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UROMASTYX
Dr. Jagdish Kaur
P.G.G.C, Sector 11,
Chandigarh
SCIENTIFIC CLASSIFICATION
 KINGDOM:
ANIMALIA
 PHYLUM :
CHORDATA
 SUB-PHYLUM: VERTEBRATA
 CLASS: REPTILIA
 ORDER: SQUAMATA
 FAMILY: AGAMIDAE
 GENUS: UROMASTYX
HABITAT
 Spiny-Tailed
lizards.
 Herbivorous occasionally eat insects ,
especially when young.
 Spend most of time basking in sun hiding
in underground chambers at daytime /
when danger appears.
 Tend to establish themselves in hilly,
rocky areas with good shelter and
accessible vegetation.
DISCRIPTION
 Size
ranges from 25 cm (10 in) (U.macfadyeni
) to 91 cm (36 in) or more (U. aegyptia)
 Hatchlings or neonates
usually no more
than 7–10 cm (3–4 in) in length
 Like many reptiles, these lizards' colors
change
according
to
the
temperature; during cool weather they
appear dull and dark but the colors become
lighter in warm weather, especially when
basking; the darker pigmentation allows
their skin to absorb sunlight more
effectively.
DISCRIPTION
 Their
spiked tail is muscular and
heavy, and can be swung at an
attacker with great velocity,
usually accompanied by hissing
and an open-mouthed display of
(small) teeth.
 Uromastyxs generally sleep in
their burrows with their tails
closest to the opening, in order
to thwart intruders.
DISTRIBUTION
 Uromastyx
inhabit a range stretching through
most of North and Northeast Africa,
the Middle East, ranging as far east as Iran.
 Species found further east are now placed in
the genus Saara.
 Uromastyx occur at elevations from sea level
to well over 900 m (3,000 ft).
 They are regularly eaten, and sold in produce
markets, by local peoples.
 Uromastyx tend to bask in areas with surface
temperatures of over 50 °C (120 °F)
External characters
•Elongated, depressed and massive lizard.
•Length varies from 23 to 32cms.
•Dorsal side - yellow brown with dark spots
whereas ventral surface - pale in colour.
•Body is divided into three distinct parts:
HEAD: triangular in shape and relatively
small.
It has a pair of small elliptical eyes located
dorso laterally in middle of head.
Behind eye there is present external auditory
meatus.
EXTERNAL CHARACTERS
NECK: Very short
 TRUNK: long and depressed trunk
 It is divided into to regions
 Anterior thick walled thorax and posterior
larger soft abdomen.
 (a)LIMBS: Short pentadactyle and strong.
 (i)FORE LIMBS: THREE PARTS
 Branchium
 Ante branchium
 Manus
 (ii)HIND LIMBS: THREE PARTS:
 Proximal thigh
 Middle shank
 Distal foot or Pus

DIGESTIVE SYSTEM
ALIMENTARY CANAL & DIGESTIVE
GLANDS








ALIMENTARY CANAL
long and convoluted tube
MOUTH: wide slit gap,
bounded by immovable lips.
Lips -covered with horny
scales.
BUCCAL CAVITY:
Narrow anteriorly and wide
posteriorly.
Lined by mucus membrane.
Contains teeth, tongue,
internal nares and buccal
glands.
ALIMENTARY CANAL







PHARYNX:
Present on posterior side
of tongue.
Has many longitudinal
folds.
Near the angles of jaws,
on the roof a pair of
EUSTACHIAN TUBES is
present.
OESOPHAGUS:
Short, narrow, muscular
and straight tube.
Its internal wall has
many longitudinal folds
which allow its
distension during
swallowing of food.
ALIMENTARY CANAL
STOMACH:
 A long ,wide, cylindrical sac like structure,
located on the left side of the body.
 Anterior part -Cardiac stomach
 posterior part Pyloric stomach.
 Held in its position by a fold of peritoneum called
Mesogaster.
 The cardiac stomach - present on left side of liver.
 At the end of the pyloric stomach, the pyloric
sphincter is present.
SMALL INTESTINE:
 A long,narrow and coiled tube. It is divided into
two parts: Duodenum and ileum.

DIGESTIVE SYSTEM
 Duodenum:
the pyloric and forms Ushaped structure with it Duodenum
receives bile and pancreatic ducts.
 Ileum: it is the longest coiled part of
alementary canal, it is shorter then
other lizards.
 LARGE
INTSTINE:
 COLON: Colon is thin walled .
 At the junction of ileum and colon blind
pouch like caecum and ileocolic valve is
present.
LARGE INTESTINE
 RECTUM:
Short tubular, thick walled
structure .
 It stores faeces.
 CLOACA: Divided into three
chamber:
A. Coprodaeum
B. Urodaeum
C. Proctodaeum
 Cloaca reabsorbs excess of water
from faeces and urine.
DIGESTIVE GLANDS
The digestive glands of sand lizard associated
with alimentary canal are as follows:
 (a) Salivary Glands
 (b) Gastric Glands: The gastric glands are
present in the mucous membrane of stomach
which secrete digestive gastric juices.
 (c) LIVER: It is large, brownish red gland
present behind heart between two lungs. It has
three lobes; right, left and dorsal .
A small sac called Gall Bladder is present on the
posterior end of right and left lobe of liver.

