Transcript Amphibian

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Aquatic Life –
Amphibians & Reptiles
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In this unit we will continue to discuss
the characteristics of aquatic animals
categorized as vertebrates (animals
with backbones) and focus on
amphibians and reptiles.
Summaries = Orange
Underlined = Vocabulary
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Kingdom Animalia
◦ Phylum Chordata
 Subphylum Vertebrata (animals that
have backbones)
◦ Superclass Tetropoda (organisms with four
limbs)
 Class Amphibia
 Class Reptilia
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Review of Taxonomy
The word amphibian
means “double life”
because these
animals live both in
water and on land.
 As larva, amphibians
live in water and
respire using gills.
 As adults, amphibians
are terrestrial (live
on land) and breath
using lungs.
 They characteristically
have moist skin and
lack scales and claws.
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http://www.dnr.state.md.us/wildlife/art/tadpole-to-frog.gif
What is an Amphibian?
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http://upload.wikimedia.org/wikipedia/commons/thumb/8
/87/Bufo_periglenes1.jpg/300px-Bufo_periglenes1.jpg
They have moist
skin that enables
the exchange of
gases with the
environment
(inefficient lungs).
Their skin must stay
moist to allow for
the diffusion of
gases.
They have mucus
glands in the skin
that aid with staying
moist.
Amphibian - Respiration
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Amphibians
have a
doubleloop
circulatory
system and
a 3chambered
heart as
adults.
Amphibian - Circulation
Amphibians use external fertilization for
reproduction.
 They are oviparous and lay eggs that are
coated with a jelly-like coating to protect and
provide embryos with nourishment.
 Amphibians must lay their eggs in water or
moist places on land so eggs do not dry out.
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http://www.rodmorris.co.nz/images/reptiles1/gallery1.jpg
Amphibian - Reproduction
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Amphibians have a cloaca or a common
chamber for the digestive, excretory and
reproductive systems.
The products (urine, eggs, etc) leave the
body through the cloaca.
http://sps.k12.ar.us/massengale/images/frog_d5.gif
http://courses.washington.edu/vertebra/452/
photos/amphib/newt_cloaca.jpg
Amphibian - Excretion
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http://www.amonline.net.au/wild_kids/images/freshw
ater/bellfrog_illus.jpg
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Amphibians are the
only vertebrate
grouping that have a
life cycle that includes
metamorphosis (a
series of changes
between larvae and
adult).
Many insects
(invertebrates) exhibit
metamorphic changes
EX The Butterfly
The stages are
triggered by the
hormone thyroxin.
Amphibian - Metamorphosis
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Amphibians have a
transparent
nictitating
membrane which
helps to keep eyes
moist in air and
protected in water.
Tympanic
membranes in
amphibians allow
the animals to
detect sound waves
in air or water
(primitive ears) and
are found behind
the eyes.
http://www.hsu.edu/uploadedImages/Biology/toad%20
nictitating%20membrane200.jpg
http://www.infovisual.info/02/026_en.html
Amphibian – Adaptations for Water
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http://www.ryanphotographic.com/imagesFROG%2020%20Yell
ow%20banded%20poison%20dart%20frog.jpg
Order Anura
includes all
frogs and toads
(have ability to
jump).
◦ Frogs have
smooth, moist
skin
◦ Toads have
dry, bumpy
skin and are
Toads have
adapted to
living in drier
environments
http://www.casarioblanco.com/poison-dart-frog.html
Order Anura – Frogs & Toads
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Order Urodela includes salamanders.
This order has a long tail, long body and two
pair of legs almost equal in size.
Some salamanders have gills, some have
lungs, some have both.
http://www.tomuphoto.com/reptiles/images/cave%20salama
nder.jpg
Order Urodela – Salamanders
Order Apoda or
caecilians have
characteristics
that make them
look like
segmented
worms.
 These legless
amphibians are
blind or nearly
blind and spend
their life
burrowing
through soil (in
moist tropical
regions).
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http://www.omahazoo.com/home/images/caecilian.jpg
Order Apoda – Wormlike Amphibians
Between 240 and 150
million years ago, giant
reptiles ruled the earth.
The dinosaurs eventually
died off, but their relatives
are alive today.
