Slug Snakes

Southeast Asia Snakes

Snakes ~ Slug Snakes

Slug Snakes are an arboreal genus of slug-eating snakes with a blocky head shape and special lower jaw that has fangs positioned anteriorly. This unique morphology enables them to extricate slugs and snails from their shells. This oviparous species occurs through Southeast Asia in Malaysia, Thailand, Indonesia and Borneo in a wide range of rainforests and hilly habitats.

Nocturnal in nature, slug snakes will craw through bushes and shrubs in search of slugs and snails. Once it detects prey, the slug snake will latch on quickly on the snail or slug's exposed bit. If the slug has withdrawn too deeply inside the shell, the slug snake will slide its lower jaw in while its upper jaw clamps on the shell. The lower jaws will then hook the flesh of the snail and extricate it slowly.

The blunt headed slug snake, Aplopeltura boa, has a highly-variable colouration and patterning. The eyes are large and a large patch of white covers the labials, jaws and cheeks. A small stripe runs from the orbit to supralabial scale below it. Its colour ranges from being chocolate to greyish brown with white or yellowish markings at the flanks and ventrals. The patterns on the body are highly variable, some individuals may have a solid colouration while others while be heavily mottled with irregular bands and splotches. It can be found in lowland to mid-level rainforest.

The keeled slug snake, Pareas carinatus, is a tiny-bodied slug-eating species that is common throughout lowland and mid-level rainforest across the Peninsular. The body is brown and a row of spots that run on both sides of the vertebral margin may be present. A thin postocular steak runs from the orbit to the nape of the neck. The ventrals are yellowish brown. This species also occurs widely in Borneo.

The vertebral slug snake, Pareas vertebralis, is a highland species that occurs in hilly and montane rainforest, from 800 m onwards. This species is a solid greyish brown, except for the whitish ventrals, with red irises in adults and yellowish to orange in juveniles. Juveniles also have faint dark bands across the body, but this disappears in adulthood. Some adults may have a lighter colouration while keeping oblique bands.

Pareas margaritophorus, or the white-spotted slug snake is a beautiful species that is known from mostly lowland rainforest. It occurs throughout Peninsular Malaysia but is more abundant in the north. The body is purplish grey with a series of transversal white and black spots arranged as irregular bands. Juveniles have an orange to red collar that eventually changes to white or yellow in adulthood. The ventrals are white with generous black speckles, especially on the ventrolateral area.

The rows of special teeth used for gripping the shell of slugs and snails, from a blunt headed slug snake specimen.