DIGESTIVE GLANDS
A cystic duct arising from gall bladder and
hepatic duct from right lobe of liver join to form
first bile duct.
 The second bile duct also arise from left lobe of
liver.
 (d) Pancreas: It is narrow, elongated, band like
gland present on the loop b/w duodenum and
stomach. From posterior end of pancreas
pancreatic duct arises.
 (e) Intestinal Glands: there are many microscopic
glands present in the mucosa of small intestine.

RESPIRATORY SYSTEM
Pulmonary.
 it consists of two main parts; respiratory tract and
respiratory organ.

RESPIRATORY TRACT
long tract connects external nares to lungs.
--External nares are small oval apertures, present on
snout.
--Olfactory sacs or nasal chambers are located on
olfactory capsules of skull.
--Glottis is present at floor of buccopharyngeal cavity.
A.
RESPIRATORY TRACT




--Larynx is small median
chamber supported by a
pair of arytenoid
cartilage and a median
cricoid cartilage.
--Trachea is an elongated
cylindrical tube supported
by complete cartilagenous
rings.
In thorax trachea
bifurcates into two
bronchi .
Bronchi are also
supported by cartilagenous
rings.the bronchii do not
divided into bronchioles.
RESPIRATORY ORGANS
The organs of respiration in
Uromastix are a pair of
LUNGS.
 The lungs are present in
thorax cavity on either side
of heart.
 Elongated ,thin walled,
fusiform, elastic and hollow
sacs of orange colour.
 Symmeterical.
 Inner wall is raised into
network of septa.

RESPIRATORY ORGANS
 In
each lung anterior part is
more
sacculated
and
vascularised.
 Walls of lungs and alveoli have
rich supply of blood.
 Inner
surface is moist due to
mucous secreted by mucous cells
in inner wall.
MECHANISM OF RESPIRATION
In Uromastix, the mechanism of breathing
is efficient than that in frog.
 Performed by the ribs and their intercostal
muscles.
 During
INSPIRATION,
the
external
intercostal muscles contract, so the ribs are
pulled outward and forward.
 Size
of
pleuroperitonial
cavity
increases….lungs expands…air pressure
falls….atmospheric air rushes into lungs.

MECHANISM OF RESPIRATION
 During
EXPIRATION , the internal
intercostal muscles contract to pull
the ribs inwards.
 The lungs contract and air pressure
gets increased.
 Foul air is thrown out.
 In
ALVEOLI , exchange of gases takes
place.
BLOOD VASCULAR
SYSTEM
In Uromastix the blood vascular system is
closed type.
 It consists of three main parts;
 HEART
 ARTERIAL SYSTEM
 VENOUS SYSTEM
 BLOOD

HEART
Heart is consists of three basic chambers; Two
Auricles & One Ventricle and one accessory
chamber i.e. SINOUS VENOSUS.
 It is reddish coloured, triangular, and muscular
organ.
 It has broad base and pointed apex.
 The heart is enclosed in two layered transparent
sac known as PERICARDIUM.

VENTRAL & DORSAL VIEW OF
HEART
INTERNAL STRUCTURE OF
HEART
WORKING OF HEART
The deoxygenated blood is collected in sinus
venosus from the body by three venae cavae.
 Then it contracts to push the blood in right
auricle through the sinus auriclular aperture.
 The left auricle receives the oxygenated blood by
pulmonary veins.
 Now the auricles contract to push the
deoxygenated blood from right auricle to right
side of ventricle.
 During contraction of ventricles some amount of
blood mixed, although large amount remains
seperated by interventricular septum.

WORKING OF HEART
The deoxygenated blood from cavum ventrale is
pumped into pulmonary arch and oxygenated
blood from cavum dorsale is pumped into
systemic arches.
 When ventricle relaxed, the return of blood from
arches is prevented by semilunar valves.

ARTERIAL SYSTEM
The system related with supply of the blood from
the heart to various organs is called ARTERIAL
SYSTEM.
 It consists of;
a. Pulmonary arch
b. Right Systematic arch
c. Left Systematic arch

ARTERIAL SYSTEM
MAIN AORTA
PULMONARY ARCH:
A. It arises from right ventricle side ventrale or
pulmonale of ventricle.
B.
it runs upward and divided into right and left
pulmonary arteries going to right and left lung
respectively.

