Transcript Class: Squamata

Infraclass: Teleostei
In this infraclass, all of the
fish are considered to be
the ray-finned fish. They
have a movable maxilla
and premaxilla and
modified muscles that allow
them to have a protrusable
mouth.
1
Infraclass: Teleostei
• Superorder: Osteoglossomorpha
– Bony Tongued fish
• Superorder: Elopomorpha
– Snake-like scale-less fish
• Superorder: Clupeomorpha
– Physostomes, which means that the gas bladder
has a pneumatic duct connecting it to the gut.
They typically lack a lateral line
• Superorder: Ostariphysi
– Their first few vertebrates are used to pass sound
from the swim bladder to the inner ear for acute
hearing
2
Infraclass: Teleostei
• Superorder: Protacanthopterygii
– These are fish that lack specialization
• Superorder: Stenopterygii
– Deep water fish. Bioluminescent
• Superorder: Scopelomorpha
– Deep water fish. Bioluminescent. They have
large eyes and adipose fins.
• Superorder: Acanthopterygii
– They usually have a Pelvic fin spine present.
3
Superorder:Osteroglossomorpha
Order: Osteoglossiformes
Arowana are freshwater
bony fish. They have a
unique structure called a
“bony tongue”. This is
actually derived from a
toothed bone on the floor of
the mouth and bite against
teeth on the roof of the
mouth. They can obtain
oxygen from the air by
sucking it into the swim
bladder which is lined with
capillaries.
4
Superorder: Elopomorpha
Order: Anguillidiformes
Morey Eel’s are found
in all tropical seas
usually in shallow
water with their body
wedged in a crevice.
Morey eels primarily
eat other fish and
mollusks. Their mouth
is often open (and
moving) to help water
circulate through the
gills
5
Superorder: Clupeomorpha
Order: Clupeiformes
The anchovy is a small green
fish with blue reflections due to a
silver longitudinal stripe that runs
from the base of the caudal fin.
They are found in the oceans
worldwide. Anchovies exhibit a
special way of feeding called
planktivory. These fish swim
through the water with their large
mouths open and strain out small
organisms (plankton) with fine,
sieve-like structures called gill
rakers.
6
Superorder: Clupeomorpha
Order: Clupeiformes
The sardines are a fish
found worldwide (but
named after an island in
the Mediterranean).
They are also called
pilchards. Sardines are
packed with nutrients
(omega-3 fatty acids,
Vitamin D, Calcium, B12, and protein).
7
Superorder:Ostariophysi
The superorder: Ostariophysi are fish that
have two main characteristics: they release
an alarm substance and their first few
vertebrates are used to pass sound from
the swim bladder to the inner ear for acute
hearing.
In this lab it includes the 1) Loachs, 2)
Characins, 3) Knifefish, and 4) Catfish
8
Superorder: Ostariphysi
Order: Cypriniformes
The Loaches are small
benthic freshwater fish.
Loaches are mostly
scavengers and are
omnivorous, usually not
very picky about their food.
Many live in waters of
generally poor quality and
some have adapted to
less-than-ideal water
conditions by being able to
gulp up atmospheric
oxygen from the air.
9
Superorder: Ostariphysi
Order: Characiformes
Piranha are carnivorous fresh
water fish living in South
American Rivers. They are
normally only 6-10 inches long.
They are known for their sharp
teeth and an aggressive appetite
for meat. They generally pose
no threat to humans. Humans
frequently swim in piranhainfested waters without attacks.
Their aggressiveness may
increase due to limited food but
rarely do they eat animals much
larger than themselves. They
have similar abilities to sharks to
detect blood in the water.
10
Superorder: Ostariphysi
Order: Characiformes
Hatchet Fish are a deep sea fish
that get their name from their
thin, hatchet-shaped body. Like
other deep sea fish, they have
the ability to create their own
lighting process known as
bioluminescence. Since the
photophores (organs producing
light) point downward, it is
believed they use them for
counter illumination to avoid
predators from below.
11
Superorder: Ostariphysi
Order: Cymnotiformes
The Knife fish are
primarily freshwater
inhabitants and have
organs derived from
muscle cells that are
adapted to the
generation of electric
fields.
12
Superorder: Ostariphysi
Order: Siluriformes
The Catfish are named for their
prominent barbels, which give
the image of cat-like whiskers.
Unlike other fish, There are
armour-plated types and also
naked types, neither having
scales. The glass catfish are
transparent because, like all
catfish they do not have scales
and they also don't have body
pigment. The glass catfish turns
milky white when dead,
suggesting it does something
during its life to keep it
transparent
13
Superorder: Protacanthopterygii
The Superorder: Protacanthopterygii are
fish that lack specialization. They are
important game fish
In this lab it includes 1) Salmon, 2) Pike and
3) Smelt
14
Superorder: Protacanthopterygii
Order: Salmoniformes
Salmon are typically
anadromous: they are born
in fresh water, migrate to
the ocean, then return to
fresh water to reproduce.
