Snakes can be identified as poisonous or non-poisonous based on several physical features: 1. Poisonous snakes have 1-2 puncture wounds from fangs, continuous blood flow, and round/cylindrical tails. Non-poisonous snakes have many puncture wounds that stop bleeding. 2. Poisonous snakes have broad ventral scales extending across the belly, while non-poisonous snakes have narrow ventral scales. 3. Poisonous snakes like cobras and kraits have small scales on the head and features like loreal pits between the eyes and nose.

1. IDENTIFICATION OF POISONOUS SNAKES
INTRODUCTION:
 Snakes are cylindrical, long, limbless, cold-blooded reptiles.
 There are about 3500 species of snakes known amongst which about 350
species are venomous.
 In India, about 216 species are found and amongst them, about 52 are
poisonous.
 Most of the snakes are non-poisonous. Identification of poisonous or non-
poisonous snakes is important because sometimes the bite of a non-
poisonous snake may lead to death out of fear.
The poisonous snakes are identified by a careful examination of the following
points.
 Nature of the snake bite
 Nature of the tail
 Nature of the ventrals
 Nature of the scales on the head
 Nature of the sub-caudal scales
 Nature of vertebrals
FROM THE NATURE OF THE SNAKE BITE:
 When a poisonous snake bites, there will be 1 or 2 punctures on the skin
of the victim (the punctures are
made by fangs).

2.  If a non-poisonous snake
bites, many punctures are usually
made on the skin by the maxillary
teeth of upper jaw.
 If a poisonous snake bites
there will be a continuous flow of
blood from the wound. The venom
prevents the clotting of the blood
 It a non-poisonous snake bites
flow of blood is stopped after
sometimes owing to the clotting of
blood.
FROM THE NATURE OF THE
TAIL
 The tail of a snake should be observed first.
If the tail of a snake is flat, laterally compressed and oar-shaped
(adaptation to swimming in water), it is a sea snake.
All sea snakes are poisonous. The body is covered by small scales dorsally.
Eg: Hydrophis, Enhydrina.
 If the tail ends bluntly, it is nonpoisonous.
 If the tail is round or cylindrical and pointed, it may be poisonous or non-
poisonous. It may be terrestrial or fresh water.
FROM THE NATURE OF THE VENTRALS
 If the tail is round and not compressed, then examine the ventrals (scales
on the ventral side of the trunk).
 If the ventrals are small and narrow, it is a non-poisonous snake.

3.  In some non-poisonous snakes like Python, the ventrals are fairly broad,
but do not extend completely across the belly. On either side of Ventra is,
small scales are present.
 If the ventrals are broad extending completely across the belly, it may be
poisonous or a non-poisonous snake.
FROM THE NATURE OF THE SCALES OR SHIELDS ON THE HEAD
 If the tail is round and the ventrals are broad, then examine the head of
the snake.
 If the head is triangular and covered with small scales and not with
shields, it is a viper.
 All vipers are poisonous. Vipers are of two types.
1. Pit vipers 2. Pitless vipers.
1. Pit vipers
 If there is a loreal pit between the eye and nostril, the snake is a pit viper
(pit organ is a thermoreceptor)
Eg: Trimeresurus (lachesis)
 Some pit vipers possess shields on their heads. Eg : Ancistrodon
2. Pitless vipers.

4.  If there is no loreal pit between the eye and the nostril, it is a pitless viper.
 If the head is covered with small scales and there is no loreal pit, then the
sub-caudals are to be examined.
 If sub-caudals are in two rows and there is no loreal pit, then the snake
is Russels viper.
 It is a pitiess viper with a large body and bears 3 rows of large diamond-
shaped spots on the dorsal side of the body.
FROM THE NATURE OF THE VERTEBRATE
 If the head is covered with shields, not with small scales it may be
poisonous or nonpoisonous.
 Then examine the vertebrals (scales present along the mid-dorsal line on
the back).
 If the vertebrals are large and hexagonal, it is a krait and it is highly
poisonous.
 In addition to the enlarged vertebrals, the krait is characterized by the
presence of only 4 infra-labials of which the fourth one is the largest
(infra-labials are the shields forming the margin of the lower jaw).
 The sub-caudals are present in a single row in krait.
Eg ;Bungarus.

