The elephant trunk snake or the Javan file snake (''Acrochordus javanicus''), is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of snake in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Acrochordidae The Acrochordidae, commonly known as wart snakes, Java wart snakes, file snakes, elephant trunk snakes, or dogface snakes are a monogeneric family created for the genus ''Acrochordus''. This is a group of basal aquatic snakes found in Australia a ...

, a family which represents a group of primitive non-

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 ...

aquatic

snake Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...

Description

The elephant trunk snake possesses a wide and flat head, and its

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called t ...

s are situated on the top of the

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is ...

. Those head particularities confer to ''A. javanicus'' a certain resemblance with boas. However, its head is only as wide as its body. Females are bigger than males, and the maximum total length (including tail) of an individual is . The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

side of the snake's body is brown, and its ventral side is pale yellow. The skin is baggy and loose giving the impression that it is too big for the animal. The skin is covered with small rough adjacent scales. The skin is also used in the

tannery Tanning may refer to: * Tanning (leather), treating animal skins to produce leather * Sun tanning, using the sun to darken pale skin ** Indoor tanning, the use of artificial light in place of the sun ** Sunless tanning, application of a stain or d ...

industry. The top of the head has no large shields, but instead is covered with very small granular scales. There are no

ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that conta ...

. The body scales are in about 120 rows around the body. The body is stout, and the tail is short and prehensile. Boulenger GA (1893). ''Catalogue of the Snakes in the British Museum (Natural History). Volume I., Containing the Families Typhlopidæ, Glauconiidæ, Boidæ, Ilysiidæ, Uropeltidæ, Xenopeltidæ, and Colubridæ Aglyphæ, part.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 448 pp. + Plates I-XXVIII. (Genus ''Acrochordus'' and species ''A. javanicus'', p. 173). The elephant trunk snake is fully adapted to live underwater so much that its body cannot support its weight out of water and leaving the water can cause it serious injury.

Reproduction

An aquatic snake, the elephant trunk snake is

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

, with the incubation lasting 5 to 6 months and the female expelling 6 to 17 young.

Geographic range

The elephant trunk snake is found in South-East Asia west of the

Wallace Line The Wallace Line or Wallace's Line is a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace and named by English biologist Thomas Henry Huxley that separates the biogeographical realms of Asia and Wallacea, a tran ...

: southern

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

, the west coast of

Peninsular Malaysia Peninsular Malaysia ( ms, Semenanjung Malaysia; Jawi: سمننجڠ مليسيا), or the States of Malaya ( ms, Negeri-negeri Tanah Melayu; Jawi: نڬري-نڬري تانه ملايو), also known as West Malaysia or the Malaysian Peninsula, ...

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...

Borneo Borneo (; id, Kalimantan) is the List of islands by area, third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java Isl ...

(

Kalimantan Kalimantan () is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area. The non-Indonesian parts of Borneo are Brunei and East Malaysia. In Indonesia, "Kalimantan" refers to the whole island of Borneo. In 2019, ...

Sarawak Sarawak (; ) is a state of Malaysia. The largest among the 13 states, with an area almost equal to that of Peninsular Malaysia, Sarawak is located in northwest Borneo Island, and is bordered by the Malaysian state of Sabah to the northeast, ...

), a number of

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

n islands (

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

, Sumatra, and (possibly)

Bali Bali () is a province of Indonesia and the westernmost of the Lesser Sunda Islands. East of Java and west of Lombok, the province includes the island of Bali and a few smaller neighbouring islands, notably Nusa Penida, Nusa Lembongan, and Nu ...

); possibly also in

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailan ...

and

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making it ...

, although the last is discredited by the IUCN.

Habitat

The elephant trunk snake has a coastal living habitat like

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ...

and

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into '' coastal lagoons'' (or ''barrier lagoons' ...

s. But it prefers freshwater and brackish environments.

Feeding

The elephant trunk snake is an ambush predator that preys on

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% ...

es and amphibians. It usually catches its prey by folding its body firmly around the prey. Its loose, baggy skin and its sharp scales find their utility by limiting any risk of escape of the prey, in particular fishes which have bodies covered with a viscous, protective mucus.

Behaviour

The elephant trunk snake is nocturnal. It spends most of its life under water and rarely goes on land. It can stay under water for up to 40 minutes.

Original publication

* Hornstedt CF (1787). "''Beskrifning på en Ny Orm från Java'' ". ''Kongl. Vetenskaps Akademiens Handlingar'' 4: 306-308 + Plate XII. (''Acrochordus javanicus'', new species). (in Latin and Swedish).

References

External links

*http://www.marinespecies.org/aphia.php?p=taxdetails&id=344014 *https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?lin=s&p=has_linkout&id=39267
Javan Filesnakes
at ''Life is Short but Snakes are Long''