Both Atlantic and Pacific
Salmon are important to
recreational fishing around
the world. Currently in
California, Salmon fishing
has been suspended
because the numbers of
fish are dangerously low.
15
Superorder: Protacanthopterygii
Order: Salmoniformes
Trout are found in the
subfamily along with
salmon. Trout have fins
entirely without spines, and
all of them have a small
adipose (fatty) fin along the
back, near the tail. Trout
are found in clear streams
and lakes but are often
anadromous (like salmon).
16
Superorder: Protacanthopterygii
Order: Esociformes
Pike have the elongated,
torpedo-like form of
predatory fishes, with
sharply-pointed heads and
sharp teeth. They devour
fish up to one-third of their
own size. Pike are
cannibalistic; some 20% of
their diet consists of pikes
smaller than themselves.
Pike have little respect for
relative size and as a result
have been known to bite
swimmers and divers.
17
Superorder: Protacanthopterygii
Order: Osmeriformes
Smelt are small
anadromous fish. Smelt
has a character odor,
similar to the smell of
cucumbers. Smelt roe is
bright orange in color, and
is often used to garnish
sushi.
18
Superorder: Stenopterygii
Order: Stomilliformes
Dragonfish are among the
fish known as deep water
fish. Like other deep water
fish, they are capable of
bioluminescence. Unlike
other bioluminescent
creatures, they can glow
and perceive a red or bluegreen light (most species
only perceive blue light)
which allows it to see its
prey before they are seen.
19
Superorder: Scopelomorpha
Order: Myctophiformes
The lantern fish are found
in the deep sea. Like
other deep water fish,
they are bioluminescent.
They are a very common
deep water fish and they
make up about 65% of
the deep sea biomass.
20
Superorder: Scopelomorpha
Order: Myctophiformes
The Superorder: Acanthopterygii are
fish that have spiny fins.
In this lab it includes the rest of the fish in
lab.
21
Superorder: Acanthopterygii
Order: Mugiliformes
Mullet are ray-finned fish
found worldwide in coastal
temperate and tropical
waters, and in some
species in fresh water.
Mullets have served as an
important source of food.
Mullet does not keep well
after it is caught. If kept on
ice it may remain edible for
approximately 72 hours.
22
Superorder: Acanthopterygii
Order: Antheriniformes
Silversides are ray-finned
fish which usually have two
dorsal fins, the first with
flexible spines, and an anal
fin with one spine at the
front. The lateral line is
typically weak or absent.
Mosquito fish may now be
the most widespread
freshwater fish in the world,
having been introduced as
a biocontrol (to control
mosquitoes).
23
Superorder: Acanthopterygii
Order: Antheriniformes
Grunion are famous marine
bony fish found spawning on
the sandy beaches of
southern California. At night,
from March through
September, females burrow
backwards in the sand to lay
their eggs just after the
highest tides. They occur on
the second through fourth
nights after the full or new
moons. Each female is
accompanied by several
males which come to fertilize
the eggs.
24
Superorder: Acanthopterygii
Order: Beloniformes
Flying fish are a marine
fish. Their most striking
feature is their pectoral
fins, which are
unusually large, and
enable the fish to take
short gliding flights
through the air, above
the surface of the
water, in order to
escape from predators.
25
Superorder: Acanthopterygii
Order: Cyprinodontiformes
Desert Pupfish are an
endangered species
due to introduced
species and habitat
destruction/fragmentati
on. Desert pupfish are
well-adapted to the
rapid water temperature
changes (can tolerate
from 50-100 degrees F)
and high salinity they
experience in their
habitat.
26
Superorder: Acanthopterygii
Order: Stephanoberyciformes
Ridgeheads are also known as
bigscales, are a small, deepsea fish. These fish are named
for their large scales and
pronounced cranial ridges. The
family is sometimes termed
pseudoceanic because, rather
than having an even
distribution in open water,
ridgeheads occur in
significantly higher abundances
around structural oases,
notably seamounts and over
continental slopes.
27
Superorder: Acanthopterygii
Order: Gobiesociformes
Clingfishes are ray-finned
fish where in most species
the pelvic fins are modified
into a sucking disc. Most
species are marine, being
found in shallow waters of
the Atlantic, Pacific and
Indian Oceans.
28
Superorder: Acanthopterygii
Order: Gasterosteiformes
Sticklebacks are ray-finned
fish that have no scales,
although some species
have bony armour plates.
They are closely related to
pipefish and seahorses.
Niko Tinbergen's studies of
the behaviour of this fish
were important in the early
development of ethology as
an example of a fixed
action pattern.
