Vertebrates
Phylum Chordata Review
Phylum Chordata = Vertebrates
• All chordates have a notochord, dorsal nerve
cord, pharyngeal pouches, & a postanal tail at
some point in its life
• Also have bony or cartilage vertebrae (spine),
a cranium, and an endoskeleton
Major Groups of Vertebrates:
1. Lampreys & Hagfish – no jaws
2. Sharks, Rays, & Skates – cartilage endoskeleton
3. Bony Fish – bone endoskeleton
4. Amphibians – frogs, toads, salamanders,
caecilians
5. Reptiles – turtles, lizards, snakes, alligators,
crocodiles
6. Birds – feathers & hollow bones for flight
7. Mammals – hair, mammary glands, give birth
Chapter 30: Fish & Amphibians
Section 30-1: Fish Body
I. Basic Characteristics
1.
2.
3.
4.
5.
Bilateral Symmetry
Endoskeletons
Gills
Closed-loop Circulation
Kidneys – filters water & waste from blood &
makes urine
II. Movement & response – built to swim!
A. Endoskeleton
1. Few only have small pieces of cartilage along
the dorsal nerve cord.
2. Most have a complete endoskeleton of either
cartilage or bone.
B. Fins & Swim Bladder
1. Fins are used to stabilize, turn, dive, climb, &
move in all directions.
2. Swim Bladder – gas-filled sac used to control
bouyancy
C. Sensory Organs
1. Lateral Line – canals in the skin lined with cells
sensitive to vibration & pressure in the water
III. Respiration & Circulation
A. Respiration
1. Water passes over gills, which are made of
rows of filaments through which gases are
exchanged
2. Water then leaves through a gill slit, an
opening at the back of the cheek
B. Circulation
1. Single chamber-pump heart
2. Single-loop circulation
IV. Reproduction
A. External Fertilization
1. Spawning – both male and female gametes
are released near each other for fertilization
2. Produces millions of fertilized eggs, but most
are eaten (& the hatchlings).
B. Internal Fertilization
1. Sharks & rays fertilize eggs in female’s body
2. Young are then born after eggs develop inside
female
Section 30-2: Groups of Fish
I. Jawless Fish (Class Agnatha)
A. Basic Characteristics
1. Cartilage Skeletons
2. Retain notochord into adulthood
3. No backbone
B. Hagfish
1. Scavengers & predators
2. Produce lots of slime to suffocate predators
C. Lampreys
1. Parasitic – feed on blood & body fluids
II. Cartilagenous Fish (Class Chondrichthyes)
A. Basic Characteristics
1. Paired fins & jaws
2. Skeletons of cartilage & calcium carbonate
B. Sharks
1. Teeth are modified scales, arranged in 6-10
rows
2. Teeth are constantly growing and replacing
lost ones (one shark = 20,000 teeth in a
lifetime)
C. Skates & Rays
1. Flattened bodies & teeth for crushing prey or
grazing plankton
2. Some rays discharge an electrical shock to stun
prey or ward off predators
III. Bony Fish (Class Ostheichthyes)
A. Basic Characteristics
1.
2.
3.
4.
5.
Skeleton completely made of bone
Lateral lines
Operculum – hard plate to cover the gills
Swim bladder to regulate buoyancy
Paired fins for high maneuverability
B. Ray-finned Fish
1. Most fish have fins supported by rays of bone
C. Lobe-finned Fish
1. Fins are fleshy & muscular
2. Only 7 species exist today: 1 coelacanth, 7 lungfish
3. Probably gave rise to amphibians
Ray-Finned Fish
Section 30-3: Amphibian Body
• Class Amphibia = means “double life”
• Amphibians probably evolved from lobefinned fishes
• First known amphibian is called Ichthyostega,
which is about 370 million years old.