5.  If the vertebrals are not large, then examine the supra-labial shields (the
shields forming the margin of the upper jaw).
 If the third supra-labial shield touches the nasal shield and the eye, it is
either a cobra or a coral snake.
 Both cobras and coral snakes are poisonous.
Difference between poisonous and non-poisonous snakes
Features Venomous/poisonous snakes Non-venomous/non-poisonous snakes
Physical features Stout, dull color Slender, brightly colored
Saliva Contains toxic peptides and
enzymes
Non-toxic
Tail Compressed Rounded
Ventral (belly) scales
Broad and always extends
across the entire width of the
belly
Small/ moderately large, never extends
across the belly
Vertebral (back)
scales
Enlarged as in Krait Not so
Head scales
Usually smaller. It could be
larger also and when larger,
will possess special features
such as:
Usually larger and without any special
features
• A pit between eye and nose
as in pit viper

6. • A third supra-labial scale
touching the eye and nasal
shield, as in cobra, king cobra
• A large fourth Infralabial
shield, as in krait
Teeth
Upper jaw has a pair of teeth
modified into fangs that are
grooved (Cobra) or
channelised (viper)
All teeth are uniform and small in size and
there are no fangs.
Usually there are 4 longitudinal rows of
teeth in upper jaw and 2 rows in lower jaw.
Bite marks
Usually two (fang marks) More than two
Nocturnal habit
Usually nocturnal Not nocturnal
Biting mechanism:
The biting apparatus taking part in the biting process are
1. Poison glands
2. Poison ducts
3. Poison teeth or Fangs.
 Poisonous snakes inject venom using modified salivary glands.
 During envenomation (the bite that injects venom or poison), the venom
passes from the venom gland through a duct into the snake's fangs, and
finally into its prey.
 Snakes consisting Poison-Apparatus By the contraction of digastric
muscles in Poison-Apparatus in snake the mouth is opened.
 Then the lower jaw moves forward.
 The sphenopterygoid muscles contract which results in the forward
movement of pterygoid which brings rotation of maxilla, results the fang
is raised and becomes directed forward.
 The contraction of the digastric muscle will squeeze of poison gland.
 This makes the poison to come out of the poison gland and flows into the
enemies body.

7. On the basis of structure and position, the fangs are of the following types:
1) Proteroglyphous type: The fangs are comparatively small and they
are present in front of the maxillae. The fang has a groove all along its
anterior face.
Examples : Cobra, Krait, Sea snakes and Coral snakes.
2) Stenoglyphous type: The fangs are movable and turned inside.
Poison canal runs through the fang and opens at the tip.
Examples: Vipers and Rattle snakes.
3) Opisthoglyphous type: The fangs are small and lie at the back
portion of maxillae. The fang has a groove along its posterior face.
Examples : Some colubrid snake (African tree snakes)
4) Aglyphous type: Aglyphous dentition is present in the non-
poisonous snakes.
Toxicity of Snake Bite
The snake poison or snake venom is useful in killing the prey and in
defense.

8. The poison is a pale yellow colored fluid made up of a mixture of two
major types of powerful enzymes. They are
A. Neurotoxin:
It affects the central nervous system; especially the motor nerves and
causes cardiac and respiratory failure. It is present in the poison of
cobra (cobradin), Kraits, sea snakes etc. (except vipers).
B. Haemotoxin:
It includes cardio toxins and Haemorrhagins. It is present in the
poison of vipers (viperidin).
Cardiotoxins: Affects the heart’
Haemorrhagins: It affects cardiovascular system. They contain
enzymes like proteolysins, lecithinases, phosphoridases etc.
Proteolysins and Lecithinases destroy the endothelium of blood
vessels and cause profuse bleeding.
Phosphoridases produce haemolysis leading to cardiac and
circulatory failures.
Do's and Don'ts of Treating Snake Bite
Symptoms usually manifest soon after a snake bite, so observing the
victim is extremely important. If no symptoms have occurred within
half an hour of the bite then indications would be that it was not a
venomous snake, it failed to inject any venom or the snake was very
old and had little or no venom left.
Do
 Try to identify the snake; colour, size, shape of head, attacking
method are all useful
 Loosen the Victim’s clothing and, if necessary, move them in to
the shade
 Keep the victim calm and still; movement will increase blood
flow and transport the venom to the heart much faster
 Immobilize the limb but do NOT restrict blood flow unless you
are certain the bite was from a snake that delivers neurotoxic
venom
 Clean and dress the wound being careful not to apply pressure
and cause bruising
 Get the victim to a hospital as soon as possible
Do Not

9. While there can be differences of opinion as to what we should do for
snake bites the consensus of opinion as to what not to do is
reasonably consistent:
 Allow the victim to exercise or stress themselves
 Cut the bite or attempt to suck the venom out
 Give the victim anything to eat or drink especially alcohol
 Use potassium permanganate crystals or solution near or on
the bite wound
 Use soapy water round the bite wound
 Leave pressure bandages on too long
 Leave the victim alone
 Apply ice to the wound
 Soak the affected limb in any solutions