Download Intro to chordates

Chordates
An Introduction
Kingdom Animalia- All inverts & verts
1. Phylum Chordata: All have nerve cords.
3 subphyla :
A- Urochordata (tunicates aka sea
squirts). Only larvae have notochord
B-Cephalochordata (lancelets aka
amphioxus). Retain notochord
throughout adulthood, but “musclelike” for burrowing
C-Vertebrata- Notochord becomes
backbone. 7 Classes
Section 33-1
Concept Map
Chordates
have the following
key features
Notochord
which is
Dorsal hollow
nerve cord
Postanal
tail
Pharyngeal
gill slips/ pouches
The Generalized Structure of a Chordate:
Section 30-1
A flexible
supporting
structure
We even start out this way in the womb!
Notochord
Muscle segments
Tail
Hollow
nerve cord
Anus
Mouth
Pharyngeal pouches
Chordates
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Phylum Chordata
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Phylum Chordata
• Notochord
• Gill slits or
pharyngeal
pouches
• Dorsal hollow
nerve cord
• Postanal tail
• Segmented
muscles
• Deuterostome
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Evolutionary Adaptations of Chordates
• From filter feeding
ancestors to active
predators
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Mobility
Oxygen capture
Digestion
Circulation
Nervous system
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Skeletal Changes
• Skeleton becomes
stronger to work with
bigger muscles
• Allows more rapid
movement
12
Oxygen Capture
• Gill slit and muscular
pharynx will move more
water over gills
– More oxygen is extracted
from water
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Circulation
• Stronger heart to
circulate blood faster
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Digestion
• Digest more food
– Muscularized gut
– Digestive glands
• Liver
• Pancreas
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Nervous System
• More complex for better
– Motor control of body to
capture food
– Sensory detection of the
animals environment
– Integration centers
(brain)
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Brain With Three Parts
Hindbrain
Midbrain
Forebrain
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Section 33-1
Nonvertebrate chordates
Jawless fishes
Cartilaginous fishes
Bony fishes
Amphibians
Reptiles
Birds
Mammals
Figure 33–2 A Cladogram of
Chordates
Chordate Cladogram
Mammals
Birds
Amphibians
Fishes
Nonvertebrate
chordates
Invertebrate ancestor
Reptiles
Figure 33–4 Diversity of Chordates
Section 33-1
Nonvertebrate chordates
(4%)
Mammals
(8%)
Birds
(18%)
Reptiles
(14%)
Amphibians
(9%)
Fishes
(47%)
Chordate Subphyla
Phylum.
Chordata
Urochordata
Subphylum. Cephalochordata
Subphylum. Vertebrata
Subphylum.
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Sea Squirts
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Subphylum Urochordata
• Sea squirts
• Gill slits (pharyngeal
slits)
• Notochord
– Only in larva
• Adult has tunic- made
of cellulose, sessile
• http://finstofeet.wordpre
ss.com/2010/03/14/1-2behold-the-tunicates/
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Subphylum Cephalochordata
• Amphioxus
• Notochord length of
body
• Dorsal hollow nerve
cord
• Gill slits
• Segmented muscles
• Maintain all chordate
characteristics as adult
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Amphioxus
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Amphioxus
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Subphylum Vertebrata:
All Vertebrates have:
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Closed circulatory system
Bilateral symmetry
True coelom
3 germ layers
Endoskeleton- backbone
Sexual reproduction- internal or external
Homeostasis
• Endothermic (warm-blooded)- internal temp.
regulation that must be maintained
Ex. Birds & Mammals
• Ectothermic (cold-blooded)- external temp.
regulation/ regulated by environment
Ex. Nonvertebrate chordates, Fish, Amphibians,
Reptiles
Temperature Control in
Chordates
Body Temperature (°C)
Section 33-2
Environmental Temperature (°C)
98.6 F- avg human temp
How vertebrates maintain their temperature
Animal Group
Endo/ectotherm
Behavior/structure
Fish
Ectotherm
Swim bladder:
Cold/move up
Hot/move down
Amphibian
Ectotherm
Cool/go in sun
Hot/go to water
Reptile
Ectotherm
Cool/bask
Hot/go to water
Birds
Endotherm
Cool/fluff feather
Hot/raise wings
Mammals
Endotherm
Sweat, pant,
shiver
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Agnatha
“Jawless” Fish (most primitive):
Traits:
-Sucker like mouth(no jaws)
-No fins or paired appendages
-Cartilage skeleton w/ notochord
Ex: lamprey & hagfish
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Chondrichthyes-Cartilage Fish
Traits:
Cartilage skeleton; 2 chambered heart
Lateral line system –detect vibrations
(movement & sense)
Paired appendages- pectoral and pelvic
girdles
Poor eyesight, great olfactory
Carnivorous or scavenger, no swim bladder
Ex: sharks, skates, rays
Kingdom Animalia
Phylum Chordata
Class Osteichthyes-
Bony Fish
Traits:
Bony skeleton; 2 chambered heart
Lateral line system/movement & sense
Swim bladder-control depth
(buoyancy)
Have operculum over gills
Good smell and eyesight
Ex: perch, bass, flounder
Kingdom Animalia
Phylum Chordata
Class Amphibia
Traits:
1st land vertebrates
3 chambered heart
Breath with skin/lungs
Need water to breed
Aquatic larvae; terrestrial adult
No scales or claws
Ex: frogs, toads, & salamanders
Kingdom Animalia
Phylum Chordata
Class Reptilia
Traits:
Imperfect 4 chambered heart
Dry, scaly skin
Breathe with lungs
Lay amniotic eggs
Ex: snake, turtle, lizards
crocodile, dinosaurs
Kingdom Animalia
Phylum Chordata
Class Aves-birds
Traits:
Down feathers for insulation
Air sacs/hollow bones make bird lighter
Lungs to breathe
4 chambered heart
Beak & feet adapted for food/habitat
Internal fert.,Lay amniotic eggs
Kingdom Animalia
Phylum Chordata
Class Mammalia
1. Have fur/hair
2. mammary glands
3. Length of time in uterus - gestation period
4. Give birth to live young (except monotremes)
5. 4 chambered heart
6. Diaphragm
7. Specialized teeth
Placental Mammals:
*Develop inside
uterus
*Ex:
people(primates), cats, dogs
(carnivores)
Marsupials:
pouch
*Develop inside
*Ex: kangaroos,
opossums
Monotremes:
*Lay eggs
Ex: platypus,echidna
Other placental orders
• Chiroptera-bats; only mammals that can fly;
nocturnal
• Rodentia-gnawing mammals with long
incisor teeth. Ex: rats, squirrels,
porcupines, rabbits
• Insectivora-long snout. Ex: shrews, moles
• Cetacea-Whales, dolphins
Terms to know
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Imprinting
Migration
Hibernation
Estivation
Oviparous
Viviporous
Oviviviporous
Evolution
• Change over time
• Which Chordate class do you think has
more advantages/adaptations to survive
changing times?
• Which classes have disadvantages?
• Which Chordate classes can you see
evolutionary similarities in so far?