PARAGUAYAN WILDLIFE HOME
REPTILES HOME
FAMILY VIPERIDAE
There are about 290 species of vipers which occur throughout the world.  Other than 2 species of coral snakes, all of the poisonous snakes of North America are vipers.  They typically possess thick bodies and heads which are roughly triangular.  They possess a pair of curved fangs in their upper jaws.  Most are nocturnal and bear live young (Behler, 1989).  The true vipers of the subfamily Viperinae are limited to the Old World. 

     Some pythons can detect heat using sensors in the depressions in labial scales.  Vipers of the subfamily crotalinae possess pits in the front of their heads which lead to more than 7,000 sensory neurons (Bauchot, 1994).  Between their eyes and nostrils, these are sensitive to heat and allow them to track warm-blooded animals.   Pit vipers have the most well developed sense of heat and some species can deted changes as small as 0.001 degree Celsius.   Blind rattlesnakes are about as accurate in striking prey as those that can see (Mattison, 1995).

Bothrops

     This genus is widely distributed throughout South America and the range of B. ammodytoides in Argentina qualifies it as the snake found furthest south.  Most South American fatalities due to snake bites are caused by snakes of this genus (Mattison, 1995).

 Bothrops alternatus

Bothrops alternatus

Bothrops jarraraca

Bothrops jarraraca

Bothrops jarraracussu

Bothrops jarraracussu

Bothrops jarraracussu
Bothrops moojeni

Bothrops moojeni

Bothrops neuwiedi

Bothrops neuwiedi

   
Crotalus durissus

Crotalus durissus

Crotalus durissus
Crotalus durissus