Chapter 17 and 18 Notes, Reptiles and Amphibians - PowerPoint Presentation

Slide1

Chapter 17 and 18 Notes, Reptiles and Amphibians

Slide2

Characteristics of Class Amphibia

Most amphibians

are

tetrapods

, meaning they have

four limbs

, but

some are limbless

.

Amphibians have

smooth, moist skin

.

Amphibians

respire by lungs, skin, and gills;

either

separately or in combinations

.

Amphibians have a

3-chambered heart

, with

two atria and one ventricle

.

Amphibians are

ectotherms

, meaning they

require an external source of heat

.

Slide3

Caecilians: Order

Gymnophiona

(

Apoda)

Caecilians have a

long slender body

that is

limbless

and they

live in burrows

.

Caecilians

live in tropical regions

.

Caecilian's

eyes are small

and they are

almost completely blind

.

Caecilians are

carnivores

that

eat mostly worms

and

other invertebrates

.

Fertilization is internal

, but

eggs are usually deposited

in

moist ground near the water

.

Slide4

Caecilians

Slide5

Salamanders: Order

Urodela

(

Caudata)

Salamanders are

tetrapod

amphibians

with tails

.

Most

of the

salamanders

in

North America

are

less than 6 inches (15 cm) long

.

Some

are

much larger

, like the

giant Japanese salamander

that

can exceed 4-5 feet (1.5 meters)

.

Most salamanders have

four equal-sized limbs

set at

right angles to their body

.

Salamanders are typically

carnivores

that

prey on worms, arthropods

, and

mollusks

.

Slide6

Salamander

Slide7

Giant Japanese Salamander

Slide8

Frogs and Toads: Order

Anura

(

Salientia)

Frogs and Toads

lack tails as adults

.

All frogs and toads

bear a tail in the larva stage

.

Frogs and Toads are

adapted for jumping

.

The name Anura means “without a tail” and Salientia means “jumping or leaping”.

Eggs

of frogs and toads

hatch into a tadpole

, having a

finned tail

,

internal and external gills

,

no legs

, and tadpoles are

herbivores

.

Slide9

Metamorphosis in Frogs

Slide10

Frogs and Toads: Order

Anura

(

Salientia)

Adults

are much

different

than the

larval form

.

After

tadpoles

go through

metamorphosis,

frogs and toads

lose their tail and gills,

develop legs

, and

become carnivores

.

Frogs and Toads

vary in size

from the

West African Goliath frog (30 cm long or 1 ft.)

, to some that are

less than 1 cm in length

.

The

Goliath frog

can

consume rats

and

ducks

.

Slide11

Goliath Frog

Slide12

Frogs and Toads: Order Anura (Salientia)

Frogs are

found all over the world

, but the

majority

of them are

found in tropical regions

.

Those that live in

colder climates

,

hibernate in the winter

.

Some

frogs

hibernate

in the

soft mud

of

ponds

and

streams

.

Terrestrial frogs

, such as

tree frogs

,

hibernate

in the

humus (leaf litter)

of the

forest floor

.

Some

can even

withstand freezing temperatures

by

converting glycogen from their liver into glucose,

which

prevents ice-crystal formation

.

Slide13

Frogs and Toads

Slide14

Frozen Alaskan Wood Frog

Slide15

Class Reptilia

Body is covered in

scales

made of

keratin

.

Most are

tetrapods

, some are

limbless

.

Respiration

is by

lungs

, not by skin or gills.

3-chambered heart

in

most

, with the

exception

of the

crocodilians

which have a

4-chambered heart

.

Ectothermic

; body temperature is

modified by

behavioral thermoregulation

.

Fertilization

is

internal

Amniotic

eggs

covered with

leathery shells

with

internal embryonic membranes

.

Slide16

Characteristics of Reptiles

Reptile

scales are different than fish scales

.

The scales on a reptile are

made of

keratin

and are

similar

in material

to mammal skin

.

Reptile

eggs are amniotic

, meaning they have

internal membranes

, (like the

chorion

and

allantois)

which help

exchange gas and remove metabolic waste

.

The

tough leathery shell

also

allows the eggs

to be

laid in dry terrestrial environments

.

Slide17

Reptile Scales

Slide18

Amniotic Egg of a Reptile

Slide19

Characteristics of Reptiles

Reptiles have

a double pump circulation

with a

systemic

(body) and

pulmonary

(lungs) circulation.