SYSTEMATIC ARCH
Left systematic arche arises from the medical right
side of ventricles and curves to the left. The
right systematic arises from left side of ventricle
and curve to the right.
VENOUS SYSTEM
The system related with collection of blood from
various parts of the body in heart is called
VENOUS SYSTEM.
 It consists of;
A. Pulmonary vein
B. Two precavals
C. Post caval
D. Renal portal system
E. Hepatic portal system

VENOUS SYSTEM
BLOOD
 The
sand lizard is cold-blooded
animal like other reptiles.
 Its blood consists of plasma and
many types of cells floating in it,
as in frog.
 Its erythrocytes are
oval,nucleated, and biconvex.
NERVOUS SYSTEM
The nervous system of uromastix is more
advanced than amphibians.
 It lacks lateral line system.
 The nervous system consists of;
A. Central nervous system
B. Peripheral nervous system
C. Autonomic nervous system

BRAIN
OLFACTORY RECEPTORS
II. Jacobsons organs
Also called vomeronasal organs
Located in the roof of buccal cavity
Consist of a blind sac lined by olfactory
epithelium
Blind sac opens into buccal cabity by a
narrow duct
Innervation of ol. Epithelium
by
olfactory and trigeminal nerves
Smell food when food is hold in buccal
cavity
OLFACTORY ORGANS
Organs of smell
I. Olfactory sacs
II.Jacobsons organs
I. Olfactory sac ( Nasal chambers)
 Communicate with outside by external
nares
 External nares present just above tip of
snout
 Olfactory sac opens into buccal cavity by
internal nares
 Ol.sac lined by special olfactory cells
 Cells –sensitive to chemicals in rotation
form
EYE OF UROMASTIX
 The
eyes of uromastix shows
advancements as:
A. Both eyelids are movable.
B. Double layered conjuctiva protects
eyeball.
C. In retina no. of cone cells has
incresed.
D. A pad like conus papillaris projects
into the viterous humour.
PARTS OF EYE.
FIBROUS TUNIC
 Cornea
Sclerotic
 UVEA
•Choroid
•Iris
•Ciliary body
RETINA
FIBROUS TUNIC
•Thick and tough.
•Two distinct regions: anterior smaller,
transparent and exposed part called the
cornea
• posterior opaque part called the sclerotic.
•A small part of the sclerotic which is visible
on the sides of cornea is called the white of
the eye.
CHOROID OR UVEA
It is middle, vascular and pigmented
layer.
 It is differentiated into three regions.
The part lying on the inner side of the
sclerotic is called choroid.
It darkens the eye ball.
 The uvea forms a thick ring, the ciliary
body, at the junction of sclerotic and
cornea.
RETINA
Innermost layer.
Differentiated into three parts.
The part inner to choroid -optical part.
It is thick and sensitive.
 It contains more cones than rods so the wall lizard
has better day vision than night vision.
 The part of retina on the ciliary body - the ciliary
part and on the iris -the iridial part.
 Ora serrata, an irregular structure is present at the
junction of optical and ciliary part.
 An optic nerve originated from the retina from the
point called blind spot
From the blind spot a pigmented, blackish brown
,highly vascular ,corpus papillaris projects into the
vitreous humour.
Lens
A biconvex ,transparent crystaaline
lens is present behind the iris .
The lens is covered by a ring of soft
tissue called annular pad.
the lens is suspended from the ciliary
body by the suspensory ligament.
The cavity of eye ball is divided into two
unequal parts.
1) Anterior smaller part is called
aqueous humor.
2) Posteriro large part is called vitreous
humor
EAR OF UROMASTIX
External ear
Poorly developed.
It is in the form of a small, a
vertical pit behind the eye, the
external auditory meatus.
At the base of it, the tympanum
or tympanic membrane is present.
Middle ear
Present in the form of an air filled
cavity called the tympanic cavity.
Bonded externally by tympanum and
internally by the auditory capsules.
 It consist of one ear ossicle called
columella auris.
Which is divided into two parts .
1)inner bony stapes
2)outer cartilagenous extra columella
cartilage
Internal Ear
It is soft ,delicate structure enclosed
in the auditory capsule.
It is also called membranous
labyrinth.
It is filled with endolymph.
It consist of a bag like vestibule and
three semicircular duct.
Vestibule divided into 2 parts .
1)upper utriculus
2)lower sacculus
Three semicircular duct opens into
utriculus
REPRODUCTION
Uromastyx can lay anywhere from 5
to 40 eggs, depending on age and
species.
 Eggs are laid approximately 30 days
following copulation,incubation time
- 70–80 days.
 The neonates weigh 4–6 g, about 5 cm
(2 in) length.
 They rapidly gain weight during the
first few weeks following hatching.

REPRODUCTION