Transcript Vertebrates

Vertebrates
Fishes
 All fishes are ectotherms.
 Ectotherms- animals with body
temperatures dependent upon
the temperature of their
surroundings.
 Fish have a two chambered
heart and breath through gills.
 Different types of fishes are
grouped into three different
classes, jawless fishes,
cartilaginous fishes and bony
fishes.
Fishes cont. Jawless Fishes
 Types of jawless fishes are lampreys and
hagfishes.
 Jawless fish have endoskeletons made of
cartilage like sharks and types of rays.
Fishes cont. Cartilaginous fishes
 Types of cartilaginous fishes are
sharks, skates and rays.
 Evidence has proven that jaws were
first evolved in this type of fish.
 Cartilaginous fish have
endoskeletons made of cartilage
like jawless fish.
 Cartilaginous fish have paired fins
and a lateral line system that
enables them to detect movement
and vibrations in water.
Fishes cont. Bony Fishes
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Most fishes belong to the bony fish
class.
All bony fishes have a bony
skeleton, gills, paired fins, flattened
bony scales and a lateral line
system.
Bony fishes breath by drawing in
water into their mouth then
passing it over the gills where gas
exchange occurs.
They adjust their depth in the
water by regulating the amount of
gas that diffuses out of their blood
into the swim bladder.
Amphibians
 Amphibians are ectothermic with three chambered hearts, lungs
and thin moist skin.
 Most gas exchange is carried out through the skin not the lungs.
 Adult amphibians live on land but rely on water for reproduction.
 Almost all amphibians go through the process of metamorphosis.
 Metamorphosis- which the young hatch into tadpoles, then
gradually lose their tails and gills as they develop legs, lungs and
other adult structures.
 Amphibians can be classified into three orders Anura, Caudata and
Apoda.
Amphibians cont.
 Anura are considered to be frogs
and toads.
 Anuras have vocal cords that can
produce wide range sounds.
 Frogs have think, smooth, moist skin.
 While toads have thick bumpy skin
with poison glands.
 Caudata are considered to be
salamanders and newts.
 Salamanders have long, slender
bodies with a neck and tail.
 Apoda are considered to be
legless caecilians.
 Caecilians have long, wormlike
bodies with no legs.
Reptiles
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Reptiles are ectotherms with dry, scaly skin
and clawed toes.
Types of reptiles are snakes, lizards, turtles,
crocodiles and alligators.
All reptiles have four legs that are positioned
under the body except snakes.
Most reptiles have a three chambered heart
except for a crocodile it has a four
chambered heart.
The scaly skin of reptiles reduces the loss of
moisture on land scales also prevent the skin
from absorbing or releasing gas.
Reptiles are dependent on lungs for the
essential gas exchange.
Reptiles lay amniotic eggs to reproduce.
Birds
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Birds are the only class of animals to
have feathers.
Feathers are lightweight, modified
scales, that help insulate birds and
enable them to fly.
They have wings which are modified
forelimbs.
Similar to reptiles birds have scales on
their feet and clawed toes.
Unlike reptiles they are endotherms.
Endotherms- animals that maintain a
constant body temperature.
Endotherms must eat frequently to
provide energy needed for producing
heat.
Birds cont.
 Birds have thin hallow bones with
cross braces that provide support
for strong flight muscles while
reducing their body weight.
 Birds have a four chambered
heart.
 Birds have a unique respiratory
system which oxygen is available
through exhalation and
inhalation.
 Like reptiles birds lay amniotic
eggs but unlike reptiles birds
incubate their eggs in nests. The
nest keeps the egg warm till the
young birds hatch.
Mammals
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Mammals are endotherms.
Mammals are named after their
mammary glands, which produces
milk to feed their young.
Most mammals have hair which is
used to help insulate their bodies and
sweat glands that help keep them
cool.
Mammals need a high energy level
for maintaining body temperature
and high speeds of locomotion.
Mammals have a efficient four
chambered heart and muscular
diaphragm beneath the lungs to help
deliver oxygen for their activities.
Mammals cont.
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All mammals have internal fertilization and the young begin development inside the
mothers uterus.
Mammals are divided into three large groups monotremes, marsupials and placental.
Monotremes are mammals that lay eggs.
Marsupials are mammals which the young complete a second stage of development after
birth in a pouch made of skin and hair on the outside of the mothers body.
Placental mammals carry their young inside the uterus until development is nearly
complete.
Mammals can also be classified by their teeth, how many they have and type.
Types of teeth are incisors, canines, molars and premolars.
Incisors are used to cut food.
Canines are long pointed teeth used to stab or hold food.
Molars or premolars have flat surfaces with ridges and are used to rind and chew food.