The rhinoceros ratsnake (''Gonyosoma boulengeri''), also known commonly as the rhinoceros snake, rhino rat snake, and Vietnamese longnose snake, is a

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), ...

nonvenomous 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 ...

ratsnake Rat snakes are members – along with kingsnakes, milk snakes, vine snakes and indigo snakes – of the subfamily Colubrinae of the family Colubridae. They are medium to large constrictors and are found throughout much of the Northern Hemis ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Colubridae 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. C ...

. The species is found from northern

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

to southern

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 ...

. It has a prominent, distinctive, scaled protrusion on the front of its snout, which has led to its common naming after a

rhinoceros A rhinoceros ( ; ; ; : rhinoceros or rhinoceroses), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates (perissodactyls) in the family (biology), famil ...

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''boulengeri'', is in honor of Belgian-

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

George Albert Boulenger George Albert Boulenger (19 October 1858 – 23 November 1937) was a Belgian-British zoologist who described and gave scientific names to over 2,000 new animal species, chiefly fish, reptiles, and amphibians. Boulenger was also an active botani ...

Geographic range

''G. boulengeri'' is found in northern Vietnam including Tam Dao,''Rhynchophis boulengeri''
. www.schlangenland.de. Retrieved on 2013-01-03. and in southern

. During a 2001 survey, 10 specimens were observed in

Yên Bái Province Yên Bái was a former Provinces of Vietnam, province located in Northwest (Vietnam), Northwest Vietnam. It shares borders with six provinces which are Hà Giang province, Lào Cai province, Lai Châu province, Sơn La province, Phú Thọ provinc ...

, northern Vietnam.Tordoff et al. (May 2001)
A Rapid Biodiversity Survey of Che Tao Commune, Mu Cang Chai District, Yen Bai Province, Vietnam, Hanoi
note those of its reported species which have IUCN Redlist status, and have no such notes for ''Rhynchophis boulengeri'' which was observed in this report.

Description

The adult size of ''G. boulengeri'' is in total length (including tail). Its scale count includes 19 rows of dorsals at midbody.

Natural history

The rhinoceros ratsnake inhabits

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

rainforests 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 ...

at elevations between , particularly valleys with streams. It is generally

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 ...

, and mostly diurnal, hunting small

mice A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

and other

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 ...

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s, and perhaps other

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

prey.

Oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

, its mating season from April to May may produce five to 10 eggs in a

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

. After 60 days' incubation,

hatchling In oviparous biology, a hatchling is a newly hatched fish, amphibian, reptile, or bird. A group of mammals called monotremes lay eggs, and their young are hatchlings as well. Fish Fish hatchlings generally do not receive parental care, similar t ...

s are total length, brownish grey with dark edges on several

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

. As they mature, rhinoceros ratsnakes change color to steel grey at about 12–14 months, then to a bluish green or green adult hue at about 24 months. However, a rare few individuals maintain their steel grey

subadult A juvenile is an individual organism (especially an animal) that has not yet reached its adult form, sexual maturity or size. Juveniles can look very different from the adult form, particularly in colour, and may not fill the same niche as t ...

color and do not pass into ordinarily mature color phase. Studies conducted by Bangor University have suggested that the nasal protrusion is used for mating displays in which the males may 'fence' off rivals. Other studies have found little correlation between the use of the nasal protrusion and courtship displays, which may suggest the true function is still unknown.

References

External links

*Captive care of rhino ratsnakes (''Rhynchophis boulengeri'' ) from Adam Wilford of AC Snakes, United Kingdo

*Sacha Korell's Natural ''Elaphe'' Collection image gallery for Vietnamese Longnose Snake (''Rhynchophis boulengeri''

*Image: "A rare rhino rat snake (''Rhynchophis boulengeri'' ) emerges from its shell at ZSL London Zoo". Telegraph.co.u

{{Taxonbar, from=Q44208311 Gonyosoma Reptiles described in 1897 Reptiles of Vietnam Reptiles of China Snakes of China Snakes of Vietnam Snakes of Asia Taxa named by François Mocquard