Reptiles and Amphibians of Thailand

Thailand's Snakes, Lizards, Turtles, and Frogs

Malayan Slug Snake

Asthenodipsas malaccana

This species is found in Thailand, but not within Bangkok itself
Malayan Slug-eating Snake Asthenodipsas malaccanus thailand Bang Lang NP
Malayan Slug Snake in peninsular Malaysia (© Evan Quah)

English name: Malayan Slug Snake (aka “Malayan Dark-necked Slug Snake”, “Malayan Slug-eating Snake”)
Scientific name: Asthenodipsas malaccana (formerly Asthenodipsas malaccanus, Pareas malaccanus)
Thai name: งูกินทากมลายู (Ngu Gin Thaag Malayu)

Description: To 45cm. A small snake with a streamlined head horizontally broader than the vertically compressed body. The head is white, gray, or black and is followed by a long black blotch covering both sides of the neck. Body is gray to black with white-to-silver dorsolateral blotches, sometimes with a dorsal line of the same color.

Relevant scale counts: 7-8 supralabial scales. The dorsal row of scales forms a weak keel all the way down the body’s length.

Similar Species: Smooth Slug Snake lacks the dorsal keel and strikingly white head with black neck blotches.
Blunt-headed Slug Snake has a shorter, broader head, does not have the white head and black neck, and has a more slender body.

Range: Southern Thailand, peninsular Malaysia and Sumatra.

Habitat: Mature forest.

Place in the ecosystem: The Malayan Slug Snake and its close relative the Bornean Dark-necked Slug Snake are unique among slug snakes in that they appear to feed exclusively on slugs and not snails. This could be why unlike other slug snake species they show no asymmetry in its jaw and tooth structure. This snake may be eaten by larger snakes, nocturnal birds and carnivorous mammals such as civets.

Danger to humans: The Malayan Slug Snake is no danger to humans.

Conservation status and threats: Conservation status is unknown, though its range in Thailand and peninsular Malaysia appears limited with specimens only reported from a few localities.

Interesting facts: For some time researchers noted that Malayan Slug Snakes from the mainland and Sumatra appeared different from what were called Malayan Slug Snakes on the island of Borneo. In January 2020 Evan Quah published a paper showing that these were in fact separate species. Unlike the Malayan Slug Snake, the Bornean Dark-necked Slug Snake has a tan or brown body with dark crossbars on the sides and a strong vertebral ridge. It is only found on the island of Boreno.

References:
Reptile Database: Asthenodipsas malaccanus
A taxonomic revision of Asthenodipsas malaccana with a description of a new species from Borneo
Distribution and natural history notes on some poorly known frogs and snakes from Peninsular Malaysia
A taxonomic reappraisal of the Smooth Slug Snake Asthenodipsas laevis
Right-handed snakes: convergent evolution of asymmetry for functional specialization
Serpents of Thailand

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