to the yellow spotting on the dark purple background resembling stars in the nighttime sky. It differs from other species of Amolops by its smooth skin, lack of dorsolateral folds, lack of transverse bars on the legs, and lack of a visible pineal body.

It is distributed in the mountainous areas of Jinping county, China. These areas border on northern Vietnam, where it has not yet been found, but its range could thus possibly extend into Vietnam. This species lives in mountain streams of heavily forested mountains and has been found at an elevation of 2400 m. The fast-flowing streams are sandy-bottomed with large boulders inside or adjacent to the streams.

Amolops caelumnoctis was observed breeding in the early spring, in March. The breeding season appears to be short, lasting about a month, in contrast to the sympatric species A. tuberodepressus, which breeds in June and July.