Chapter 5: Vertebrates
What is a Vertebrate?
What is a vertebrate?
• Animals with backbones.
• Only about 5% of animal species.
• Endoskeleton: internal support system that
grows along with the animal.
• Muscles, digestive system, respiratory system,
circulatory system, and nervous system.
What is a vertebrate?
• Named for specialized bones called vertebrae,
also known as the backbone.
• We will be learning about fish, amphibians,
reptiles, birds, and mammals in this chapter.
Chapter 5: Vertebrates Chordates
Fish
Most vertebrates are fish.
• More than 20,000 species.
• Live in nearly all aquatic environments.
• They have adapted to survive many
environments.
Most vertebrates are fish.
• Most move by using muscles and
fins to push their bodies through
water.
• Most also have a swim bladder,
which allows them to regulate how
high or low they float.
• Sensory organs, including eyes.
• Lateral line: allows fish to sense
vibrations from other objects
without seeing/touching them.
Fish
Most vertebrates are fish.
• Fish remove oxygen from water
by gills.
• Made of many folds of tissue and
filled with blood.
• Water is brought in through the
mouth, pushed over the gills, and
then removed through the gill
slits.
Jawless Fish
• Most similar to the first fish on Earth.
• Simpler bodies- tube-like shape and no stomach.
• They have no jaw, but do have teeth that cannot
chew.
▫ They get food by latching onto animals and
sucking out flesh and fluids.
• Lampreys and hagfish
Jawless Fish
Cartilaginous Fish
• Sharks, rays, and skates.
• Skeletons are made of cartilage, not bones.
• Most eat small animals such as mollusks and
crustaceans.
• Rays eat by pulling animals out of the sand on
the ocean floor.
Cartilaginous Fish
Bony Fish
• Most fish (96%) are bony – tuna, flounder, eels,
goldfish, etc.
• Skeletons made of hard bones, usually covered
by bony structures called scales.
• They have jaws with teeth and several pairs of
fins.
Bony Fish
• There are several adaptations of these fish for
survival in their environments.
• In the tropics, fish are brightly colored to fit in
with the coral.
• In other areas, bright colors would draw too
much attention to the fish.
Bony Fish
Fish Life Cycles
• Most reproduce sexually.
• Female fish release eggs into the water when a
suitable male is there to fertilize them.
• After fertilization, the eggs are left on their own
(usually) to hatch.
Fish Life Cycles
• Most fish eggs are
surrounded by a soft egg case
that allows water to move
through it, giving the embryo
water and oxygen.
• The yolk provide nutrition to
the growing embryo.
• Very few eggs actually hatch
into mature fish; they are
usually eaten before they
hatch.
Chapter 5: Vertebrates
Amphibians
Amphibians
• The first group of vertebrates to live on land.
• Took millions of years for adaptations to occur
allowing this group to evolve.
• Frogs, toads, and salamanders
Amphibians
• Two pair of legs
• Lay eggs in water
• Obtain oxygen through moist skin; many have
lungs
• Sensory organs adapted for life on land.
Amphibians
• Their skin functions only when it is moist, so
they live in moist environments.
• Some are most active at night when there is
more moisture near the ground, while others live
mostly underground.
Amphibians
• Reproduce sexually.
• Female lays eggs in water, male fertilizes the
eggs, and then they are left to hatch on their
own.
• The yolk in the egg provides nutrition, and
because there is no hard covering, they can get
water and oxygen from surroundings.
Amphibians – Life Cycle
• When egg hatches, the amphibian is called a
larva.
• These are called tadpoles for frogs/toads, and
act like small fish.
▫ Gills
▫ Eat algae
▫ Move by swimming with tails
Amphibians – Life Cycle
• After a few weeks, lungs begin to develop and
the digestive system changes.
• Develops legs, loses its tail, and its head changes
shape.
• Gills stop working, tongue is used to capture/eat
small animals, and moves on to the land.
• Some stay in or near water, others move around.
• Frog Life Cycle
Chapter 5: Vertebrates
Frog Anatomy
The Frog
• Divided into a head, short neck, and trunk.
