Snakes identification

identification of poisonous snakes

1. Identification of Poisonous Snakes B.Ashok Kumar Assistant Professor of Zoology KRK Govt Degree College Addanki-523201 . 9652929696,9441635264 [email protected]

2. Introduction 2700 species of snakes Distributed in tropical & sub tropical regions Absent in New Zealand, Ireland & some isolated oceanic islands Only few sps ., are poisonous The bite venomous snake- two marks of fangs

3. Characters to identify poisonous snakes Tail Ventrals Head Sub caudals Loreal pit Supra labials Hood Infralabials Vertebrals Neck Eyes are to be examined

4. 1.Tail Laterally compressed- sea snake- deadly poisonous cylindrical and tapering- may be poisonous may not be poisonous Then ventrals are to be examined

5. 2.Ventrals(Scales on ventral side) If the ventrals are small- Non venomous If ventrals - broad but not extends fully across belly- non poisonous If the ventrals are broad and extends fully across belly- May be poisonous/ Non poisonous Then the head is to be examined

6. 3.Head & 4.Sub caudals Head –triangular & small scales- true vipers- venomous Loreal pit is absent Two indian pitless vipers

7. If sub caudals –two rows- Vipera russellii Dorsal surface shows- three rows of large black rings(chain viper) If sub caudals – single row- Echis carinata (saw scaled viper)- Dorsals are keeled and serrated-An Arrow mark on the head

8. 5. Loreal Pit If the head – coverd by shields- may be venomous/ Non venomous Then loreal pit is to be observed If loreal pit – in between Nostril & Eye- Pit viper Eg : Ancistodon himalayanus , Lachesis(= Trimerisurus ) strigatus

9. Supra labials & Hood If the 3 rd supra labial touches the eye and nostril- may be cobra/ coral snake- both venomous If hood is present with spectacle mark dorsally- Naja naja - small cuneate plate in between 4 th & 5 th infralabials . Sub caudals in two rows

10. Ophiophagus hannah Largest poisonous snake King cobra Hood with transverse stripes Sub caudals in single row near cloaca, two rows in remaining Feeds on other snakes

11. Coral snakes Hood is absent 3 rd supra labial touches eye and nostril Coral spots on the belly Eg : Callophis , Hemibungarus , Micrurus

12. Infralabials & Vertebrals If there are four infralabials and 4 th is largest- krait In krait mid dorsal scales ( vertebrals ) are large and hexagonal Sub caudals in single row The venom is more toxic than cobra Eg : Bungarus coerruleus - common krait- dorsal surface- bluish/brownish black with white cross streaks Bungarus fasciatus - branded krait- marked with alternate broad black yellowish rings

13. Eye If the pupil of eye – vertical, elliptical (cat like)- venomous If the pupil is round located in the centre - non venomous( exception- coral snake)

14. Snout If snout – pointed/sharp triangle shaped- poisonous If snout- round – non poisonous

15. Neck If neck is constricted- Poisonous If neck is continuous without constriction- non poisonous

16. Teeth Non poisonous- same type(homodont) solid teeth present on upper and lower jaw Poisonous – fangs (maxillary teeth) in upper jaw- canines- grooved/ hollow

17. Rattle If rattle on its tail- poisonous- Rattlesnake If rattle is absent- poisonous/ non poisonous

18. Identification of Poisonous Snakes Sl.No Character Poisonous Snakes Non-Poisonous Snakes 1 Colour Bright coloured Dull except pythons, sand boa, Anaconda 2 Shape of head Long triangular with wide posterior portion Narrow and elongated / round 3 Pupils Cat eyes like with vertical slit like, elongated pupils except in cobras Circular/ round 4 Neck Clear constriction is seen b/w the head and the neck No constriction 5 Hood Present in majority but not conspicuous; highly developed in cobra absent in coral snakes, krait, Russel’s viper.. Absent

19. Identification of Poisonous Snakes Sl.No Character Poisonous Snakes Non-Poisonous Snakes 6 Tail Abruptly tapered and cylindrical but in sea snakes- flat and oar shaped Long and tapering except in burrowing snakes. Short and stumpy in Typlops and Leptotyplops ; very short and rough in Uropeltis ; short and blunt in sand boas 7 Head scales Covered by large plate like shields followed by small ones On head are large but in sand boas head scales are small 8 Dorsal scales Small but spinalscales are larger and hexagonal in kraits Dorsals are larger but spinal scales are not large and hexagonal 9 Ventral scales Usually entire and extend across the belly. In sea snakes ventrals are small and granular as seen on the dorsal side Either across the belly completely ( colubrids )or not ( Boa,Uropeltis )

20. Common Non Poisonous Snakes (1) Python. (2) Ramphotyphlops (common worm or blind snake). (3) Ptyas (the rat snake). (4) Eryx (Boa, double headed snake ‘ Dumuhi ’). (5) Dendrelaphis (Tree snake). (6) Tropidonotus (common pond or grass snake). (7) Dryophis (Green whip snake). (8) Ahaetulla nasuta (vine snake) (9) Eunectes murinus ( green anaconda)-Largest snake in the world-9.5m and 250kgs Python reticulatus - South east Asia- longer than anaconda-10m- but more slender

21. Thank you one and all