Vipers are venomous snakes found worldwide except in Antarctica, Australia, and a few other regions. They are characterized by distinct loreal pits between the eyes and nostrils. The two main types are pit vipers, which have loreal pits, and pitless vipers. Two common species in India are Russell's viper and saw-scaled viper. Russell's viper has a thick body with V-shaped marks on its head and three rows of black patches on its back. The saw-scaled viper has a stocky body with a cross mark on its head and zigzag pattern on its back. Both species are nocturnal and lay eggs.

2. INTRODUCTION
• They are found all over the world (India ,Sri lank ,Myanmar,Pakistan
,China,Nepal,Bangladesh,Thaiwan,Thailand and Indonesia) except in Antartica ,Australia, New-
zeland,Ireland , Madagascar, Hawai.
• In India. is abundant in Punjab
• Vipers are highly venomous, medium sized or large sized and solenoglyphous(back fanged) snakes.
• Head is broad , flat and triangular covered by small and keeled scales
• Pupil is vertically elliptical, neck is narrow and tail is blunt.
• Some species have characteristics markings or patches on the back
• The name “viper” denotes the ovoviviparous habit of the snake (vivus-living,parere-to beget)
• Vipers are characterized by a distinct pit in loreum (the region between eye and nostril) on each sides.it is
called loreal pit
• Based on this features vipers are 2 types
1.Pit- vipers
2.pitless vipers

3. Pitless vipers
• There are 42 odd species of pit less vipers, 7 are found in India
• The commonest S.indian forms are Russell’s viper (chain viper or daboia) and saw scalled viper (echis or
phoosa)
Pit-vipers
• Pit vipers have a pair of loreal pits in between eyes and nostrils. Most of them have small scales ,but
some have shields on the head.

5. Russell’s viper(Vipera russellii)
Identifying features
 Thick and rough –scaled body ,neck is narrow and short and blunt tail
 Flat, broad and triangular head ,covered by small keeled scales
 A characteristics V-shaped mark and some spots on the head
 Vertically elliptical pupil
 3 longitudinal rows or chains of black patches or rings on the back
 Large and wide nostrils ,wider than those of any other Indian snakes
 Broad belly plates (ventral )and sub –caudals
 Light brown or yellow back and white and speckled belly with scattered spots
 Solenoglyphous fangs

6. Habitat
 The snake is mostly found in open,grassy or bushy areas but may also be found in second growth
forest
 It is most common in Plaines , coastal low lands and hills of suitable habitate
 Generally not found at altitude, but has reported as far up as 2300 -3000 m, humid environment such
as marshes ,swamps and rain forests are avoided
Behavior
 Mainly nocturnal, during cool whether it will alter its behavior and become more active during day
 Adult are reported to be slow and sluggish
 Raise 1st third of body and produce a hiss that is supposedly louder than that of any other snakes

7. Reproduction
Viper is ovoviviparous , mating generally occur early in the year
although gravid female may be found at any time .The gestation period is more than
6 months . Young's are produced from may to November , but mostly in June and
July.
Prey
it feeds a primarily on rodents especially murid species .it will all so eat rats ,mice
, shrews,squirrels,land scabs ,scorpions and other arthropods. Juveniles are
cannabalistic and all so will eat other snake s ,lizards etc…

8. Venom
Experiment have shown these snakes are capable of making decision on how
much venom inject depending on the circumstances.importants determinant of
venom expenditure is size of the snake (large specimen being capable of delivering
much more venom).
Venom of viper is haemotoxic in action . The symptoms of viper bite are local as
well as constitutional .the local symptoms include swelling stinging pain and
bruising of the bitten part. Constituitional symptoms include rapid collapse and
failure of heart ,if a lethal dose of venom is injected.

10. Saw-scaled viper (Echis carinatus)
Identifying feature
 Stocky body,covered by rough and strongly keeled scales
 Head wider than neck and trunk
 A distinct cross or lance mark on the top of the head and zig –zag pattern on the back
 A pale ,wavy white line along each flank of the back
 Short and stubby tail
 Back is dull colored and the under side is white with brown speckles

11. Geographical range
Ehis carinatus is endemic to Asia ,found an a range of different substrates including sand , rock ,
soft soil and in scrub landsc
Behavior
Echis carinatus side winding. This species is mostly crepuscular and nocturnal ,although there have
been reports of activity during day light hours .during the day time they hide in all kinds of places
such as deep mammal burrow, rock fissures they are mostly active after rain or on a humid night.

12. PITLESS VIPERS
Vipera russellii (Russell’s viper or Daboia)

13. Vipera lebetina (levantine viper)

14. Echis carinatus (saw – scaled viper)

15. Pit - viper
Agkistrodon himalayanus (Himalayan pit viprer)

16. Agkistrodon hypnale (hump-nosed pit viper)

17. Trimeresurus macrolepis (green pit viper)

18. Trimeresurus malabaricus (malabar rock pit viper)

19. Trimeresurus strigatus (Horse – shoe pit viper)

20. Trimeresurus gramineus (Bamboo pit viper)

21. Trimeresurus monticola (Blotched pit viper)

22. Trimeresurus jerdoni (Jerdon’s pit viper)

23. Trimeresurus stejnegeri (stenjnerger’s pit viper)

24. Trimeresurus popeorum (Pope’s green pit viper)

25. Trimersurus mucrosquamatus(Brown spotted pit viper)