Amphiesma stolatum

buff striped keelback
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Colubridae
Subfamily:	Natricinae
Genus:	Amphiesma
Species:	A. stolatum
Binomial name
Amphiesma stolatum (Linnaeus, 1758)
Synonyms
Coluber stolatus Linnaeus, 1758 Elaps bilineatus Schneider, 1801 Natrix stolatus Merrem, 1820 Tropidonotus stolatus Boie, 1827 Rhabdophis stolatus Wall, 1921

The buff striped keelback (Amphiesma stolatum) is a species of nonvenomous colubrid snake found across Asia. It is a typically nonaggressive snake that feeds on frogs and toads. It belongs to the subfamily Natricinae, and is closely related to water snakes and grass snakes. It pretty much resembles an Asian version of the American garter snake. It is quite a common snake but is rarey seen.

Anatomy and morphology

Keeled scales

A small, slender snake, the buff striped keelback is generally olive-brown to gray in colour. The head and the body are of the same colour.

The body of the buff striped keelback is short, and it has a long slender tail which is almost a quarter of its length. Two yellow stripes along the length and to the sides of the spine are the distinctive feature of this snake. These stripes are diffuse at the head and are especially bright on the second half of its body.

The keelback has irregular blackish crossbars on the body. Near the head the crossbars are prominent, whereas on the second half of the snake they become diffuse.

Being identified with a field guide.

Black forked tongue.

The sides of the head are yellow on the head tapers to form a distinctive neck. The nape is red during the breeding season. The chin and throats are white or sometimes orange. There are black vertical markings in front of and behind the large eyes. The eyes have large round pupils with golden flecks on the iris. The forked tongue is black.

The underside is pale cream and has small black spots scattered along both the margins. It has keeled scales.

Morphs

Erythrostictus form with interscale colour visible

There are two distinct colour varieties – a typical variety, found everywhere, with grayish-blue interscale colour. The second variety, erythrostictus, is common mainly in coastal areas and has bright vermillion interscale colour. The interscale colours become visible only when the snake puffs itself up when agitated.

Identifying characteristics

A closeup of head

1. The nasal shield does not touch the second supralabial (upper lip shield).
2. The rostral touches a total of 6 shields. These are two inter-nasals, two nasals and the first supralabial on each side.
3. Presence of single temporal shield.
4. Nineteen rows of costals which are strongly keeled except for the outer row which is perfectly smooth.
5. Presence of stripes.
6. Ventrals 125-161.
7. Anal divided.
8. Subcaudals 50-85.

1. The nasal shield does not touch the second supralabial (upperlip shield).

2. The rostral touches a total of 6 shields. These are two inter-nasals, two nasals and the first supralabial on each side.

3. Presence of single temporal shield.

Size

A buff striped keelback being measured. This one was 52 cm long.

The Buff Striped keelback is usually 40 to 50 cm in length. The maximum length recorded is 90 cm. Females are consistently longer than the males which only rarely reach 620 mm (2 ft) in length.

Distribution

The buff striped keelback is found throughout South and Southeast Asia. Its range extends from Pakistan (Sindh) to Sri Lanka, Philippines, India (including the Andaman Islands), Nepal, Myanmar, Thailand, Laos, Cambodia, Vietnam, Indonesia (Borneo, Sabah), Taiwan and China (Hainan, Hong Kong, Fujian, Jiangxi).

In India, the snake is found up to an altitude of 2,000 feet.

Conservation status

The buff striped keelback is common throughout its range, and is not of international conservation concern.

Ecology and life history

Habitat

The buff striped keelback inhabits river banks, marshy areas and wetlands but is also commonly found in fields, open countrysides and overgrown grassy patches during the monsoon season.^{[citation needed]}

Feeding ecology

The primary diet of adult A. stolatum are small amphibians such as frogs and toads, but they are also known to consume fish, small lizards, and rodents.^{[citation needed]}

Life history

Keelbacks are oviparous. Mating is thought to take place during the aestivation period. Gravid females have been found from April to August and eggs are laid in underground holes from May to September. The snake lays a clutch of 5 to 10 pure white eggs. Females remain with eggs till they hatch. The young snakes are 13 to 17 cm at birth and eat small frogs, tadpoles and insects.^{[citation needed]}

Behavior

The buff striped keelback is diurnal, and although mostly seen on land, it can readily take to water. It has long rear teeth for catching frogs and toads.

The buff striped keelback is nonvenomous and totally harmless. When alarmed, it inflates its body causing the bright interscale colours to be exposed. Sometimes, the snake flattens and narrows its head to form a hood. This behaviour sometimes causes the species to be mistaken by laypersons for a baby cobra.

The snake aestivates during hot weather and appears at the end of summer. It is abundant during the rains. In north India, the striped keelback hibernates 25 to 45 cm under the ground in soil, amongst grass roots.

Local names

A keelback in captivity

• Oriya – Halahalia saapa.
• Bengali – Hele sanp.
• Marathi – Naneti.
• Telugu – Wannapam.
• Tamil – Nirkatan pambu.
• Tulu – Pageley.

Gallery

• 

  A buff-striped keelback (normal form)

• 

  The body of the snake

• 

  The snake being held by the head

• 

  The snake twisting its head while being held.

Bibliography

Closeup of head

• Boulenger, George A. 1890. The Fauna of British India, Including Ceylon and Burma. Reptilia and Batrachia. Taylor & Francis, London, xviii, 541 pp.
• Boulenger, G.A. 1893. Catalogue of the snakes in the British Museum (Nat. Hist.) I. Taylor & Francis, London 448 pp.
• Cox, Merel J.; Van Dijk, Peter Paul; Jarujin Nabhitabhata & Thirakhupt,Kumthorn. 1998. A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand. Ralph Curtis Publishing, 144 pp.
• Das, I. 1999. Biogeography of the amphibians and reptiles of the Andaman and Nicobar Islands, India. In: Ota,H. (ed) Tropical Island herpetofauna. Elsevier, pp. 43-77
• Daniels, J.C. 2002. Book of Indian Reptiles and Amphibians. BNHS. Oxford University Press. Mumbai.
• Linnaeus, C. 1758. Systema Naturae. 10th Edition: 204 pp.
• Wall, Frank. 1921. Ophidia Taprobanica or the Snakes of Ceylon. Colombo Mus. (H. R. Cottle, govt. printer), Colombo. xxii, 581 pages
• Whitaker, Romulus. 2006. Common Indian Snakes - A Field Guide. Revised edition. MacMillan India Ltd. New Delhi.

External links

• Amphiesma stolatum at the Reptarium.cz Reptile Database
• Museum Adolphi Friderici
• Herpetofauna of Myanmar