29
Superorder: Acanthopterygii
Order: Synganthiformes
Sea Horses and Pipefish
are notable because they
are the only species in
which males become
“pregnant”. The males
have brood pouches which
the female uses an
ovipositor to deposit the
eggs. It is believed that the
pouch regulates salinity for
the eggs. These fish are
recognizable because of
their shape They have this
shape to help them hide in
the sea grass.
30
Superorder: Acanthopterygii
Order: Tetradontiformes
Porcupine fish are
recognizable for their
shape. They are often
confused with puffer fish
but porcupine fish have
spines. They blow up like
this to avoid predators.
They get this shape by
swallowing water (or air)
which limits what can eat
them.
31
Superorder: Acanthopterygii
Order: Tetradontiformes
Cowfish are recognizable for
their shape. They look this way
because The hexagonal platelike scales of these fish are
fused together into a solid,
triangular, box-like carapace,
from which the fins and tail
protrude. Because of these
heavy armoured scales, Cowfish
are limited to slow movements,
but few other fish are able to eat
the adults.
32
Superorder: Acanthopterygii
Order: Pleuronectiformes
Halibut are flatfish from
the family of the righteye flounders. When
the Halibut is born the
eyes are on both sides
of its head so it has to
swim like a salmon.
After about 6 months
one eye will migrate to
the other side of its
head so they lay on the
bottom for camouflage.
33
Superorder: Acanthopterygii
Order: Scorpaeniformes
Sculpin are bottom
feeders that are
generally not
considered good to eat,
and have sharp spines
rather than scales.
They use their large
pectoral fins to stabilize
themselves on the floor
of flowing creeks and
rivers.
34
Superorder: Acanthopterygii
Order: Perciformes
Girabaldi are California’s
State Marine Fish. They
are found in the Pacific
Ocean from Monterey Bay
to Baja California. They
are associated with reefs
and rocky sea-bottoms.
They eat mostly
invertebrates off the rocks.
They have the ability to
change their sex multiple
times during their life to
level out the ratio of males
to females.
35
Superorder: Acanthopterygii
Order: Perciformes
Striped Marlin are large
oceanic fish that can reach
nearly 12 feet and can
weigh up t0 450 lbs. They
are found in the tropical
and subtropical waters of
the Pacific and Indian
oceans. They are built for
speed in the open ocean
feeding on mackerel,
sardines, anchovy, squid
and crab near the surface.
36
Superorder: Acanthopterygii
Order: Perciformes
Wrasses are exclusively marine
in distribution usually in shallow
water habitats such as coral
reefs and rocky shores. The
Sheepheads are found in kelp
beds, on coral reefs and among
sea grasses. Its strong teeth
make this fish an opportunistic
predator. Sheephead wrasse
establish their own feeding patch
which is dominated by one male.
When he dies, one of the older
and larger females in the group
(around 30cm) changes colour
and turns into a male.
37
Superorder: Acanthopterygii
Order: Perciformes
Ocean Sunfish are the
heaviest known bony fish in
the world. It has an
average adult weight of 1
ton. Sunfish live on a diet
that consists mainly of Sea
jellies. As this diet is
nutritionally poor, they
consume large amounts in
order to develop and
maintain their great bulk
38
Superorder: Acanthopterygii
Order: Perciformes
Clownfish all form
symbiotic relationships with
sea anemones. The
clownfish feeds on
undigested matter which
otherwise potentially could
harm the sea anemone,
and the fecal matter from
the clownfish provides
nutrient to the sea
anemone.
39
Osteichthyes (External)
Fish have a torpedo shape which allows them to
reduce drag while swimming through the water.
They also have the following structures:
Ctenoid scales: embedded in the skin
Eyes: located on the sides with no eyelids and they do not have
binocular vision.
Lateral line: sensitive to pressure changes
Operculum: Hard covering over gills
Skeletal System: axial (skull and verebrae) and appendicular
(girdles and fins) which are very flexible for swimming
40
Osteichthyes (External)
Fish have many different fins:
Pectoral fins: Lift
Pelvic fins: Lift
Anal fins: Stability
Dorsal fins: Stability
Caudal fins: Propulsion
41
Osteichthyes (Internal)
System
Structure
Function
Muscular
Myomeres
Small contractions
Digestive
Stomach
Chemical Digestion
Pyloric Ceca
Increases SA
Intestine
Absorption of nutrients
Liver
Storage, conversion, removes toxins
Pancreas
Secretes enzymes
Spleen
Immune response
Kidneys
Filtration
Urinary Bladder
Holds Urine
Sinus venosus
Receives venus blood
Atrium
Pumps blood into ventricle
Ventricle
Pumps blood into body
Bulbus arteriosus
Maintains even blood flow
Excretory
Circulatory
42
Osteichthyes (Internal)
System
Structure
Function
Respiratory
Gills
Gas Exchange
Nervous
Brain
Nervous system control
Spinal Cord
Nervous signals
Ovaries
Produce Eggs
Testis
Produce Sperm
Swim Bladder
Buoyancy
Reproductive
Swim Bladder
43
Class: Amphibia
The word amphibian means: two lives which
refers to the metamorphosis seen in many
frogs. The skin is smooth and moist. They
have a three chambered heart with a double
circulation system. This class includes three
orders: Urodela (salamanders), Anurans (frogs
and toads), and apodians (caecilians).