Reptiles

do not have completely separated ventricles

, which causes

partial mixing of deoxygenated and oxygenated blood

.

Reptilian lungs

are

more efficient than amphibian lungs.

Their

rib cage can expand and contract

, but, they

lack a muscular diaphragm

like mammals.

Slide20

Circulatory System of Amphibians

Slide21

Circulatory System of Reptiles

Slide22

Circulatory System in other Vertebrates as a Comparison

Slide23

Turtles: Order Testudinata

The body of a turtle is enclosed in

two shells;

the

dorsal shell

called the

carapace

and the

ventral shell

called the

plastron

. The

carapace is fused with the ribs and the vertebrae

.

Shell

provides protection for the head, arms, and legs

, which

can be retracted into the shell

.

The turtle

cannot expand the chest to breath

so they use

abdominal and pectoral muscles

to

draw air into the lungs

.

Slide24

Turtle Skeleton

Slide25

Turtles: Order Testudinata

Turtles

lack teeth

, but they have

beak-like jaws

lined with tough plates

made of keratin.

Turtles are

almost completely deaf,

but they have a

good sense

of

smell

and

vision.

Turtles are

oviparous

, with

internal fertilization

.

All turtles

, including marine forms

bury their amniotic eggs in the ground

.

Nest

temperatures determine the sex

of the turtles;

low temperatures males, high temperatures females

.

Slide26

Turtles: Order Testudinata

Leatherback marine turtles can reach 2 meters in length

and weigh up to

725 kg

(about as heavy as a large moose at

1500

lbs

)

Some land tortoises

like the Galapagos Island tortoises

can weigh several hundred kilograms

.

Most tortoises

are

slow moving

, moving only a

few hundred meters per hour

.

Their

low metabolism

may explain their

longevity.

Some living

over 150 years

.

Slide27

Leatherback Sea Turtle

Slide28

Galapagos Island Tortoise

Slide29

Order Squamata: Lizards and Snakes

Approximately 95%

of

all known living reptiles

belong in this order.

One feature of the

order

squamata

that has made them some of

the most successful and diverse

of all the

reptiles

is the

kinetic skull

.

The kinetic skull is an adaptation that

allows the snout to be tilted upward, in order to capture and manipulate their prey

and

increase the force of the jaws

.

Slide30

The Kinetic Skull

Slide31

Lizards: Suborder

Sauria

Suborder

Sauria

(a suborder of the order

Squamata

)

i

ncludes

geckos, iguanas, skinks, and chameleons

.

Most

lizards are

tetrapods

, except for the

glass lizards

which

are limbless

.

Lizards

have

movable eyelids, snakes do not

.

Lizards

have

rods and cones

in their eyes which give them

excellent daytime vision

, except some nocturnal geckos that have only rods.

Most lizards

have

external ears

,

snakes do not

.

Slide32

Gecko Feet, The Wall Climbers

Slide33

Iguanas

Slide34

Skinks

Slide35

Chameleons

Slide36

Glass Lizards

Slide37

Lizards: Suborder Sauria

Lizards are also

well adapted

to living in

hot, arid climates

like the

desert.

Lipids (fats) in their skin minimize water loss

.

Concentrated urine conserves water

.

Some lizards

, like the

Gila monster

of the southwestern U.S.,

store fat in their tails

, which they use for an

energy and water reservoir

.

Ectotherms do not require as much energy

to live as do endotherms.

Slide38

Gila Monster

Slide39

Snakes: Suborder Serpentes

Snakes are

limbless

reptiles and they

usually

they

lack pelvic and pectoral girdles

.

Numerous vertebrae and ribs

provide

support, protection

, and

more leverage

for the muscles to

increase efficiency

in

locomotion

.

The

kinetic skull

enables snakes to

swallow prey several times their size

.

Snakes

do not

have

movable eyelids

, but they do have

permanently covered transparent eyelids

.

Slide40

Snake Skeleton

Slide41

Snakes: Suborder Serpentes

Snakes

do not have

any

external ears

.

Snakes

do have internal ears

that can detect

limited low frequency sounds.

Snakes are

sensitive to ground vibrations

.

Most snakes

have relatively

poor vision

.

Some arboreal

(tree-dwelling)

snakes

have

excellent binocular

(stereoscopic)

vision

, that is useful for tracking prey through branches

.

