Selasa, 26 Mei 2015

Common names: hognosed pitvipers.

Porthidium is a genus of venomous pitvipers found in Mexico and southward to northern South America. The name is derived from the Greek word portheo and the suffix -idus, which mean "destroy" and "having the nature of", apparently a reference to the venom. Seven species are currently recognized. The snakes of the genus Hypnale in southern India and Sri Lanka look quite similar to those of this genus, possibly an example of convergent evolution.

Description


Porthidium

This is a group of small species, adults ranging in size from 55 centimetres (22 in) (P. dunni and P. yucatanicum) to 75 centimetres (30 in) in total length (P. lansbergii and P. ophryomegas). In addition, the body shape ranges from relatively slender (P. ophryomegas) to relatively stout (P. nasutum). All have a sharply defined canthus rostralis and a rostral scale that is higher than it is broad. The tip of the snout may be slightly to moderately elevated (P. hespere, P. lansbergii, P. ophryomegas and P. volcanicum), strongly elevated (P. dunni and P. yucatanicum), or not elevated at all. All species have a color pattern that usually consists of a brown or gray ground color, overlaid with a series of dark paraventral blotches that are separated by a pale and narrow vertebral stripe. The blotches are square, rectangular, or triangular in shape. In some species, the color pattern is determined by the sex.

Geographic range


Porthidium

Found in Mexico (Colima, Oaxaca and Chiapas on the Pacific side, the Yucatán Peninsula on the Atlantic side) southward through Central America to northern South America (Ecuador in the Pacific lowlands, northern Venezuela in the Atlantic lowlands).

Species


Porthidium

*) Not including the nominate subspecies.
T) Type species.

See also


Porthidium
  • List of crotaline species and subspecies
  • Crotalinae by common name
  • Crotalinae by taxonomic synonyms
  • Snakebite

References


Porthidium

External links


Porthidium
  • Porthidium at the Reptarium.cz Reptile Database. Accessed 15 September 2007.
  • Porthidium at Herpbreeder.com. Accessed 15 September 2007.

Porthidium
 
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