Download Urochordata

Chordata:
Urochordata and
Cephalochordata
Joycelin Luc
Michelle Chen
http://www.glaucus.org.uk/diazona0.JPG
http://research.myfwc.com/images/gallery/20060309_140447_23656.jpg
Intro to Chordata
 Have a notochord
 Have a dorsal nerve cord => develops into
central nervous system (brain and spinal
cord)
 Most have pharyngeal clefts and
pharyngeal slits
 Usually have a post-anal tail
Michelle Chen
Common Names
Urochordata
 Tunicate
 sea squirts
 sea pork
Cephalochordata
 Lancelets
 amphioxus
(means “both
ends pointed”)
http://www.ucmp.berkeley.edu/chordata/urochordata.html (left pic)
http://www.biologycorner.com/resources/Lancelet.JPG (right pic)
Joycelin Luc
Urochordata
http://www.mun.ca/biology/scarr/Ascidian_metamorphosis_2.gif
Michelle Chen
Cephalochordata
Michelle Chen
http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb7pg1_files/amphioxsis.jpg
Body Cavity and Body
symmetry
 Coelom present in both the Urochordata
and Cephalochordata subphlya
 bilaterian (bilaterally symmetrical)
 Body consists of myoepithelial and
Epithelial cells
Michelle Chen
Nervous System &
Sensory Features
 Present consisting of brain and
spinal cord
 in Urochordata, nervous system
disintegrates when it reaches adult
stage
http://www.mun.ca/biology/scarr/142007_Urochordata.jpg
Michelle Chen
Circulatory System
Urochordata
 Blood contains high
concentration of
vandium and lithium
 Open circulatory
system
 Ventral heart


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

Cephalochordata
Closed blood system
Main ventral and
paired dorsal aorta
No central heart, but
consists of branches
lacks hemoglobin
and is colorless
Has Atria cavity
Joycelin Luc
http://faculty.vassar.edu/mehaffey/academic/animalstructure/outlines/chordata.html
Digestive & Excretory
System




Urochordata
Cephalochordata
Draws food through
 Uses cilia pumping
siphon into atrium from
to move food
pharyngeal slits
particles from slit
Food filtered by mucous  Trap food in pharynx
net
Moves to esophagus
through cilia
Exits excurrent siphon
Michelle Chen
Locomotion/ Musculature
Urochordata
 Juvenile: tail
muscles; gravity and
light sensitive cells
 Adult: attach to a
substrate
 sessile
Cephalochordata
 Contraction of
muscles arranged in
a <<<< structure -> a
side to side
undulation to move
forward
 Somites
Michelle Chen
Skeletal Type
Urochordata
Cephalochordata
 Notochord (some  Develops dorsal,
have spicule when
hollow never cord
young)
 Post-anal tail
 adult: attach to
rock
Joycelin Luc
Reproduction
Urochordata
 Hermaphrodites
 Eggs kept inside until
hatch
 Sperm released into
H2O
Cephalochordata
 Gonochoristic: sex
separate
 Sperm and eggs
released into water
 Fertilization is
external
Joycelin Luc
Gas Exchange
 Uses cilia to regulate the gases
 Pharynx and pharyngeal slits regulate the
gas exchange (across external body
surface)
Michelle Chen
Other unique features
 Urochordata = very few natural predators
 Invasive species
 Form colonies
Joycelin Luc
Quiz
1. What are the four basic features that
separate Chordata from other phyla?
2. Name one difference between Urochordata
and Cephalochordata.
3. How do adult sea squirts move? What about
adult lancelets?
4. How are the reproductive methods for
Urochordata and Cephalochordata
different?
Joycelin Luc
THE END!!!