Slide42

Snakes: Suborder Serpentes

Probably the

most advanced sensory organs used by snakes

is called the

Jacobson's

organ,

which is an organ that can

detect chemicals in the air

from a

pair of pits

that are found on the

roof of their mouth

.

The Jacobson's organs are

lined with olfactory sensory neurons

.

Their

forked tongue, flicks the air to pick up scent molecules

, which are

carried to the Jacobson's organ.

Slide43

Jacobson's Organ

Slide44

Snakes: Suborder Serpentes

Most snakes kill their prey by grabbing it and swallowing it whole

, but this can be dangerous.

Constrictor

snakes,

kill their prey first by constriction

, then swallow the prey whole.

Some constrictors

can swallow prey as large

as

deer, leopards, and even crocodiles

.

The

muscles of constrictors are very large,

but, the

large muscles slow them down

.

So

most constrictors wait and ambush their prey

rather than seek out their prey.

Slide45

Constrictors

Slide46

Snakes: Suborder Serpentes

Other snakes

kill their prey with venom

before swallowing it whole.

Vipers

(members of the

Viperidae

family

) have

large, movable fangs

at the front of their mouths.

Elapids

; Cobras, mambas, and coral snakes

(members of the

Elapidae

family

) have

permanently erect fangs

.

Some vipers

are called

pit vipers

because they possess special

heat-sensitive pit organs

on their heads that

detect infrared heat

produced by

endotherms

(warm-blooded animals).

Slide47

Vipers (

Viperidae

)

Slide48

Cobra and Coral Snake (

Elapidae

)

Slide49

Viperidae

(Rattlesnake Skull)

Slide50

Elapidae

(Cobra Skull)

Slide51

Pit Vipers

Slide52

Snakes: Suborder Serpentes

Many of the

North American venomous snakes

are

pit vipers

, like the

rattlesnakes, water moccasins

, and the

copperheads

.

Approximately

8,000 bites

are reported

in the US each year

, but usually, only

5-10

of those reported bites

result in death

.

There are

two types of snake venom

; the

neurotoxic

kind that attacks the

optic nerves

causing blindness

, and the

phrenic nerve

of the

diaphragm

causing

suffocation

.

Slide53

Snakes: Suborder Serpentes

The other type of snake venom is a

hemorrhagin

type, that

destroys red blood cells, blood vessels

, and causes

internal hemorrhaging

of

internal tissues

.

It is estimated that

worldwide

,

50,000-60,000 people die each year from snakebites

.

Most

are in

third world tropical countries

where people are

not properly fit with good shoes,

and

medical facilities are lacking

.

Slide54

Order

Sphenodonta

: Tuataras

Only

two living species

in

New Zealand

.

Strange

lizard-like reptiles

, although the

skull is different

than that of

snakes and lizards

.

Skull is not movable

like the kinetic skull of the order

Squamata

(snakes and lizards).

They also have

a median “third eye” with a

retina and lens

and is

sensitive to light

, but it is unusual because it is

covered with scales

.

Slide55

Tuatara

Slide56

Order Crocodilia: Crocodiles and Alligators

Long

,

massive skull

and

jaw

that provides a

wide gape

and a

rapid, powerful bite

.

Teeth are set in sockets

, which is

a trait

that they

share in common

with

some of the dinosaurs

.

Crocodilians have a

secondary palate

that

allows them to breath

when the

mouth is full of water and/or food

.

In

crocodiles

, some of the

lower jaw teeth overlap with the narrow upper jaw

.

A

lligators lack this feature

.

Slide57

Crocodilian Secondary Palate Covering the Back of the Throat

Slide58

Crocodiles and Alligators

Slide59

Crocodiles and Alligators

Slide60

Order Crocodilia: Crocodiles and Alligators

Crocodiles are known to attack large prey

like

cattle, deer

, and

even people

.

Alligators are less aggressive

and

seldom attack people

.

Slide61

Order

Crocodilia

: Crocodiles and Alligators

Crocodilians

lay their eggs

in

dead vegetation

or in the

sand

and

guard the nest

. When the

eggs hatch

, the

babies cry out

to the

mother

and

she digs them out

.

After she digs them out,

she delicately places them in her mouth

and

carries them safely to water

.

Soil temperatures determine the gender

of the young the

same way as turtles, except

in crocodilians,

low soil temperatures produces females

and

high soil temperatures produces males

.

Slide62

Crocodilian Parental Care