''Ahaetulla nasuta'', also known as Sri Lankan green vine snake and long-nosed whip snake, is a venomous, slender green tree

snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

Distribution

Due to longstanding confusion over the taxonomy of ''A. nasuta'', the species was once thought to have a large range from Sri Lanka to peninsular India, including the Western Ghats, along with a disjunct population in

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

. However, a 2020 phylogenetic study found ''A. nasuta'' to actually comprise a species complex, with the "true" ''A. nasuta'' (from which the species was originally described) being restricted to the wet zone of Sri Lanka (including the Sri Lanka lowland and

montane rainforests Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

). 4 populations from the Western Ghats of India that were formerly grouped with ''A. nasuta'' were split into the species '' A. borealis'', '' A. farnsworthi'', '' A. isabellina'', and '' A. malabarica''. The large-bodied form from lowland peninsular India (and possibly the

dry zone An alcohol-free zone is a geographic area, location or establishment where the public consumption and sale of alcoholic beverages is prohibited. Alcohol-free zones have been established in some areas to address problems with drinking- and binge dr ...

of the northern portion of Sri Lanka), which was also formerly grouped with ''A. nasuta'', was found to actually be '' A. oxyrhyncha'', and is actually more closely allied with '' A. pulverulenta'' and '' A. sahyadrensis'' than ''A. nasuta''. Finally, the disjunct population in Southeast Asia was assigned to an as-of-yet undescribed species, tentatively referred to as ''Ahaetulla'' cf. ''fusca'', and is a sister species to '' Ahaetulla laudankia''. Ahaetulla nasuta

Description

Common vine snakes are diurnal, arboreal, and mildly venomous. They normally feed on

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

s and

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s using their binocular vision to hunt. They are slow moving, relying on camouflaging themselves as vines in foliage. They expand their bodies when disturbed to show a black and white scale marking. Also, they may open their mouths in a threat display and point their heads in the direction of the perceived threat. They are the only species of snake with horizontal pupils, compared to the normal vertical slit pupils found in many species of viper. The species is

viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the m ...

, giving birth to young that grow within the body of the mother, enclosed within the egg membrane. They may be capable of delayed

fertilization Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

; (

parthenogenesis Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

is rare but not unknown in snakes) as a female in the London zoo kept in isolation from August, 1885 gave birth in August, 1888.

Taxonomic description

The species name ''Ahaetulla'' in Sinhala means 'eye plucker'. It earned this name, and similar ones in Tamil and Indian vernaculars, due to the mistaken belief that it strikes at the eyes. The following description with diagnostic characters is from Boulenger (1890): Formerly treated as a subspecies ''Ahaetulla nasuta anomala'' is now regarded as a distinct species, '' Ahaetulla anomala''.

Habitat

Found in low bushes, shrubs and trees in lowland forest terrain at elevations up to about 1000 metres, particularly near streams and often found near human settlements.

Venom and its effects

The ingredients of the venom are unknown. The venom is moderately potent and can cause swelling, pain, bruising, numbness and other local symptoms, which will subside within three days. Bites close to the head, eyes and other vital areas could be severe. “Ahaetulla nasuta” at WCH Clinical Toxinology Resources. Accessed on 9.1.2014 at http://www.toxinology.com/fusebox.cfm?fuseaction=main.snakes.display&id=SN0004

Vernacular names

The Sinhala name "Aheatulla" or "eye-plucker" forms the taxonic species name. In

Tamil Tamil may refer to: * Tamils, an ethnic group native to India and some other parts of Asia ** Sri Lankan Tamils, Tamil people native to Sri Lanka also called ilankai tamils **Tamil Malaysians, Tamil people native to Malaysia * Tamil language, nati ...

, it is known as pachai paambu. In

Kannada Kannada (; ಕನ್ನಡ, ), originally romanised Canarese, is a Dravidian language spoken predominantly by the people of Karnataka in southwestern India, with minorities in all neighbouring states. It has around 47 million native s ...

, it is known as Hasiru Haavu. * Sinhala: ඇහැටුල්ලා (Pronounced: Aheatulla) * Tamil: பச்சை பாம்பு * Kannada: ಹಸಿರು ಹಾವು * Marathi: हरणटोळ (Pronounced: harantol)

Notes

References

* Lacepède, B. G. E. 1789 Histoire Naturelle des Quadrupèdes Ovipares et de Serpens. Vol.2. lmprimerie du Roi, Hôtel de Thou, Paris, 671 pp. * Wall, F. 1908 Remarks on some recently acquired snakes. J. Bombay N. H. S. xviii: 778-784 * Wall 1908 A new color variety of the common green whip-snake (''Dryophis mycterizans''). J. Bombay N. H. S. xviii: 919 * Wall, F. 1910 Remarks on the varieties and distribution of the common Green Whip Snake (''Dryophis mycterizans''). J. Bombay nat. Hist. Soc. 20: 229 * Wall 1910 Varieties of the common Green Whip Snake (''Dryophis mycterizans''). J. Bombay nat. Hist. Soc. 20: 524 {{Taxonbar, from=Q619087 nasuta Snakes of Asia Reptiles of Sri Lanka Endemic fauna of Sri Lanka Reptiles described in 1789 Taxa named by Bernard Germain de Lacépède