FACTS ABOUT PHYLUM CHORDATA
Bilateral symmetry Three germ layers- endoderm, ectoderm,
mesoderm Well developed coelom Triploblastic Specialized tissues compose unique organs Urochordata- sessile Cephalochordate and Vertebrates are motile-
body designed for movement with ease Type of movement depends on species-jump,
swim, walk, etc.
DEVELOPMENT Body development in the Phylum Chordata varies greatly Vertebrata:
-some embryo develop in egg
-others develop in mothers uterus and are born live
-many specialized structures and organs Urochordata:
-produce free swimming larvae with notochord, dorsal tubular nervous system, and gill slits
-larval stage ends when organism finds a rock suitable for life
-adults have neither a notochord or nervous system Cephalochordata:
-have dorsal nerve cord, notochord, and gill slits
-maintain throughout life
REPRODUCTION AND LIFE CYCLES
Sexual reproduction Several urochordata species reproduce
asexually Life cycles vary
UROCHORDATA
marine sessile feed by filtering food particles from seawater
taken in through one opening, or siphon, and squirted out the other
disperse themselves with free-swimming larvae
CEPHALOCHORDATA
Body laterally compressed and transparent (fish like)
All four chordate characteristics persist throughout lifetime
Motile
PHYLOGENIC TREE…
Chordata
Urochordata CephalochordataVertebrata
Agnatha
Chondrichthyes
Osteichthyes
Amphibian
Reptilia
Aves Mammalia
AGNATHA Most primitive vertebrates Jawless fish with cartilaginous skeleton Also characterized by lack of paired fins Notochord persists throughout life Most are parasitic
Lamprey
Hagfish
CHONDRICTHYES “Chondra”=cartilage; “icthyes”=fish Cartilaginous skeleton with jaw Notochord becomes vertebrae in adults Most fertilization internal
Shark
Manta rays
OSTEICHTHYES “Oste”=bone; “ichthyes”=fish Bony skeleton and jaw Most fertilization is external Notochord becomes spinal chord Most have swim bladder
Carp-ray finned fish
Coelacanthlobe-finned
fish
AMPHIBIANS First vertebrates to move to land Amphibian means “double life”- refers to
metamorphosis and the fact that larvae live in water and adults live on land
Evolved from lobe-finned fish
Frog
Toad
Salamander
DID YOU KNOW…
…one of the differences between toads and frogs is that toads lay their eggs in long, tube-like protective membranes, while frogs lay theirs in clusters?
Toads also have more dry, “warty” skin, while frogs have more smooth and slimy skin
Contrary to popular belief, toads do NOT give you warts…
REPTILIA Evolved from amphibians Adapted to live in hot, dry places Internal fertilization First class to have amniotic egg Carnivores, developed strong teeth and claws
Structure of the
amniotic egg
AVES Adapted for flight Thought to be evolved from dinosaurs Feathers and wings Hollow bones make birds lighter for flight Have a beak instead of a jaw Internal testes- external testes would cause
balance problems Amniotic egg
AVES ANCESTORS…
Birds are thought to have evolved from flying dinosaurs…
Until 1991, everyone thought birds evolved from the Archaeopteryx. Then…
…a paleontologist found fossils of a flying dinosaur believed to be even older. It was named Protoavis
Due to inconsistencies in information, the Archaeopteryx is still viewed as the ancestor of birds
MAMMALIA Evolved from reptiles Almost all give birth to live young Have fur/hair and subcutaneous (under-the-skin) fat
for insulation Well suited for cold climates 3 groups:
-Monotremes: lay eggs, most primitive
-Marsupials: give birth to young very early in development and complete development in mother’s pouch
-Placentals: complete development in uterus
AT SOME POINT, ALL CHORDATE HAVE…
Notochord- a longitudinal, flexible rod formed from the dorsal mesoderm and located between the gut and the nerve cord in all chordate embryos
Hollow dorsal nerve cord- dorsal to notochord, late become brain and spinal cord
Pharyngeal gill slits- used for feeding; slits lined with beating cilia pull in water and filter it for food
Postanal tail-an extension beyond the anus of the notochord or backbone and of the body-wall musculature, containing no internal organs
WORKS CITED Pictures:
“The Vertebrates” http://www.earthlife.net/inverts/images/others/vertebrates.jpg
Cephalochordata http://www.talkdesign.org/faqs/evimmune/ei_animal004.jpg
Urochordata http://www.faunanet.gov.au/wos/images/groups/g16.jpg
Hagfish http://grad.bio.uci.edu/ecoevo/aclark/hagfishpic.jpg
Lamprey http://people.cornellcollege.edu/b-hess/geo105/images/lamprey.jpg
Shark http://michaelscomments.files.wordpress.com/2007/10/shark.jpg
Manta rays http://www.aquarticles.com/images/China4b/p47a%20Manta%20rays.jpg
Carp http://pond.dnr.cornell.edu/nyfish/Cyprinidae/common_carp.jpg
Coelacanth http://www.cartage.org.lb/en/themes/Sciences/Zoology/Biologicaldiverstity/AnimalsIII/coelacanth.jpg
Toad http://www.glaucus.org.uk/toad9077-RH.jpg
Frog http://news.nationalgeographic.com/news/2007/09/images/070928-frog-picture_big.jpg
Salamander http://www.argo217.k12.il.us/departs/English/blettiere/451_salamander.jpg
Amniotic egg http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/ilt/T013908A.gif
Dinosaur http://www.tapirback.com/tapirgal/gifts/friends/dinosaurs/dinosaur-plastic-velociraptor-f668.jpg
Bird http://www.tapirback.com/tapirgal/gifts/friends/dinosaurs/dinosaur-plastic-velociraptor-f668.jpg
Platypus http://cache.eb.com/eb/image?id=94548&rendTypeId=4
Kangaroo with joey http://www.northrup.org/photos/crap/Animals/low/kangaroo-joey.jpg
Cat with kittens http://www.charitywebcam.co.uk/rspca/images/uploads/Julieandkittens.jpg
Frog life cycle http://dj003.k12.sd.us/images/frog%20dissection/frog_life_cycle.gif
Chicken egg http://www.dkimages.com/discover/previews/863/20492236.JPG
Lancelet faculty.clintoncc.suny.edu/.../deuterostomes.htm
Urochodate http://www.emc.maricopa.edu/faculty/farabee/BIOBK/a_urochordate.gif