44
Order:
Urodela
The order Urodela includes the
salamanders which retain their tail as an
adult. Their limbs are at right angles to
their bodies. They are carnivores.
45
Venomous vs. Poisonous
In general, venomous
animals must inject
their toxin via a bite or
sting whereas the
toxin from a
poisonous animal
must be ingested.
• Southern
Pacific
Rattlesnake
(Venomous)
• California
Newt
(Poisonous)
46
Order:
Urodela
California Newts are poisonous animals because
they secrete toxins thorough their moist skin and
usually cause harm when they are ingested. The
toxins are called tarichatoxin and they are very
strong neurotoxins. The toxins have been known
to kill humans and other animals that have
attempted to eat California Newts.
47
Order: Urodela
Another species of
Salamander in the
area is the
Ensantina. It is
considered a ring
species in
California’ central
valley. The
ensatina can
usually be found
under logs, brush,
by or in streams
and lakes, and in
other moist places.
48
Order: Urodela
Another species of salamander in the area is the
Slender California Salamander. It is found in oak
woodlands, grasslands and riparian zones. They
may be found resting beneath leaf litter or other
rotting logs or rocks providing a wet environment.
The slender shape of the California slender
salamander is well adapted for penetration of
earthworm or termite burrows to forage for prey. 49
Order: Urodela
Another species of salamander in the area is the
Lungless Salamander. They lack lungs, conducting
respiration through their skin, and the tissues lining
their mouths. They must keep these surfaces moist
and so have to live in damp environments, such as
beneath logs, in caves or in wet rock crevices, and
only venture out in humid weather.
50
Order:
Anurans
The order Anurans includes frogs and
toads. They lose their tail as adults. Their
hind limbs are adapted for jumping. Their
tongue is connected to the front of their
mouth. They secrete a mucus for
protection.
51
Class: Amphibia
Order: Anurans
Some toads and frogs are
poisonous because they
secrete toxins through their
skin. Toads tend to have
bumpier skin and large
parotid glands which may
secrete toxins. Frogs tend to
have smoother skin and no
parotid glands. Poison
Arrow Frogs obtain their
poison from eating other
toxic animals such as
centipedes
52
Class: Amphibia
Order: Anurans
The spadefoot toads are burrowing frogs. They are
round, with short legs and protruding eyes. As
suggested by their name, this frog has hard,
keratinous protrusion present on their feet, which
helps them to dig. Like most burrowing frogs, they
will dig backwards into the ground.
53
Class: Amphibia
Order: Anurans
The Red Spotted toads are native to the
southwestern United States and northwestern
Mexico, especially Baja California. It occurs primarily
along rocky streams and riverbeds, often in arid or
semi-arid regions. It is very localized on the coastal
slope, but widespread in the deserts. In dry areas it
needs seasonal pools or even temporary rain
54
puddles to use for breeding.
Class: Amphibia
Order: Anurans
The California Tree Frog is a cryptically colored
species, often resembling granitic stones. The
California tree frog has conspicuous toe webbing
and pads, and its dorsal skin is roughened and
warty. This is a species most likely to occur along
streams with abundant boulders.
55
Class: Amphibia
Order: Anurans
The Pacific Tree Frogs are the most common frogs on the
west coast of North America. They can be identified by the
black or dark brown eye stripe that goes over the eye from the
nose to the shoulder. Their toes are long and only very
slightly webbed. On the end of each toe, there is a round
sticky toe pad or disks used for climbing and sticking to
surfaces. This tree frog makes its home in riparian habitats as
well as woodlands, grassland, chaparral, pasture land, and
56
even urban areas including back yard ponds.
Class: Amphibia
Order: Anurans
Bullfrogs are the largest frog in the United States. They are
an introduced species here in the west. They have become a
problem here because they eat basically anything they can
get into their mouth and have had an impact on the local
fauna. They can be easily recognized by their size and the
large tympanic membrane behind their eyes.