• The head contains the brain, mouth, eyes, ears,
and nose.
The head – external
• When you look at the head from the outside, you
should be able to identify the following:
• Eyes
• Mouth
• Nostrils (near mouth)
• And tympanum (ear drums)
located behind the eyes.
The head – internal
• Inside the mouth, you should see:
•
•
•
•
•
•
Teeth
Tongue
Internal nostrils (nares)
Esophagus opening
Glottis
Eustachian tube openings
The head – internal
• Inside the mouth, you should see:
The head – internal
• Inside the head, is the brain. This will be difficult
to get to.
The trunk – internal
•
•
•
•
•
•
The heart
The lungs
The kidneys
The stomach
The liver
The small/large
intestine
• The spleen
•
•
•
•
•
•
•
The pancreas
The gallbladder
The urinary bladder
The cloaca
The ureter
Fat bodies
And reproductive
organs: ovaries/
oviducts, testes
The trunk – internal
The trunk – internal
The trunk – internal
The trunk – internal
• Part 1
• Part 2
Chapter 5: Vertebrates
Reptiles
Reptiles
• Survive in hotter, drier climates.
•
•
•
•
•
Two pair of legs
Tough, dry skin covered by scales
Get oxygen through lungs
Sensory organs for land
Lay their eggs, in shells, on land
Lungs
• Born with lungs; do not use skin to take in O2.
• Takes in oxygen through mouth/nostrils and
moves it into lungs;
• Exhales carbon dioxide
Skin
• Dry and tough, covered with scales made from
keratin.
• Waterproof
• Protects from environment and predators
Eggs
• Eggs contain everything an embryo needs:
water, nutrients, gas exchange, waste storage.
• Membranes separate the internal parts, which
are covered by hard shell.
• Reproduce sexually.
• After fertilization, the hard covering forms
around each egg while still inside the female.
Eggs
• The female chooses a place on land to
lay the eggs.
• Some guard their eggs and care for
offspring once they hatch (alligators).
• Most leave their eggs to hatch on their
own.
• Once hatched, they look like small
versions of the adult.
Body Temperature – Amphibians and
Reptiles
• Ectotherms: body temps change with the
environment.
• most can move/respond more quickly when
warm, so they warm themselves in sun.
• Many can live a long time without consuming
much food.
Body Temperature
• Body stops functioning when too hot or too cold.
• Some are able to adapt to temperature by living
in certain environments.
• Most live by water, which can be used to cool
them down.
Chapter 5: Vertebrates
Birds
Birds
• About 10,000 species that live all around the
world.
• Feathers and a beak
• Four limbs – pair of legs and pair of wings
• Eggs have a hard shell
Endotherms
• Endotherm: animals that maintain a constant
body temp.
• Can stay active in colder climates because they
have adaptations for producing more body heat
from food.
▫ They need to eat a lot; birds in cooler climates
need to eat more to produce more heat.
Controlling Body Temp
• Soft feathers (down) keep warm air close to
their bodies and act as insulators.
• Other feathers, contour feathers, cover their
down and are usually water-resistant.
• Birds shiver, like humans, to generate heat.
• They can fluff their feathers to lose heat or move
to shaded areas.
Most can fly.
• Birds first appeared about 150 million years
ago, and are thought to be descendants of
reptiles with adaptations to fly.
• Most can fly – ostriches and
penguins cannot.
• Birds have many adaptations that took
millions of years for them to be able to fly:
Adaptations
• 1. Endoskeleton: some bones are fused
together without joints, making them light and
strong.
• 2. Wings/Feathers: flight feathers on the
wings are specialized for lifting and gliding;
feathers are strong to push through air.
Adaptations
• 3. Respiratory System: breathe using a
system of air sacs and lungs; oxygen is
constantly moving through the body.
• 4. Hollow Bones: many of the bones are
hollow with crisscrossing structures; provides
strength and reduces weight.
• Birds also have beaks and gizzards instead of
heavier eating structures.
Adaptations
Benefits of Flight
• Easily to see and get food.
• Migration is possible in the cooler months
Chapter 5: Vertebrates
Mammals