The Indochinese (or Gray) Rat Snake (Ptyas korros) has a wide distribution extending from India across southeast Asia and southeastern China (including Taiwan, Hainan and Hong Kong) to Bali and has also been recorded (in 1917 and again in 1996) from Indonesian Borneo (Auliya 2002; Zheng et al. 2014).
In Thailand, P. korros occurs up to 3000 m, frequenting forests and agricultural areas.In Java, it has been recorded up to 700 m and is reportedly closely associated with rice fields. During the day, these snakes feeds opportunistically on a wide variety of vertebrates, including frogs, lizards, snakes, birds, mice, and (in the vicinity of human settlements) rats (including Rattus tanezumi [Asian House Rat] and R. tiomanicus [Malayan Wood Rat] ), These snakes, which are semi-aquatic and swim well, apparently feed more on frogs than on rodents (Auliya 2002 and references therein)
Lin et al. (2012) studied geographic variation in several female reproductive traits. Egg-laying date was latest for the most northern of three populations studied and earliest for the most southern population. Most of the other traits examined differed among the populations, but no trait (clutch size, clutch mass, egg shape, variability in egg sizes and relative clutch mass) that differed among populations varied in a geographical trend as did egg-laying date.
Ptyas korros is oviparous. Oviparous reptiles commonly provision their eggs with sufficient resources that hatchlings can still be nourished by post-hatching yolk after hatching. Ji and Sun (2000) studied the conversion of nutrients and energy in eggs and young hatchlings of P. korros.
Zheng et al. (2014) developed microsatellite markers with an eye toward studying gene flow, population structure and evolutionary history of P. korros
Ptyas korros, commonly known as the Chinese ratsnake or Indo-Chinese rat snake, is a species of colubrid snake endemic to Southeast Asia.
Snout obtuse, projecting; eye very large. Rostral visible from above; internasals shorter than the prefrontals; frontal as long as its distance from the tip of the snout or a little longer, as long as the parietals; two or three loreals; a large preocular, sometimes touching the frontal; a small subocular below; two postoculars; temporals 2 + 2; eight upper labials, fourth and fifth entering the eye; five lower labials in contact with the anterior chin-shields, which are shorter than the posterior.
Dorsal scales smooth or feebly keeled on the posterior part of the body, in 15 rows at midbody; ventrals 160–177; anal divided; sub-caudals 122–145.
Brown or olive above; the scales on the posterior part of the body and on the tail often yellow and edged with black. Lower surface yellow. Young specimens with transverse series of round whitish spots or with narrow yellow transverse bars.
Length of head and body 1,080 mm (43 in); tail 700 mm (28 in).[4]
Nepal, Myanmar; Cambodia, China (Zhejiang, Jiangxi, Fujian, Guangdong, Hainan, Guangxi, Hunan, Yunnan, Hong Kong), Taiwan, India (Assam; Manipur; Arunachal Pradesh (Namdapha - Changlang district, Chessa, Chimpu, Itanagar - Papum Pare district), Bangladesh, Indonesia (Sumatra, Borneo, Java, Bali), Laos, Thailand, Vietnam, West Malaysia and Singapore Island.
Ptyas korros, commonly known as the Chinese ratsnake or Indo-Chinese rat snake, is a species of colubrid snake endemic to Southeast Asia.