 A reptile is characterized
as a vertebrate that has
dry, scaly skin, breaths
with lungs, and lays
terrestrial eggs.
 Today reptiles inhabit large
areas of the earth but they
cannot live in very cold
areas as they are
ectothermic.
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http://www.usao.edu/~facshaferi/sue2.jpg
What is a Reptile?
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Reptiles have tight-fitting, water-resistant
scales made of keratin.
Scales prevent water loss from body but do
not grow with body so must be shed
periodically.
Presence of large, strong, legs or limbs close
to body quickly on land and in water.
Found only on the
Galápagos Islands, marine
iguanas often wear
distinctive white "wigs" of
salt expelled from glands
near their noses.
Photograph by Rob
Stewart/Animals Animals—
Earth Scenes
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Reptiles are respire using reptiles
have well-developed lungs.
Aquatic reptiles are well adapted to
remain submerged underwater for
long periods of time.
A hawksbill turtle swims
just above the seafloor
with flippers spread like
wings. Hawksbills get their
name from their tapered
heads, which end in a
sharp point resembling a
bird's beak.
Photograph by Nick
Caloyianis
Reptile – Respiration
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Reptiles have a partially divided, 3-chambered
heart (except crocodiles which have a 4chambered heart).
This allows for greater separation of oxygen-rich
and oxygen-poor blood.
Nile crocodiles are the
largest crocodilians in
Africa, sometimes
reaching 20 feet (6
meters) long.
Photograph by Chris
Johns
Reptile – Circulation
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Reptiles have internal
fertilization with shelled,
terrestrial (can be laid on
land) eggs (oviparous)
which eliminates
dependence on water for
fertilization.
They have a higher rate of
fertilization because sperm
are protected from the
environment.
Females do not need to lay
as many eggs.
An amniotic egg provides
nourishment and protection
for developing embryo (yolk
is food source).
http://www.naturealmanac.com/archive/hatch
ing_reptile/clutch_of_eggs.jpg
Reptile - Reproduction
Unlike other sea turtles, female Kemp's ridley turtles
come ashore to lay their eggs in the daylight hours.
Photograph by Bill Curtsinger
Video
http://www.infovisual.info/02/020_en.html
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Reptile - Excretion
Kidneys
filter and the
digestive
system
collect
wastes to be
excreted
from the
body.
Their
excretory
system is
designed to
conserve
water with
urine that is
thick and
pasty.
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http://dreyfus.ib.usp.br/bio435/bi
Order Sphenodonta
o43597/vanessa/chave/tua.jpg
The only surviving member of this order is the
Tuatara, an endangered lizard found on the
islands of New Zealand.
Known as a "living fossil" - they have survived
unchanged for 150 million years!
They have a unique third eye to detect heat.
Order Sphenodonta
Order Testudines, or
turtles & tortoises,
which all have a
protective shell fused
to their vertebrae.
 Tortoises (live on
land)
 Freshwater turtles
(live on land but feed
in the water)
 Sea turtles (live in the
ocean)
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http://www.rowanpix.com/herps/images/
galap_tortoise.jpg
Order Testudine - Turtles
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Order
Squamata or
lizards & snakes
Snakes have
lost their legs to
increase
mobility.
Historically
snakes had legs,
but still have hip
bones and a
femur.
Lizards have
legs, claws toes,
external ears,
and movable
eyelids.
Green Anaconda – South America
Photograph by Claus Meyer/Minden
Pictures
Order Squamata – Lizards & Snakes
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Order Crocodilians or crocodiles and alligators.
Adapted to hunt with eyes and nostrils above the
head so the body can remain submerged when they
attack.
Crocodiles have a narrow head and long snout; live
in tropical regions all over the world.
http://worldanimalfoundation.homestead.com/000802_c448_0087_csls.jpg
Order Crocodilian – Crocs & Alligators
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Alligators have a short, broad snout; live in
tropical regions of China and USA.
They are the only reptile group that takes care of
their young.
Female crocs lay
their eggs in
clutches of 20 to
60. After the eggs
have incubated for
about three
months, the
mother opens the
nest and helps her
young out of their
shells.
Photograph by
Steve Winter
Video