57
Class: Amphibia (External)
The three functions of the skull of an amphibian are 1)
protection of the nervous system, 2) feeding apparatus, and
3) a means for respiration. The skeletal system is not as
flexible as the fish because it has become a rigid frame of
transmitting force from the hind limbs to the body. The
appendicular skeleton is now more modified. The pectoral
girdle absorbs shock during landings. The pelvic girdle is
modified for jumping. The sacral hump is made from the
protusion of the pelvic girdle. Frogs lack ribs (except a few
primitive ones). The tongue is attached to the front of the
mouth. The tympanic membrane is an area of tight skin that
acts like an eardrum. The eyes have eyelids and a nicitating
membrane (a transparent membrane).
58
Class: Amphibia (Internal)
System
Structure
Function
Muscular
Muscles
Contractions
Digestive
Stomach
Chemical Digestion
Intestine
Absorption of nutrients
Liver
Storage, conversion, removes toxins
Gall Bladder
Store Bile
Pancreas
Secretes enzymes
Spleen
Immune response
Kidneys
Filtration
Urinary Bladder
Holds Urine
Atrium
Pumps blood into ventricle
Ventricle
Pumps blood into body
Excretory
Circulatory
59
Class: Amphibia (Internal)
System
Structure
Function
Respiratory
Lungs
Gas Exchange
Nervous
Cerebrum
Higher Thought
Olfactory Lobe
For smell
Optic Lobe
For sight
Medulla
Oblongata
Sends messages between brain and SC
Spinal Cord
Transports signals
Ovaries
Produce Eggs
Testis
Produce Sperm
Reproductive
60
“Reptilia”
Unlike amphibians, reptiles have a tough, dry skin.
They must obtain almost all their oxygen skeletal
system is through their lungs. Most reptiles lay
amniotic eggs that allow them to complete their life
cycles on land. The old class “Reptilia” has been
divided into four new classes:
- Class: Testudines (Turtles and Tortoises)
- Class: Sphenodontia (Tuataras)
- Class: Squamata (Lizards and Snakes)
- Class: Crocodilia (Crocodiles and Alligators)
61
Class: Testidunes
Turtles evolved on land then returned to the
water. Evidence that supports this is they lay
their eggs on land. The shell contains two
pieces: the lower part is called the plastron
and the upper part is called the carapace.
62
Class: Testidunes
There are six species of sea turtles. All sea
turtles have low, streamlined shells and
forelimbs that have been modified into
flippers. Sea turtles spend most of their life at
sea but must return to land to lay their eggs.
63
Class: Testidunes
Tortoises differ from other turtles in that they
usually have domed shells and elephant-like
limbs. Desert Tortoises have well developed
claws and are able to dig deep burrows to
escape the desert heat.
64
Class: Testidunes
Mata matas are a freshwater turtle
found in South America, primarily
in the Amazon. The mata mata's
shell appearance resembles a
piece of bark and its head
resembles fallen leaves. As it
remains motionless in the water, its
skin flaps enable it to blend into the
surrounding vegetation, until a fish
comes close The mata mata
thrusts out its head and opens its
large mouth as wide as possible,
creating a low-pressure volume
that sucks the prey into the turtle's
mouth. The Matamata snaps its
mouth shut, the water is slowly
expelled, and the fish is swallowed
whole as the mata mata cannot
chew due to the way its mouth is
constructed.
65
Class: Testidunes
The Red-eared Slider
is a semi-aquatic turtle.
It is a native of the
southern United States,
but has become
common in various
areas of the world due
to the pet trade. The
native turtle to this area
is the Western Pond
Turtle. They are being
threatened by bullfrogs
and habitat destruction.
66
Class: Testidunes
The soft-shelled
turtles are fresh
water turtles and are
called “soft-shelled”
because their
carapace lacks
scutes (scales).
They are carnivores
that need to be
submerged to be
able to swallow food.
67
Class: Sphenodontia
The tuataras are
lizard-like animals
but they lack
external ears. They
are very primitive
(similar to mesozoic
reptiles) They have a
well developed third
eye just below the
skin.
68
Class: Squamata
The class Squamata
includes lizards,
geckos, iguanas,
skinks, and
chameleons. They
are terrestrial,
burrowing, aquatic,
and arboreal. They
have moveable
eyelids which
separate them from
snakes.
69
Class:
Squamata
Many species of lizards are capable of tail autotomy.
This occurs when the tail breaks off and continues to
move which allows the lizard to escape from
predators. Zebra-tailed lizards have a black and
white striped tail which they flash up and down to
divert predators towards the tail. Juvenile Western
Skinks have a bright blue tail which tends to attract
predators to the tail so that the lizard can escape.
70
Class:
Squamata
Chuckwallas are large herbivorous lizards that
live in rocky, desert areas in the Southwestern
U.S. When predators approach, they wedge
themselves between two large rocks, gulp air,
and distend their bodies making them difficult to
remove.
71
Class:
Squamata
There are 15 species of horned lizards.
Horned lizards have scales that match
the color of the local substrate and they
have dorsoventally flattened bodies.
