''Ahaetulla,'' commonly referred to as Asian vine snakes or Asian whip snakes, is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

colubrid Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. Colu ...

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

s distributed throughout tropical

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. They are considered by some scientists to be mildly

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

and are what is commonly termed as 'rear-fanged' or more appropriately, opisthoglyphous, meaning their enlarged

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

or fangs, intended to aid in venom delivery, are located in the back of the upper

jaw The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth ...

, instead of in the front as they are in

viper Vipers are snakes in the family Viperidae, found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, New Zealand, Ireland, and various other isolated islands. They are venomous and have long (relative to non-vipe ...

s or

cobra COBRA or Cobra, often stylized as CoBrA, was a European avant-garde art group active from 1948 to 1951. The name was coined in 1948 by Christian Dotremont from the initials of the members' home countries' capital cities: Copenhagen (Co), Brussels ...

s. As colubrids, Ahaetulla do not possess a true venom gland or a sophisticated venom delivery system. The Duvernoy's gland of this genus, homologous to the venom gland of true venomous snakes, produces a secretion which, though not well studied, is considered not to be medically significant to humans. Green-colored members of this genus are often referred to as green vine snakes. They are not to be confused with the "green vine snake" '' Oxybelis fulgidus'', which convergently appears very similar but is found in Central and South America.

Etymology

The genus name ''Ahaetulla'' comes from the Sri Lankan Sinhalese words ''ahaetulla/ahata gulla/as gulla'', meaning “eye plucker” or “eye picker”, because of the belief that they pluck out the eyes of humans, as first reported by the Portuguese traveler João Ribeiro in 1685.

Vernacular names

The Sinhala name "" or "eye-plucker" forms the taxonomic genus name. In

Tamil Tamil may refer to: People, culture and language * Tamils, an ethno-linguistic group native to India, Sri Lanka, and some other parts of Asia **Sri Lankan Tamils, Tamil people native to Sri Lanka ** Myanmar or Burmese Tamils, Tamil people of Ind ...

, it is known as , in

Malayalam Malayalam (; , ) is a Dravidian languages, Dravidian language spoken in the Indian state of Kerala and the union territories of Lakshadweep and Puducherry (union territory), Puducherry (Mahé district) by the Malayali people. It is one of ...

it is known as , in Telugu it is known as ', in

Marathi Marathi may refer to: *Marathi people, an Indo-Aryan ethnolinguistic group of Maharashtra, India **Marathi people (Uttar Pradesh), the Marathi people in the Indian state of Uttar Pradesh *Marathi language, the Indo-Aryan language spoken by the Mar ...

, it is known as , and in

Kannada Kannada () is a Dravidian language spoken predominantly in the state of Karnataka in southwestern India, and spoken by a minority of the population in all neighbouring states. It has 44 million native speakers, and is additionally a ...

it is known as . There are dozens of other vernacular names for this snake genus within its range. * Sinhala: ඇහැටුල්ලා (Pronounced: Aheatulla) * Telugu: పచ్చారిపాము; పసరికపాము * Bengali: লাউডগা. * Odia: ଲାଉଡଙ୍କିଆ * Kannada: ಹಸಿರು ಹಾವು, ಹಸಿರು ಬಳ್ಳಿ ಹಾವು. * Gujarati: લીલવણ, માળણ. * Marathi हरणटोळ, शेलाटी * Tamil: பச்சை பாம்பு * Malayalam: പച്ചില പാമ്പ്,കൺകൊത്തി

Taxonomy

Their closest relative is the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus '' Proahaetulla'', which ''Ahaetulla'' diverged from an estimated 26.57 million years ago, during the mid-

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

. From here, the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

containing ''Proahaetulla'' and ''Ahaetulla'' is a

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to the genus '' Dryophiops'', and the clade containing all three of these genera is a sister group to the clade containing the bronzeback snakes ('' Dendrelaphis'') and flying snakes ('' Chrysopelea''). These relationships can be shown in the

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below, with possible

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

''Ahaetulla'' species noted: In 2020, an analysis of '' Ahaetulla nasuta, Ahaetulla dispar'', and '' Ahaetulla pulverulenta'' throughout their range found them to represent

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

es containing several undescribed or formerly synonymized species, leading to the description of '' A. borealis'', '' A. farnsworthi'', '' A. malabarica'', '' A. travancorica'', and '' A. sahyadrensis'', as well as the resurrection of '' A. oxyrhyncha'' and '' A. isabellina''. '' Ahaetulla nasuta'' and '' Ahaetulla pulverulenta'', formerly considered to have much wider ranges, are now considered

endemic Endemism is the state of a species being found only 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 foun ...

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

Species

The

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

of vine snakes is not well-documented, and literature varies widely, but there are 20 currently accepted

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

in the genus ''Ahaetulla'': *'' Ahaetulla anomala'' ( Annandale, 1906) - Variable colored vine snake (possibly

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

with ''A. oxyrhyncha'') *'' Ahaetulla borealis'' Mallik, Srikanthan, Pal, Princia D'Souza, Shanker & Ganesh, 2020 - Northern Western Ghats vine snake *'' Ahaetulla dispar'' ( Günther, 1864) - Günther's vine snake * '' Ahaetulla farnsworthi'' Mallik, Srikanthan, Pal, Princia D'Souza, Shanker & Ganesh, 2020 - Farnsworth's vine snake *'' Ahaetulla fasciolata'' (

Fischer Fischer is a German occupational surname, meaning fisherman. The name Fischer is the fourth most common German surname. The English version is Fisher. People with the surname A * Abraham Fischer (1850–1913) South African public official * ...

