Transcript Vertebrates I Chordates, Fishes, & Amphibians

Vertebrates I
Chordates, Fishes, &
Amphibians
Chordate
Phylum Chordates
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All have notochords:
-Chordata means long, rod-like
structure called notochord
-Develops into a backbone during
embryo stage
Nerve Cord
Have nerve cord:
-dorsal nerve cordbundle of nerves
that lies above the
notochord
In adults posterior
portions develop
into spinal cord
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Have Gill Slits & Muscle Blocks
Gill pouches are
paired located in the
pharynx behind the
mouth
 As adults, use to
strain food from the
water
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Consist of stacked
muscle layers
 Can see
 Aids in movement of
the tail
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Body Plan
Notochord
Dorsal hollow
nerve cord
Anus
Muscle
blocks
Mouth
Pharyngeal
pouches
Postanal
tail
Sea Squirts
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Also called tunicates
1250 species that live in
the ocean
Most adults sessile
Invertebrate Chordata
If you remove one from
its colony-it might squirt
out a jet of water
Lancelets
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Small streamlined,
marine animal-usually 5
cm long
Spends most of their
time buried in the sand
with only their heads
sticking out
Filter feeders
Invertebrate chordata
Fishes
Fishes, like all vertebrates, are classified
in the phylum Chordata.
All Chordates have 3 traits in common:
1. Notochords 2. Gill Slits 3.Dorsal Nerve
cord
All vertebrates are bilaterally symmetrical,
coelomates that have endoskeletons, closed
circulatory systems, nervous systems with
complex brains and sense organs, and
efficient respiratory systems.
Fishes Breathe using Gills
Fishes have gills made up of feathery gill filaments
that contain tiny blood vessels.
Gill Filaments
Fishes breathe using gills
As a fish takes water in
through its mouth, water
passes over the gills and
then out through slits at the
side of the fish.
Gill Filaments
Water
Capillary networks
in filament
Artery
Vein
Water
Gill
filaments
All Fish have 2 chambered
hearts
Fishes reproduce sexually
Most fish have
external fertilization
& development
called SPAWNING
 All fish reproduce
sexually
 Eggs and sperm can
be released directly
into the water, or
deposited in more
protected areas,
such as on floating
aquatic plants.
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Fishes reproduce sexually
Cartilage fish have
internal fertilization
 Skates deposit
fertilized eggs on
the ocean floor.
 Some female sharks
and rays carry
developing young
inside their bodies.
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Most fishes have paired fins
The paired fins of fishes foreshadowed the
development of limbs for movement on land and
ultimately of wings for flying.
Fins
are fan-shaped membranes that are used
for balance, swimming, and steering.
Pectoral
fin
Dorsal
fins
Anal
fin
Caudal
fin
Pelvic
fins
Fishes have developed
sensory systems
Cartilaginous and bony fishes have an adaptation
called the lateral line system that enables them to
sense objects and changes in their environment.
Lateral line
Gelatin-like fluid
Receptor cells
Nerve
Jaws evolved in fishes
Gill arches
Gill slits
Jawless, filter-feeding fish
Skull
Gill slits
Gill arches
Beginning of jaw formation
Fish with jaws
Jaws also allowed early fishes to prey on a greater
variety of organisms.
Jaws
Swim Bladders
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Fish use a swim
bladder to maintain
buoyancy in the
water.
Most fish have scales
Sales are thin bony
plates formed from
the skin.
4 types of scales.
 1. Tooth-like Scales
2.
Diamond-shaped
Scales
3.
Cone-Shaped
Scales
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4. Round Scales
Bony Fish Swim in 1 of 3 ways
An eel moves its
entire body in an
S-shaped pattern.
A mackerel flexes
the posterior end
of its body to
accentuate the tail
-fin movement.
A tuna keeps the
body moving it’s
powerful tail. Fishes
that use this method
move faster than all
others.