This allows enables them to blend into
the environment. When threatened by
predators, many species of horned
lizards will squirt blood from their eyes
to deter predators. Horned lizards are
myrmecophagous (ant eaters). They
have specialized teeth for eating ants
and an enlarged stomach that allows to
better digest ant meals. Horned lizards
also do a behavior called “rain
harvesting” in which they arch there
body during and use scales to channel
raindrops from their body towards there
mouth.
72
Class:
Squamata
Gila monsters and Mexican
Beaded lizards are both types
of Heloderms. They are the
only two venomous lizards in
the world. The venom is
produced by glands on the
outside of the lower jaw and
is expelled into the mouth
along grooves in the teeth
and injected by chewing. The
tail of Heloderms is a fat
storage organ.
73
Whiptail lizards are slim
bodied, long-tailed, active
lizards. Many species
consist only of females and
reproduce via
parthenogenesis in which
an unfertilized egg
develops into a new female
individual. Our local
species, however, are not
parthenogenic.
Class:
Squamata
74
Desert Iguanas are large
bodied lizards with small,
rounded heads. They are
capable of tolerating body
temperatures of 42 °C (108
°F) which is higher than
any known vertebrate.
Desert Iguanas can avoid
predators because they are
active during the hottest
periods of the day when
most species are unable to
cope with the heat.
Class:
Squamata
75
Basilisk Lizards are lizards found
in Central and South America
rainforests near rivers and
streams. The basilisk is part of
the Corytophanidae family. It
has the nickname the "Jesus
Lizard" because when fleeing
from a predator, it runs on top of
water for a brief distance.
Basilisks have large hind feet with
flaps of skin between each toe, it
can open up this webbing to
increase the surface area on the
water relative to its weight, thus
allowing it to run on water for
short distances.
Class:
Squamata
76
Chameleons are zygodactylic: on each
foot the five toes are fused into a group
of two and a group of three, giving the
foot a tongs-like appearance. These
specialized feet allow chameleons to
grip tightly to narrow branches.
Chameleons have a long tail that is able
to curl up. It is used to balance on tree
limbs. Sometimes it is used as a
weapon. A chameleon uses its tail
almost like a fifth leg. Their eyes are the
most distinctive among the reptiles.
Their eyelids are fused. They can rotate
and focus separately to observe two
different objects simultaneously.
Chameleons have very long tongues
(sometimes longer than their own body
length) which they are capable of rapidly
extending out of the mouth.
Class:
Squamata
77
This Old World Lizard family can
be described as lizards that usually
have well-developed, strong legs..
One of the key distinguishing
features of the agamids is their
teeth, which are borne on the outer
rim of the mouth (acrodont), rather
than on the inner side of the jaws.
(shared with chameleons).
Bearded dragons include spiny
scales arranged in rows and
clusters. These are found on the
throat and back of head. These
lizards are often called dragons or
dragon lizards. Bearded dragons
will expand their scales around
their neck when threatened. The
species also displays a handwaving gesture, thought to draw an
attack from any predator that may
be in the area, however this can
also be used as a form of
communication between the
species.
Class:
Squamata
Family:
Agamidae
78
Many Chameleons have head
or facial ornamentation. They
have long tongues and lack
ears. Chameleons are didactyl:
(on each foot the five toes are
fused into a group of two and a
group of three, giving the foot a
tongs-like appearance). Their
eyes are the most distinctive
among the reptiles. The upper
and lower eyelids are joined,
with only a pinhole large
enough for the pupil to see
through. They can rotate and
focus separately to observe two
different objects
simultaneously.
Class: Squamata
Family:
Chameleonidae
79
The baskalisk lizards typically
have well-developed head
crests in the shape of a casque
(a French word for helmet).
These lizards are often called
“Jesus Christ” lizards because
they may run on water when
threatened.
Class: Squamata
Family:
Corytophanidae
80
The family characters of
the iguanids are: a body
covered with horny
scales, without bony
plates or without large
square plates on the
abdomen; there is
generally a crest along
the back or the tail. This
family includes
Chuckwallas, Desert
Iguanas, Marine Iguanas
and Green Iguanas.
Class: Squamata
Family: Iguanidae
81
Marine Iguanas is an iguana
found only on the Galápagos
Islands that has the ability,
unique among modern lizards,
to live and forage in the sea,
making it a marine reptile. The
Iguana can dive over 30 ft (10
m) into the water. The Green
Iguanas are found in the United
States as feral populations in
South Florida (including the
Florida Keys), Hawaii, and the
Rio Grande Valley of Texas.
