Saturday 15 June
Mexican horned pitviper (Ophryacus undulatus)
Mexican horned pitviper fact file
- Find out more
- Print factsheet
Mexican horned pitviper description
The Mexican horned pitviper (Ophryacus undulatus) is a rare, venomous snake about which very little is known. It can be easily distinguished from most other vipers by the raised scales above its eyes, giving the appearance of horns (3).
The Mexican horned pitviper varies in colour throughout its range, from grey to green on the upperparts (3), typically with yellowish underparts (2). There is an irregular, darker zigzag pattern along its back (2) (3).
Like other vipers (species in the Viperidae family), the Mexican horned pitviper has a triangular-shaped head, vertical pupils, and long, pointed, curved fangs. The fangs are hinged, allowing them to lie flat against the roof of the mouth when the mouth is closed, and then rotate forward when the viper is ready to strike. Venom, produced in glands at the back of the head, flows through the fangs into the prey (4).
Pitvipers are named after the pair of small pits situated between the eye and nostril. These pits are sensitive to heat, helping the Mexican horned pitviper to locate warm-blooded prey (4).Top
Mexican horned pitviper biology
The Mexican horned pitviper hunts rodents (3), using the heat-sensitive organs on its head to locate these warm-blooded mammals (4). It also takes small lizards (3). When ready to strike, the Mexican horned pitviper erects its fangs and thrusts them into the prey (4). The venom that flows through the fangs into the prey affects the blood, causing the prey to die quickly of internal bleeding and haemorrhaging (5).
Unlike many other reptiles, which lay eggs, the Mexican horned pitviper bears live young. The female Mexican horned pitviper typically gives birth to between 6 and 13 young at a time (3).Top
Mexican horned pitviper range
As its name suggests, the Mexican horned pitviper is found only in Mexico, where it is present in isolated populations in the southern parts of the Sierra Madre Oriental and the Sierra Madre del Sur mountain ranges. It has been reported in the states of Hidalgo, Veracruz, Puebla, Oaxaca and Guerrero (1).Top
Mexican horned pitviper habitatTop
Mexican horned pitviper status
The Mexican horned pitviper is classified as Vulnerable (VU) on the IUCN Red List (1).Top
Mexican horned pitviper threats
The primary threat to the Mexican horned pitviper is the loss of its habitat to agriculture and logging (1) (6). Pine-oak forest once covered around 21 percent of Mexico, but now covers no more than 8 percent (6), and the remaining habitat of the Mexican horned pitviper is severely fragmented (1).
Like many snakes, the Mexican horned pitviper suffers from persecution, and is often killed by locals if encountered (1).Top
Mexican horned pitviper conservation
Although there are no specific conservation efforts in place for the Mexican horned pitviper, it is present in at least three protected areas (1), and several conservation organisations are working to preserve Mexico’s pine-oak forests (6). For example, Pronatura Noreste works in the Sierra Madre Occidental and Sierra Madre Oriental to conserve and promote the sustainable use of natural resources (6) (7). Such efforts will likely benefit this highly threatened snake.Top
Find out more
Learn more about conservation in Mexico:
The Nature Conservancy:
Fondo Mexicano para la Conservación de la Naturaleza:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Cloud forest
- A tropical mountain forest, with a high incidence of cloud cover throughout the year.
- Organs that make and secrete substances used by the body.
IUCN Red List (June, 2011)
- Villela, O.F., Mendoza, F., Hernandez, E., Mancilla, M., Godinez, E. and Mayer, I.G. (1992) Ophryacus undulatus in the Mexican state of Hidalgo. The Texas Journal of Science, 44: 2.
- O’Shea, M. (2008) Venomous Snakes of the World. New Holland Publishers, London.
- Ernst, C.H. and Ernst, E.M. (2011) Venomous Reptiles of the United States, Canada and Northern Mexico. The Johns Hopkins University Press, Baltimore, Maryland.
- Campbell, J.A. and Lamar, W.W. (1989) The Venomous Reptiles of Latin America. Comstock Publishing Associates, Ithaca and London.
Conservation International: Biodiversity Hotspots – Madrean Pine-Oak Woodlands (June, 2011)
Pronatura Noreste (June, 2011)
More »Related species
Play the Team WILD game
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.