1
Chapter 17 Key Terms
Chordate
Endothermic
Oviparous
Ovoviviporous
Inborn Behavior
Amphibian
Hemotoxin
Ectothermic
Hemoglobin
Viviparous
Conditioned Behavior
Intelligence
Reptile
Notochord
2
Biology Chapter 17
ECTOTHERMIC VERTEBRATES
3
Phylum Chordata

Characteristics
 Dorsal
notochord
 Replaced
 All
by vertebrae in most chordates
the vertebrae form the vertebral column (supports the body)
 Dorsal
tubular nerve cord
 Vertebrae
 Pharyngeal
 Folds
surround and protect nerve cord in most chordates
pouches
of skin along the neck of chordate embryos
4
Phylum Chordata

Divided into three subphyla:

Cephalochordata
 Keep

Urochordata
 Only

their notochords throughout their entire lives
have notochord during larval stage
Vertebrata
 Usually
develop vertebral column before they are born or
hatched
5
Subphylum Vertebrata

Ectothermic
 Cold-blooded
 Rely
on heat from sources in their environment
 Amphibians,

(cannot generate its own body heat)
reptiles, fish
Endothermic
 Warm-blooded
 Uses
(generate body heat and maintain temperature)
more energy than ectothermic animals
 Birds,
mammals, humans
6
Vertebrate support

Endoskeleton
 Made
of bone and cartilage
 Support
 All

and protect the organs of the body
vertebrates have a vertebral column and skull
Two divisions of the skeleton
 Axial
skeleton – vertebral column, skull, ribs
 Appendicular
skeleton – arms and legs
7
Vertebrate Circulation

Closed circulatory system

Heart located ventral to the vertebral column
 Can

have 2, 3, or 4 chambers
Blood vessels
 Arteries
 Veins
– carry blood away from the heart
– carry blood to the heart
 Capillaries

– tiny blood vessels; connect veins and arteries
Blood is red because of red pigment (hemoglobin)
8
Vertebrate Circulation
 Purpose
of blood
Transport
nutrients and O2 to cells
Transport
wastes and CO2 to other organs to be
removed from the body
Transport
 Kidneys
hormones to target organs
filter the blood to remove wastes produced
by the cells
9
Vertebrate Nutrition

Herbivorous – eats plants
 Cows,

Carnivorous – eats other animals
 Lions,

horses, squirrels, deer, giraffe, elephant…
polar bears, wolves, crocodiles…
Omnivorous – eat both plants and animals
 Bears,
pigs, badgers, most birds
10
Vertebrate Nutrition

Digestive system (alimentary canal)
 Mouth
 Salivary
glands
 Esophagus
 Stomach
 Small
intestine
 Liver,
 Large
gall bladder, pancreas
intestine
11
Vertebrate Reproduction

Internal Fertilization

External Fertilization

Methods of development
 Oviparous:
offspring hatch from eggs outside the body
 Viviparous:
offspring are born alive (develop inside mother)
 Ovoviviparous:
offspring are born alive without direct connection
to mother for nutrients
12
Vertebrate Nervous System

2 divisions of the nervous system
 Central
 Brain
nervous system (CNS)
and spinal cord
 Peripheral
 Cranial
nervous system (PNS)
nerves, spinal nerves, and sensory organs

PNS transmits stimulus to CNS

CNS interprets stimulus and sends response back to body
13
Vertebrate Nervous System

5 major lobes of the vertebrate brain

Olfactory Lobes – receive impulse from smell receptors

Cerebrum – controls voluntary muscle activity

Optic Lobes – receive impulse from eyes

Medulla Oblongata – transports impulses to and from the
spinal cord, and some reflexes

Cerebellum – coordinates muscle activity and some
involuntary activities
14
Vertebrate Behavior

Behavior
 The

way an animal responds to its environment
Inborn behavior
 Behavior
 Does
an organism has from birth
not learn it
 Reflex
 Eye
behavior – automatic, involuntary response to stimulus
blink, pulling away from pain, knee-jerk
 Instinct
Behavior – elaborate behavior in response to stimuli
15
Vertebrate Behavior

Conditioned Behavior
 Response
learned by experience

Seen in many areas, not just human taught behaviors

Ex. training a dog to do tricks, skunk spraying another animal

Intelligence
 the
ability to manipulate the environment with tools, find a
solution to a problem, or communicate with symbols

Many animals are capable of some intelligent behavior
16
Class Osteichthyes



Bony fish
Skull and vertebral column
made of bone
Fins
 Anterior
dorsal fin
 Posterior dorsal fin
 Pectoral fins
 Pelvic fins
 Anal fin
 Caudal fin
17
Class Osteichthyes

Body is covered with scales
 Scales

grow in size with fish
Glands beneath the scales
secrete a mucus
 Protects

and lubricates
Chromatophores are cells
that produce pigment
 Some
fish can change color by
rearranging the pigment
18
Class Osteichthyes

Mouth

Operculum

Nares

Lateral line
19
Internal Anatomy

Nervous System
 Olfactory
bulb
 Brain
 Spinal

cord
Circulatory System
 Heart
 Bulbus
arteriosus
 Afferent brachial artery
 Efferent brachial artery
20
Internal Anatomy