Class: Squamata
Family: Iguanidae
82
The North American
Spiny lizards are
relatively small (most <
10 cm snout-vent length)
lizards, and represent a
diversity of forms. They
range in the number and
size of the spines. This
family includes: Zebratailed Lizards (open
deserts with spotty
vegetation), Western
Fence Lizards (a variety
of habitats – most
common local lizard),
Side-blotched Lizards
(most common desert
species) and Horned
Lizards.
Class: Squamata
Family:
Phrynosomatidae
83
Anole lizards are frequently and
incorrectly called American
chameleons or geckos, although
they are not closely related to
either of those groups. In fact,
they are more closely related to
iguanas. These misconceptions
are likely due to their ability to
alter their skin color and run up
walls. Anoles are small and
common lizards that can be found
throughout the southeastern
United States, the Caribbean, and
various other regions of the
Western world. A large majority of
them sport a green coloration.
They are widespread due to the
pet trade and eggs in imported
plants.
Class: Squamata
Family:
Polychrotidae
84
Geckos are small to
average sized lizards
belonging to the family
Gekkonidae, found in warm
climates throughout the
world. All geckos, have no
eyelids and instead have a
transparent membrane
which they lick to clean
Class: Squamata
Family:
Geckonidae
85
The Southern alligator
lizard is a lizard common
throughout Southern
California and can be found
in grasslands, chaparral,
and forests as well as urban
areas. The lizards can
frequently be found near
human habitation and are
notable for their fearless
self-defense; they will often
bite and defecate if handled.
Class: Squamata
Southern Alligator
Lizard
86
The California Legless
Lizard is a limbless,
burrowing lizard often
mistaken for a snake. (They
have moveable eyelids).
They live in loose, sandy
soils or leaf litter, typically in
sand dunes along the coast.
Class: Squamata
California Legless
Lizard
87
This lizard is a
relatively large lizard.
It has a large head,
long nose, and a long
round tail that can be
longer than its body.
They prefer to inhabit
arid and semiarid
plains growth, like
bunch grass, alkali
bush, sagebrush,
creosote bush and
other scattered low
plants.
Class:
Squamata
Long-nosed
Leopard
Lizard
88
Class: Squamata
The class Squamata
includes snakes.
They lack moveable
eyelids. They
contain a structure
called a Jacobson’s
organ which are
olfactory organs
used to “taste” their
environment.
89
Venomous animals usually
inject there toxin via a bite or
sting. The toxin from a
poisonous animal must
generally be ingested.
Class:
Squamata
Snake venom contains a
variety of molecules that often
fall into two categories: those
that are hemotoxic (dissolve
tissue) and those that are
neurotoxins (block nervous
functions).
Southern Pacific rattlesnakes
(like most of the rattlesnakes
found in the U.S.) have venom
that is primarily hemotoxic.
Mojave Rattlesnakes, however,
often have large amounts of
neurotoxins in their venom.
90
Rattlesnakes (including the
Southern Pacific, Mojave, and
Sidewinder) have large, hollow,
moveable fangs that are located
at the front of the upper jaw. In
biting, the fangs are swung
forward from their folded position
of rest and the victim is stabbed
and envenomated in a rapid
thrust.
Rattlesnakes are capable of
controlling their venom
expenditure depending on the
prey and will inject larger
amounts of venom in larger prey.
Despite popular belief, large
rattlesnake are more dangerous
and inject more venom that an
small rattlesnake.
Class:
Squamata
91
Rattlesnakes (including the
Southern Pacific, Mojave,
and Sidewinder) are all
pitvipers. Pit vipers have a
distinct loreal pit – a
temperature-sensitive
structure on each side of the
face between the eyes and
nostrils, which helps them
locate prey. To the left is an
picture generated by a
computer to demonstrate
how a snake might
thermally visualize a rat.
Class:
Squamata
92
Cobras and Sea Snakes have
short, fixed fangs (unlike the
long, folding fangs of pit vipers).
Cobras, sea snakes and their
relatives are collectively called
Elapids. The Venom of elapids
tends to be the most toxic of all
snakes because it often has
large amounts of neurotoxins.
The largest of these, the King
Cobra, is the largest venomous
snake in the world. Although its
venom is not extremely toxic, it
injects a large amount of venom
with every bite. A typical bite
contains enough venom to kill
20 people. King Cobras tend to
eat other snakes.
Class:
Squamata
93
Class: Squamata
Related to Cobras, the Inland
Taipan Snake is the most
venomous of all snakes.
Found in Australia, one bite
contains enough venom to
kill 100 people. Sea snakes
are related to some of the
most potent venomous
snakes but some have gentle
dispositions and bite only
when provoked, while others
are much more aggressive.
They have paddle-like tail
that has increased their
swimming ability and to a
varying degree, the bodies of
many species are laterally
compressed.
94
The Boidae are a family of
non-venomous snakes found in
America, Africa, Europe, Asia
and some Pacific Islands.