DIVERSITY OF FISHES
Agnatha: Lamprey & Hagfish
“Jawless Fish”
 Called Roundmouths
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Breath using gills made
of feathery gill filaments
containing blood vessels
Separate sexes
Reproduce sexually
2 chambered hearts (1st
chamber receives blood
& 2nd pumps blood to
the gills
Agnatha:
Lamprey
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Are adapted for
sucking the blood &
body fluid of other
fish by attaching to
a fish by suction,
tearing a hole in the
fish with it’s toothy
tongue, & secreting
a chemical to keep
the fish’s blood from
clotting.
Agnatha:
Hagfish
Are bottom dwellers
in cold waters.
 Scavengers of dead
& dying fish on the
ocean floor
 Saw’s a hole in the
fish with it’s toothy
tongue & eats them
from the inside out.
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Chondrichthyes: Sharks,
Skates & Rays
Skeletons composed
entirely of cartilage
 Paired fins
 Fins used for
balance, swimming,
& steering
 275 species of
sharks, rays &
skates
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Sharks
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Reputation as killers
Swim side-to-side
Mouth has 6 to 20
rows of back-ward
pointing teeth
3,000 teeth
A shark will go
through 20,000
teeth in it’s life.
Fish are friends-not food
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http://www.youtube.com/watch?v=JV1
FAua9_Xw
Types of Sharks
Black Tip Reef Shark
Blue Shark
Great White Shark
Nurse Shark
Hammerhead Shark
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unlikely to attack
people, but
considered dangerous
due to its predatory
nature and its size
eyes and nostrils are
far apart, giving it a
"hammerhead"
appearance and
allowing the shark to
extend the range of its
senses.
Whale Shark
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biggest shark and
biggest fish
it isn't a whale (whales
are mammals, not
fish)
grow to 45 feet long
and 30,000 pounds,
but average about 25
feet long
filters plankton from
the water using "gill
rakers"
Talking Whale
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http://www.youtube.com/watch?v=B4S
URhza6_s&feature=related
Rays & Skates
Have flatten bodies
with wing like fins &
whip like tails
 Rays have
diamond/disked
bodies mostly
triangular
 Primarily bottom
dwellers.
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Osteichthyes: Bony Fish
Majority of the
world’s fish belong
to this class
 Have skeleton, gills,
paired fins, & highly
developed sense
organs
 Have swim bladders
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3 Subclasses of Bony Fish:
1.
Lobe-finned Fish:
have paddle-like
fins
Thought to be
extinct for more
than 70 million
years until a South
African fisherman
caught one in
1938.
3 Subclasses of Bony Fish:
2.
Lungfish: have
both gills and lungs
One type burrows
in the mud &
breathes with lungs
when the streams
are dry
3 Subclasses of Bony Fish:
3. Ray-finned fish:
have fins that are
supported by long
bones called
rays
Most familiar fish:
EELS, YELLOW PERCH,
HERRING &
LANTERN FISH
Moray Eel
Lantern Fish
Herring
Amphibians
Amphibians:
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Defined as
vertebrates that are
aquatic as larvae &
terrestrial as adults
What is an amphibian?
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Fertilization in most
amphibians is external, and
water is needed as a medium
for transporting sperm.
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During am plexus the
female discharges eggs -usually into water -- while
the male sheds sperms
over the eggs.
Reproduction
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Amphibian eggs
lack protective
membranes and
shells and must be
laid in water or
other moist areas.
Metamorphism
Differences:
Frogs:
- Lungs
- Legs
- 3 chambered
heart
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Tadpoles:
- Gills
- Tail
- 2 chambered
heart
Metamorphism
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Completely terrestrial salamander species
do not have a larval stage; the young hatch
as smaller versions of adults.
Amphibians are Ectotherms
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An ectotherm (EK tuh thurm) is an animal
that has a variable body temperature and
gets its heat from external sources.
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Frogs and toads also have vocal cords that
are capable of producing a wide range of
sounds. Vocal cords are sound-producing
bands of tissue in the throat
The frogs
teeth
If you look along the edges of
the frog's mouth, you will see
the maxillary teeth. Are they
found on both the upper and
lower jaws?
Vomerine Teeth are the two
small teeth located in the roof of
the mouth used for crushing
food.