Vertebrates share the characteristic of having a notochord or backbone at some point in their development. The backbone provides support, protection, and structure to the body. It allows vertebrates like fish, birds, and mammals to move effectively through their environments. Fish specifically use gills and fins to breathe and move through water, and can be categorized into three main groups: jawless fish, cartilaginous fish, and bony fish.

1. EVERYTHING YOU ALWAYS
WANTED TO KNOW ABOUT:

2. WHAT MAIN
CHARACTERISTIC
IS SHARED
BY ALL
VERTEBRATES?

3. CHORDATE Characteristics:
At some time in life
they have:
NOTOCHORD, or
nerve cord - a rod
like structure that
supports back.

4. IF YOU SAID BACKBONE, YOU ARE
CORRECT!
VERTEBRATES ARE
MEMBERS OF THE
PHYLUM CHORDATO -
(from the name
notochord)also called
Chordates

5. Your
NOTOCHORD
is your spinal
cord - It’s the
connection
between the
brain and the
nerves

6. SOME VERTEBRATES have
backbone made of CARTILAGE
(connective tissue - softer than bone
but still strong!

7. •Backbones run
down center of
back.
•Made up of
VERTEBRAE
lined up in a row.
•Joints between
vertebrae give you
flexibility

8. EACH VERTEBRAE HAS A HOLE IN
IT THAT THE SPINAL CORD GOES
THRU - like fingers fit into rings

9. COW
BACKBONE
FISH

10. The backbone is part of the
ENDOSKELETON (internal
skeleton). It’s job:
•SUPPORT
•PROTECT
•GIVES BODY SHAPE
•A PLACE FOR MUSCLES
TO ATTACH

11. Endoskeleton also includes the
skull(protects brain as u see in my
picture), ribs(protects organs),
arm and leg bones (help you
move)..but YOU already knew
that!

12. How can you tell the difference between
types of vertebrates?
BODY TEMPERATURE
Fish, amphibians, reptiles are
ECTOTHERMS - body temp.
changes with environment.
Birds and mammals are ENDOTHERMS
- body controls temp by controlling
internal heat it produces.

13. One last fact about vertebrates:
Chordates have slits in their throat
called PHARYNGEAL
Most other
vertebrates
have their
PHARYNX pharyngeal
slits disappear
before birth.

14. PHARYNGEAL
SLITS
Fish keep these slits
all their lives as part
of their gills.

15. FISH

16. HOW DO FISH USE
THEIR GILLS?
WHAT ARE THE 3
GROUPS OF FISH?

17. FISH:
• vertebrates that live in water
•fins for movement
•ectothermic
•gills to breathe
•have scales - overlapping plates
that protect skin

18. OBTAINING O2
Fish swim along,
open their mouth
& take in H20
The H20 moves
thru mouth to
gills
GILLS: feather-like structures - red
GILLS
in color due to blood vessels in them.

19. H20 flows over gills O2 moves into blood
C02 flows out into H20

20. Like all vertebrates, fish have a closed
circulatory system. The heart pumps blood
in a loop:
HEART GILLS BODY HEART

21. MOVEMENT
FINS: thin
membrane
stretched across
bony supports

22. FEEDING
FISH have highly developed nervous
systems and sense organs to help in
capturing food and avoiding predators
Well, not like this…..more like….

23. Their eyesight is better than
yours (remember there is
less light under water)
Sharks can smell
and even taste a tiny
amount of blood - as
little as one drop- in
115 liters of water!
That is 57.5 two liter
sodas!

24. AND some fish have taste organs in
the most unusual places. Catfish
have taste organs on their whiskers!

25. FEEDING
Some fish
like the
barracuda
have sharp
teeth for
stabbing
food

26. Others, like trout have short
blunt teeth for gripping &
crushing insects

27. Filter Feeders like the Basking Shark and
Manta Ray use comb-like structures on
their gills to filter tiny plants and animals
from the water.

28. Fish Reproduction
Most fish have external
fertilization: as female
releases eggs, male
spreads a cloud of sperm
over them.
Some fish like guppies and sharks
have internal fertilization: when
the eggs are mature enough to live
on their own, female gives birth.

29. Biologists classify fish into 3
groups:
Jawless Fishes
•Bony Fishes
•Cartilaginous Fishes
They are grouped according to their mouth
structure and type of skeleton

30. JAWLESS
FISH

31. Jawless Fish
•No scales
•skeletons made of
cartilage
•one fin (no pairs of
fins)
•jawless mouth Lampreys are eel shaped
parasites-use sharp teeth
scrapes, stabs and and suction-cup mouth to
sucks to get food feed

32. CARTILAGINOUS
FISH

33. CARTILAGINOUS FISH
Sharks, Rays, Skates
•Skeletons made of cartilage
•Have jaws and pairs of fins
•Pointed, tooth-like scales cover bodies -
rougher than sandpaper
•Carnivores
•Rays and Skates live on ocean floor - filter
feeders - east mollusks, crustaceans, small
fishes

34. CARTILAGINOUS FISH -
Sharks
•Streamlined bodies for quick movement
•Mouth on bottom part of head
•Jagged teeth arranged in rows - 1st
couple rows are for feeding - remaining
rows are replacement teeth. If a tooth is
lost, one from next row moves up (NO
DENTURES EVER NEEDED!)
Sharks

35. SHARK TEETH ROWS

36. CARTILAGINOUS FISH -
Sharks
•Swimming or currents move water
over gills
•Spend most of time hunting for food -
will attack anything that smells like
food.
•Poor eyesight - that is why they
swallow strange objects at times.

37. BONY FISH

38. BONY FISH
Most familiar fish are bony fish:
trout, tuna, flounder, salmon,
goldfish, etc.
•Covered with scales
•Pocket on each side of head that
holds gills - flap over gills opens to
release water

39. BONY FISH
Swim Bladder and Buoyancy
Fish neither sink or float. They have an
organ called a SWIM BLADDER - sac that
stabilizes body at different depths. It
contains O2, nitrogen & CO2...

40. Swim Bladder and Buoyancy
...if the gas is less the fish sinks lower - if it
is more the fish moves higher in the water.
The change in the gas volume affects the
Buoyancy Force - force that water exerts
upward on any underwater object
LESS
THINK BALLOONS!
MORE

41. Bony Fish Diversity
•Make up 95% of all fish species
• Live in salt and fresh water
•Some live in deep water and some in
shallow