I. Basic Characteristics
1. Most have an aquatic larval stage and change
(metamorphosis) to a terrestrial adult
2. Have moist skin with no scales
3. Feet, if present, lack claws and are webbed
4. Most use gills, lungs, and skin to respirate
5. Double-loop circulation with 3-chambered
heart
6. Eggs lack shells, laid in water, & fertilized
externally
II. Body Systems
A. Movement & Response
1. Endoskeletons specialized for jumping,
landing, & walking
2. Well-developed sense organs
• Nictitating Membrane – transparent,
movable membrane over eyes (moistens)
• Tympanic Membrane - eardrum
B. Respiration
1. Larva use gills and skin
2. Adults use either lungs (pulmonary respiration)
or skin (cutaneous respiration)
3. Mucous Glands – produces a lubricant to keep
skin moist fro respiration
• Other glands may produce a foul-tasting or
poisonous substance
C. Circulation
1. 3-chambered heart
• 2 top atria are separated by a muscular
wall called the septa
• 1 bottom ventricle pumps blood to the
lungs & the body
• Spiral Valve – divides the conus arteriosus
so that most of the O2-poor blood is
diverted to the lungs & most of the O2–rich
blood is diverted to the body
2. Pulmonary Circulation – carries deoxygenated
blood from the heart to the lungs, then back
to the heart
3. Systemic Circulation – carries oxygenated
blood from the heart to the body and back to
the heart
D. Digestive System – includes pharynx,
esophagus, stomach, liver, gallbladder,
pancreas, small & large intestines
E. Excretory System – 2 kidneys, on either
side of the spine, filter wastes out of blood
and is flushed out as urine
Frog Anatomy
Section 30-4: Groups of Amphibians
I. Order Urodela – salamanders
1. Elongated bodies, tails, most have 4 legs, moist
skin
2. External fertilization usually
• Internal fertilization in some where female
picks up a sperm sac and places it in her body
3. Lay eggs in water or moist places
4. Young resemble adults except they have gills
that will be lost as the undergo metamorphosis
II. Order Apoda – without legs or appendages
1. Commonly called Caecilians
2. Are rarely seen because they live in the soil or in
water of tropical areas
3. 0.3 – 1.2m long
4. Eyes are small and under the skin = blind
5. Tentacle on the side of the head senses
chemicals given off by prey
6. Internal fertilization
7. Some lay eggs, a few give live birth
III. Order Anura – frogs and toads
1.
2.
3.
4.
5.
Body is adapted for jumping
Uses sticky tongue to snatch prey
Adults are tailless and larva (tadpoles) have tails
External fertilization in the water (usually)
Toads have squat bodies and shorter legs than
frogs. Also have skin covered in bumps.
Sections 31-1 & 31-2: Class Reptila
I. Characteristics
A. Basics
1. Live completely on land due to having an egg
that doesn’t dry out and a body covered with
scales made of keratin
2. Lack feathers or hair; clawed feet
3. Ectothermic metabolism = cold-blooded
B. Movement & Response
1. Strong endoskeleton of bone
2. Legs are jointed on the side, so reptiles are slower
than mammals
3. Claws for climbing, digging, & short bursts of speed
4. Excellent eye sight
5. Lack a tympanic membrane; feel vibrations through
jaw bones
6. Jacob’s Organ – on roof of mouth; sensitive to
odors
C. Ectothermic – cannot generate their won
body heat with their metabolism
1. Bask in the sun for warmth or shade to cool
down
2. In cold temperatures, reptiles slow down or even
stop. Reptiles are limited to warmer climates.
II. Respiration & Circulation
A. Lungs
1. Have a large amount of surface area for
maximum gas exchange
B. Heart
1. Almost 4 chambers: 2 top atria & 2 ventricles
with an incomplete septum dividing the
ventricles
2. This makes the reptile heart better at separating
oxygen-rich blood from oxygen-poor blood than
amphibians.
III. Reproduction
A. Internal Fertilization
1. Many are oviparous – mother lays eggs
outside her body & young hatch later
2. Some are ovoviviparous – fertilized eggs
remain inside female & usually hatch still inside
B. Amniotic Egg – contains water & food supply
1. Shell makes egg watertight
2. Albumin (egg white) – protects/cushions embryo
& nourishes it
3. Four specialized membranes maintain embryo
• Amnion – cushions embryo in watery
environment
• Yolk sac – embryo’s main food source
• Allantois – stores waste & exchanges gases
• Chorion – allows oxygen into egg & CO2 out
Amniotic Egg
found in reptiles, mammals, and birds
IV. Groups of Reptiles
A. Order Testudines – turtles & tortoises
1. Have hard shell with their spine fused to the top
• Carapace – top portion of shell
• Plastron – bottom portion of shell
2. Tortoises live on land; more domed carapace
3. Turtles live in water; more streamlined carapace
B. Order Sphenodontia – tuataras
1. Only 2 living species, native to New Zealand
2. More active at lower temperatures
3. Have a third “eye” or Pineal organ that controls
seasonal biological rhythms and body temperature
4. Have survived unchanged for 150 million years
C. Order Crocodillia – alligators & crocodiles
1. Aggressive carnivores
2. Eyes & nostrils on top of snout so they can see
while submerged
3. Have a valve at the back of the throat to prevent
water from entering while attacking prey
4. Unlike other reptiles, they care for their young
D. Order Squamata – lizards & snakes
1. Both undergo molting & have a loosely attached
jaw for eating whole prey
2. Lizards include iguanas, geckos, anoles, & horned
lizards
3. Snakes swallow prey whole, many are constrictors,
some inject venom (specialized salivary glands) with
fangs in the back of the mouth, & most lay eggs
Section 31-3 & 4: Class Aves (birds)
I. Characteristics of Birds
A. Have retained some reptilian
characteristics
1. Lay amniotic eggs
2. Legs & feet are covered in scales
B. Unique to Birds
1.