, 1885) - Speckle-headed whipsnake *'' Ahaetulla flavescens'' (

Wall A wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or serves a decorative purpose. There are various types of walls, including border barriers between countries, brick wal ...

, 1910 - yellow whipsnake *'' Ahaetulla fronticincta'' ( Günther, 1858) - Burmese vine snake *'' Ahaetulla fusca'' ( Duméril, Bibron, & Duméril,1854) - dark whipsnake *'' Ahaetulla isabellina'' (

, 1910) - Wall's vine snake *'' Ahaetulla laudankia'' Deepak, Narayanan, Sarkar, Dutta & Mohapatra, 2019 - Laudankia vine snake * Mirza, Pattekar, Verma, Stuart, Purkayastha, Mohapatra & Patel, 2024 - long-snouted arboreal snake *'' Ahaetulla malabarica'' Mallik, Srikanthan, Pal, Princia D'Souza, Shanker & Ganesh, 2020 - Malabar vine snake *'' Ahaetulla mycterizans'' (

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...

) - Malayan green whipsnake *'' Ahaetulla nasuta'' ( Lacépède, 1789) - Sri Lankan green vine snake *'' Ahaetulla oxyrhyncha'' (

Bell A bell /ˈbɛl/ () is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be m ...

, 1825) - Indian vine snake *'' Ahaetulla perroteti'' ( Duméril & Bibron, 1854) - Nilgiri vine snake *'' Ahaetulla prasina'' ( Boie, 1827) - Oriental whipsnake or Asian vine snake **''Ahaetulla prasina prasina'' ( Boie, 1827) **''Ahaetulla prasina medioxima'' Lazell, 2002 **''Ahaetulla prasina preocularis'' (

Taylor Taylor, Taylors or Taylor's may refer to: People * Taylor (surname) ** List of people with surname Taylor * Taylor (given name), including Tayla and Taylah * Taylor sept, a branch of Scottish clan Cameron * Justice Taylor (disambiguation) ...

, 1922) **''Ahaetulla prasina suluensis'' Gaulke, 1994 *'' Ahaetulla pulverulenta'' ( Duméril & Bibron, 1854) - Brown-speckled whipsnake *'' Ahaetulla rufusoculara'' Lam, Thu, Nguyen, Murphy, & Nguyen, 2021 *'' Ahaetulla sahyadrensis'' Mallik, Srikanthan, Pal, Princia D'Souza, Shanker & Ganesh, 2020 *'' Ahaetulla travancorica'' Mallik, Srikanthan, Pal, Princia D'Souza, Shanker & Ganesh, 2020 - Travancore vine snake Several

undescribed species In taxonomy, an undescribed taxon is a taxon (for example, a species) that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and named. U ...

(including the Southeast Asian ''Ahaetulla'' formerly assigned to ''A. nasuta'') still likely remain in these complexes.

Geographic range

They are found from

and

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and much of

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

. Sri Lanka and the Western Ghats of India are major hotspots of diversity for the genus, with at least 10 of the currently-described species being

to these regions.

Description

All ''Ahaetulla'' species are characterized by thin, elongated bodies, with extremely long tails and a sharply triangular shaped head. They are primarily

green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a com ...

in color, but can vary quite a bit to

yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In t ...

s, oranges,

grey Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...

s, and

brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors Orange (colour), orange and black. In the ...

s. They can have black and/or white patterning, or can be solid in color. Their

eyes An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

are almost unique in the

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

world, having keen binocular

vision Vision, Visions, or The Vision may refer to: Perception Optical perception * Visual perception, the sense of sight * Visual system, the physical mechanism of eyesight * Computer vision, a field dealing with how computers can be made to gain und ...

and keyhole shaped

pupil The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company. It appears black becau ...

s, being similar in this aspect with twig snakes, who also have keyhole shaped pupils.

Behavior

They are primarily diurnal and

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

, living in humid

rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

s. Their diet consists mainly of

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s, but sometimes

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s and

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s are also consumed. '' Ahaetulla fronticincta'', however, feeds exclusively on fish, striking its prey from branches overhanging water. ''Ahaetulla'' venom is not considered to be dangerous to humans, but serves to cause

paralysis Paralysis (: paralyses; also known as plegia) is a loss of Motor skill, motor function in one or more Skeletal muscle, muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory d ...

in their fast moving

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

choices. They are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

In captivity

''Ahaetulla'' species are not yet frequently captive bred, as are many of the more popular snakes in the reptile keeping hobby. They are suitable for more advanced keepers, requiring a humid arboreal habitat and a diet of lizards as they rarely switch to

s. Without proper husbandry, they are prone to health issues and stress.

References

External links

*
Ecology Asia, Snakes of Southeast Asia: Oriental Whip SnakeDr. Zoltan Takacs' Homebase
{{Taxonbar, from=Q602558 Ahaetulla Snakes of India Reptiles of China Reptiles of Sri Lanka Snake genera Taxa named by Johann Heinrich Friedrich Link