CHORDATA

By: Caroline Chandler, Meredith Wehrle, and Meredith Dickey

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

3 Subphyla: -Urochordata -Cephalochordata

-Vertebrata

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

7 CLASSES OF

VERTEBRATA

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