Chordate characteristics

1. ex. Humans, cats, horses, fish, frogs…
only about 5% of known species
Phylum Chordata

2. Characteristics of Phylum Chordata:
• Have a notochord = a stiff
rod of cartilage running down
the back of the animal.
– Later the notochord is
replaced by the backbone.
• Hollow dorsal nerve tube
• Gill slits (pharyngeal slits)
• Tail that extends past the
anus.

3. Post-anal tail

4. Phylum Chordata
Subphylum Hemichordata
Subphylum Urochordata
Subphylum Cephalochordata
Subphylum Vertebrata
Class Agnatha
Class Chondrichthyes
Class Osteichthyes
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia Order Placentals
Order Monotremes
Order Marsupials

5. Subphylum Hemichordata
The “Half Chordates”
• All are marine worm-like
animals
• Adults are benthic – live on the
sea floor
• Smallest species are only a
few mm long and the largest,
Balanoglossus gigas, can
reach lengths of 1.5m
• Tripartite (3 section) body plan
– protostome
– collar
– trunk

6. Subphylum Urochordata: ex) Tunicates
• “Sea Squirts”
• Spend most of their
lives attached to
docks, rocks or the
underside of boats
• Firm flexible body
covering called a
tunic composed of a
substance that is
similar to cellulose

8. Subphylum Cephalochordata: ex) Amphioxus

9. AMPHIOXUS or LANCELETAMPHIOXUS or LANCELET
LARVAELARVAE
ADULTADULT

10. Amphioxus
• From Greek for “both [ends] pointed”, aka lancelets
• Small, eel-like animals that spend much their time buried
in the sand
• Have over 100 pharyngeal slits or gill slits which are
used to strain food particles out of the water
• Are eaten by humans or domestic animals and are
commercially harvested for food in some parts of Asia

12. Subphylum Vertebrata Characteristics:
• Bilateral symmetry
• Coelom
• Have vertebrae = hollow, cartilaginous or
bony structures that surrounds & protects
the dorsal nerve cord
• Endoskeleton
• Large brain protected by a skull
• Complex heart, closed circulatory system
• 1 or 2 pairs of appendages
• Gills or lungs for breathing
• Special outer covering = “skin” (fur,
scales, fat, hair….)

13. Ecological roles of vertebrates:
• Food source
• Control animal and plant
populations
• Pollinators (birds, bats)
• Seed dispersal
• Aerate soil (moles,
squirrels)
• Create ponds - beavers

14. There are 7 classes of vertebrates:
• Class Agnatha
• Class Chondrichthyes
• Class Osteichthyes
• Class Amphibia
• Class Reptilia
• Class Aves
• Class Mammalia
**DO NOT COPY**

15. The Shape of Life
• Bones, Brains and Brawn:
http://www.dailymotion.com/video/x1ft0rl_
pbs-the-shape-of-life-8-of-8-bones-brawn-
and-brains_tv