2.
3.
4.
5.
Feathers & wings
Lightweight endoskeleton
Endothermic metabolism = warm-blooded
Lungs with air sacs
Beak – tough, horny sheath covering jaws, no
teeth
C. Body Temperature & Control
1. Endothermic – can generate enough heat
through metabolism to maintain a high body
temperature
2. Body temperature range: 40oC – 44oC (104oF –
111oF)
3. High temperature is maintained by a fast
metabolism & is needed for flight
II. Adaptations of Birds
A. Feathers – made of keratin
1. Contour feathers – cover adult’s body
• Flight feathers - on wings & tail; provide lift
• Barbs – branches within a feather that provide
a smooth surface & a study, flexible shape
2. Down feathers – covers body of young birds &
found beneath adult’s contour feathers
• Trap warm air, conserves heat
B. Lightweight Endoskeleton
1. Bones are thin & hollow
2. Many are fused to provide a from for flight
muscles
3. Have a keeled breast bone & fused collar bones
(furcula) to support breast muscles
C. Beaks & Feet
1. Beaks are adapted to the bird’s diet/available
food source
2. Feet are adapted to habitats, lifestyles, & diet
III. Respiration & Circulation
A. Lungs
1. Air passes over lung’s surface in one direction &
air sacs are holding tanks for air
• Lungs are only exposed to fresh, oxygen-rich air
• Blood flows in opposite direction, increasing
oxygen absorption
B. Four-Chambered Heart
1. Two ventricles are completely separated (oxygenrich blood doesn’t mix with oxygen-poor blood)
2. High heart rate to pump large amounts of oxygen
to muscles for flight
IV. Reproduction
A. Internal fertilization
1. Male bird presses cloaca to female’s cloaca &
releases sperm
2. Female lays one or a clutch of eggs (oviparous)
B. Care for their eggs & young
V. Groups of Birds
A. Terrestrial Birds
1. Perching Birds – goldfinches, cardinals, robins, etc.
2. Birds of Prey – keen vision & talons; eagles, hawks,
owls, vultures, falcons, etc.
3. Flightless birds – ostriches, emus, etc.
B. Aquatic Birds
1. Diving Birds – penguins, loons
2. Water Birds – swans, geese, ducks
3. Wading Birds – herons, storks, flamingos, egrets
Chapter 32: Class Mammalia
I. Key characteristics
A. Hair
A. Insulation
B. Color can be used for camouflage
C. Advertising – warning predators or
competitors; attracting a mate
D. Whiskers – specialized hairs sensitive to touch
B. Endothermy
1. Respiratory system
• Lungs have large internal surface area for high
rates of gas exchange
• Aided by a diaphragm, a muscle that helps
lungs expand & fill with air
2. Circulatory System
• 4-chambered heart
• Oxygen-poor blood is always sent to the lungs
while oxygen-rich blood is always sent to
body tissues
C. Teeth
1. Specialized among mammals to meet different
dietary needs (herbivore vs. carnivore)
2. Usually, mammals have 2 sets of teeth in their life
3. 4 Types of Teeth
• Incisors – front teeth; biting & cutting
• Canines – stabbing & holding
• Premolars & Molars – crushing & grinding
D. Nervous System
1. Brain is 15 times larger than other vertebrates
2. Mammals depend on all 5 senses for survival
3. Echolocation – emit high frequency sound waves,
which bounce off objects & return
• Determines size, distance, direction, & speed
of objects
II. Parental Care
A. Mammary Glands
1. Unique to all mammals
2. Produce milk for nourishing young after birth
B. Monotremes - oviparous
C. Marsupials – embryo is born after a few days
or week
D. Placental Mammals – embryo completes
development inside mother
III. Orders of Mammals
A. Order Monotremata – monotremes
1. Only found in Australia & New Quinea
2. Lay eggs that hatch
3. Like reptiles, have a cloaca, a common
passageway for the digestive, reproductive, and
urinary systems.
4. Do have hair & mammary glands
5. Platypus & Echidnas (spiny anteater)
B. Order Marsupialia – marsupials
1. Deliver embryo early, & embryo continues
development in a pouch where they grow & nurse
2. Found in Australia, S. America, & 1 species in N.
America
3. Kangaroos, wallabies, gliders, opossums,
wombats, koalas, Tasmanian devil
C. Placental Mammals
1. A placenta attaches the fetus to the mother &
allows the exchange of nutrients, oxygen, &
wastes.
2. Fetus develops in mother’s uterus
3. Very diverse and includes many Orders. See pg.
793-795.