CHORDATA

1. CHORDATA By: Caroline Chandler, Meredith Wehrle, and Meredith Dickey

2. 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.

3. 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

4. Reproduction and life cycles • Sexual reproduction • Several urochordata species reproduce asexually • Life cycles vary

5. 3 Subphyla: -Urochordata -Cephalochordata -Vertebrata

6. 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

7. Cephalochordata • Body laterally compressed and transparent (fish like) • All four chordate characteristics persist throughout lifetime • Motile

8. Phylogenic Tree… Chordata Urochordata Vertebrata Cephalochordata Agnatha Chondrichthyes Osteichthyes Amphibian Reptilia Aves Mammalia

9. 7 classes of vertebrata

10. Agnatha • Most primitive vertebrates • Jawless fish with cartilaginous skeleton • Also characterized by lack of paired fins • Notochord persists throughout life • Most are parasitic Hagfish Lamprey

11. Chondricthyes • “Chondra”=cartilage; “icthyes”=fish • Cartilaginous skeleton with jaw • Notochord becomes vertebrae in adults • Most fertilization internal Manta rays Shark

12. Osteichthyes • “Oste”=bone; “ichthyes”=fish • Bony skeleton and jaw • Most fertilization is external • Notochord becomes spinal chord • Most have swim bladder Coelacanth lobe-finned fish Carp-ray finned fish

13. 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 Salamander Toad Frog

14. 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…

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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