Nearly all have a relatively rigid
lower jaw with a coronoid
element, as well as a vestigial
pelvic girdle with hind limbs
that are partially visible as a
pair of spurs. This family
includes the Anaconda, African
Rock Python, and the rosy boa.
Class:
Squamata
Family:
Boidae
95
The Colubridae is a broad
classification of snakes that
includes about two thirds of all
snake species on earth.
Colubrid species are found on
every continent, except
Antarctica. They are
characterized by highly flexible
jaws, a body almost completely
covered in scales, generally
relatively wide ventral scales
and a standard complement of
enlarged scales on the head,
the lack of any vestiges of the
hind limbs, the absence of the
coronoid bones of the lower
jaws, and commonly the
presence of Duvernoy's glands
on either side of the head
behind the eye.
Class:
Squamata
Family:
Colubridae
96
Ring-necked snakes are found in
open woodlands near rocky hillsides,
or in wetter environments with
abundant cover or woody debris.
They are are best known for their
unique defense posture of curling up
their tails exposing their bright redorange posterior, ventral surface
when threatened. Common Garter
snakes are found from forests, fields,
and prairies to streams, wetlands,
meadows, marshes, and ponds, and
it is often found near water. It is a
semi-aquatic animal like most
snakes.
Class:
Squamata
Family:
Colubridae
97
Coachwhips are thin-bodied snakes
with small heads and large eyes with
round pupils. They tend to be highstrung, and often bolt at the first sign
of a potential threat. They are
extremely fast moving snakes. The
Western Shovel-nosed snake is
found in loose sandy areas such as
washes, dunes, sandy flats and rocky
hillsides with sparse vegetation is
usually sparse. The underset lower
jaw, muscular body, smooth scales,
and shovel-shaped nose make this
snake very good at “swimming” in the
sand.
Class:
Squamata
Family:
Colubridae
98
King snakes are also
common snakes in our
area. King snakes are
non-venomous and
primarily eat other snakes
including rattlesnakes.
Class:
Squamata
Family:
Colubridae
99
Gopher snakes are
one of the most
common snakes in
our area. When
threatened, it often
will hiss loudly and
flatten and broaden
its head and
vibrates its tail. In
dry leaves, the
vibrating tail tail
may sound like a
rattlesnake and
deter predators.
Gopher snakes,
however, are not
venomous.
Class:
Squamata
Family:
Colubridae
100
The Elapidae family of
snakes (known as
elapids) includes
cobras, Taipans and
Sea Snakes. All
elapids are venomous,
and some of the most
venomous snakes in
the world are found
within this family.
Class:
Squamata
Family:
Elapsidae
101
All viperids have a pair of
relatively long hollow fangs
that are used to inject
venom from glands located
towards the rear of the
upper jaws. This family
includes the rattlesnakes.
(Red Diamond Rattlesnake,
Western Diamondback
Rattlesnake, Speckled
Rattlesnake and the
Western Rattlesnake.
Class:
Squamata
Family:
Viparidae
102
Other Snakes
Red Diamond
Rattlesnake
Western Rattlesnake
103
Other Snakes
Speckled
Rattlesnake
Western
Rattlesnake
104
Class:
Squamata
Sidewinders have a unique
sidewise locomotion in which
their body moves in an Sshaped curve. This form of
movement is rapid and
minimizes slippage on loose
soil and it also reduce heat
uptake from hot surfaces
because of the greatly
reduced contact. Sidewinders
also have “horned” scales
over their eyes which can be
folded down when entering a
burrow to protect the eye.
105
Other Snakes
Southern Pacific
Rattlesnake
Mojave
Rattlesnake
106
The crocodilia are the
largest living reptiles.
Among the living
reptiles, they are most
closely related to
dinosaurs. They have
a four chambered
heart like mammals
and birds. Alligators,
Crocodiles, Caimans
and Gavials are all in
the class Crocodilia.
Class:
Crocodilia
107
Class:
Crocodilia
Alligators tend to have wider, rounded, Ushaped snouts whereas Crocodiles tend to
have more a longer, more pointed, V-shaped
snout. Also, the fourth tooth on the lower jaw
of crocodiles sticks up and over the upper lip
so that it can be seen when the crocodiles
mouth is closed. In Alligators, this tooth can
not be seen when the mouth is closed.
Caimen all have wide, flat heads with
rounded noses. Eyeline ridge is slightly more
pronounced than in the closely related
American alligator, Alligator mississippiensis.
When mouth is closed, only teeth from upper
jaw are visible. Gavials have very narrow,
long pointed snouts. The largest of the
crocodiles is the Saltwater Crocodile found in
and around northern Australia. Saltwater
Crocodiles can be as large as 18 feet and
weigh 3000 pounds.
108
From Top Left
Gavial
Alligator
Crocodile
Caiman
109