Xenopeltis unicolor Reinwardt, 1827

Xenopeltis unicolor Reinwardt, 1827 grows to an average length of about 1 m (3 ft 3 in).

Coloration

Its dorsal color is reddish brown, brown, or blackish, and it has an unpatterned whitish-grey ventral surface.

Head Morphology

As a fossorial (burrowing) species, it has a narrow, wedge-shaped head with little delineation from the neck, a shape that makes it easy to push through soil.

Iridescent Scales

Its most defining characteristic is its iridescent, highly polished scales that give this snake its common name. Each scale has a layer of dark pigmentation just below the surface that enhances this iridescence.

Juvenile Features

Juveniles look very similar to adults, except they have a distinct white collar of scales just below the head; this collar fades within the first year of life.

Visual Capability

This species has two cone opsins, which means it potentially has dichromatic color vision.

Scale Counts

It has two postocular scales, a supralabial scale formula of 3-2-3, 181–196 ventrals, and 26–31 pairs of subcaudals.

Taxonomic Status

It is a primitive snake that shares characteristics with both boas and pythons, and which family it belongs to remains a matter of scientific debate.

Geographic Range

This species is found in China (Guangdong and Yunnan), Myanmar, the Andaman and Nicobar Islands, Vietnam, Laos, Cambodia, Thailand, West Malaysia, Penang Island, Singapore Island, East Malaysia (Sarawak), Indonesia (the Riau Archipelago, Bangka, Billiton, Sumatra, We, Simalur, Nias, the Mentawai Islands (Siberut), Borneo, Java and Sulawesi), and the Philippines (Balabac, Bongao, Jolo and Palawan).

Type Locality

Its designated type locality is Java.

Lowland Habitats

It tends to inhabit open areas such as forest clearings, gardens, and parks, and is often encountered in rice paddies. It can also be found in monsoon forests and rainforests, as well as in rice fields and gardens adjacent to residential areas.

Montane Habitat Preferences

It prefers forest sites in the valleys of mountain streams that have rock outcrops and numerous hollows under stone piles.

Reproductive Strategy

Xenopeltis unicolor is oviparous.

Clutch Size

Females typically lay up to 10 eggs at a time, though nests containing 17 and 18 eggs have been observed.