Respiratory System
 Gills
 Gill

rakers
Reproductive
 Gonad
 Urogenital
opening

Female spawns, male covers
eggs with milt
21
Internal Anatomy

Digestive System
 Esophagus
 Stomach
 Pyloric
ceca
 Intestine
 Anus
 Liver
22
Class Agnatha

Jawless fish

Lack scales, eel-like shape,
unpaired fins, skeleton of cartilage,
and jawless

Noted for its circular mouth with
rows of teeth

Ex. sea lamprey, hagfish
 Lampreys
 Hagfish
are parasitic
are bottom feeders
23
Class Chondrichthyes

Cartilaginous fish

Skeleton composed of cartilage (main characteristic)

Have ventral jaw and paired fins

Rays and skates
 Feed
on bottom dwelling animals
 Some
rays have sharp, venom filled
spines in the tail
24
Class Chondrichthyes

Sharks
 Identified
 Razor
by their torpedo shape
sharp, triangular teeth anchored into the skin (carnivorous)
 Internal
structure is similar to that of bony fish except they don’t
have a swim bladder
 Just
a large liver that acts similarily

They do NOT have to constantly swim to stay alive

Usually transported upside down when caught for research
25
Class Amphibia

Name means “double life”

Go through metamorphosis
 Egg,
2
chambered heart
 Gills
 Lose

larva, adult
3 chambered heart
lungs
tail (resorbed by body)
Webbing on feet of adults who spend much time in water
26
Class Amphibia

Skin
 Smooth,
scaleless, moist
 Moistened
 Rich
by secretions from glands in the skin
blood supply
 Allows
 Some
gas exchange through the skin (respiration)
secrete toxins onto their skin (protection)
 Chromatophores
color the skin
27
Class Amphibia

Respiration
 Gills
– during larval stage
 Lungs
– during adult stage
 Mouth
 Skin
and throat
– helpful during estivation
28
Class Amphibia

Circulatory System
 Amphibians
2

have a 3 chambered heart
atria, 1 ventricle
 Have
additional loop in the system
 Blood
mixes in ventricle
Reproduction
 Lay
soft eggs in aquatic environment
 Male
covers eggs with milt to fertilize (external) them
29
30
31
Frog

Circulatory System
 Heart
has 3 chambers
 Posterior
 Anterior
 Sinus
vena cava
vena cava
venosus
 Pulmonary
 Conus
arteries
arteriosus
 Pulmonary
veins
32
Frog

Nervous System
 Central
nervous system
 Brain
and spinal cord (encased in skull and vertebrae)
 Brain
has 5 lobes
 Peripheral
 Transmit
nervous system
impulses to and from CNS
33
Class Reptilia

Differences from amphibians
 Have
 Lay

lungs from birth
eggs encased in shells
 Have
claws on their toes (if they have limbs)
 Some
have 4 chambered heart
Similarities with amphibians
 Most
have 3 chambered heart
34
Class Reptilia

Skin
 Cool,
dry, leathery skin
 Scales
 Thick
made of keratin
to prevent water loss and heat loss

Reptile must molt periodically because scales do not grow

Ectothermic
35
Class Reptilia

Respiration
 Breathe
with lungs
 Contain
small air sacs called alveoli to
increase surface area for gas exchange

Circulation
3
chambered heart
 Partially
divided by septum
36
Class Reptilia

Nervous system
 Have
lobes
fairly large eyes and large optic
 Cerebrum
 Snakes
organ
is very large
and lizards contain Jacobson’s
 Sense
chemicals in the air captured by
tongue
37
Class Reptilia

4 categories of reptiles
 Snakes
and lizards
 Turtles
 Alligators
 Tuataras
and Crocodiles
38
Snakes

Movement
 Serpentine
 Moving
in an S-shape using rocks and twigs for traction
 Concertina
 Snake
draws itself into S-shape, then extends itself to move forward
 Rectilinear
 Scales
on belly grip the ground to push the snake forward
 Sidewinding
 Snake
moves sideways, usually through slippery places
39
Class Reptilia
Feeding of snakes
 Snakes eyes are not very sensitive, and they cannot hear

 Use

other sensory organs (Jacobson’s organ, heat sensors
Snakes kill prey by:
 Swallowing
prey alive
 Constriction
 Poison
 Neurotoxin:
poison that attacks the nervous system
 Hemotoxin: poison that attacks the blood
40
Class Reptilia

Turtles
 Reptiles
that have a shell
 Shell
consists of dorsal carapace and
ventral plastron

Sea turtles: turtles that live in the
ocean

Tortoises: turtles that live only on land

Terrapins: turtles that live in
freshwater
41
Class Reptilia

Crocodiles and alligators

Crocodiles: narrow, pointed snow

Alligators: broad, thick snout

Carnivorous

Oviparous
42
Class Reptilia

Tuatara
 Represented
by only a few
species living in New Zealand

Looks like a lizard, but
classified differently because
of structural differences