Phylum Chordata--Vertebrate chordates: fishes, amphibians, reptiles, birds, mammals--Invertebrate chordates: tunicates and lancelets

Characteristics (embryonic development)

Dorsal hollow nerve cordNotochord—firm flexible supporting rod located just below the nerve cordGill slits—paired opening along the pharynxPost anal tail…extends beyond the anus

EndothermicWarm blooded..temp is controlled by internal processes

EctothermicCold blooded..temp is regulated by external environment

Three Subphylums

1. Urochordata--tunicates (sea

squirts)--most adults are

sessile, squirt water when disturbed

2. Cephalochordata

LanceletsCan swim but prefer to stay buried in the sandFilter feeders

3. Vertebrata (humans)

Animals with backbonesDorsal hollow nerve cord becomes the spinal cord and brainNotochord is the backboneGill slits become other breathing organsTails are kept in most vertebrate animals

Six Classes

1. Agnatha--no jaw (jawless fish)--skeleton made of cartilage--snake-like body without

paired fins (not good swimmers)

Examples

Lampreys—attach to other fish using their round mouth and its rasping parts (parasites)Hagfish—scavengers, move slowing through cold water using tentacles to locate dead and dying fish

Hagfish

Have you ever gone fishing? Tell me about your experience.

ORPick your favorite fish and describe it. Why do you like it.

2. Chondrichthyes

Sharks, skates, raysGeneral characteristics

Skeleton mostly made of cartilageHave scales made of dentinExcellent sense of smellLateral line picks up vibrations

Sharks—torpedo shape bodyfertilization is internal and the eggs develop internallyYoung sharks are called pupsMust keep moving to keep water flowing through gillsOily liver helps buoyancy

Skates and Rays—basically benthic (bottom) lie and wait animalsHave a tail which can cause painPectoral fins are expanded and they look like they are gliding in the water

3. OsteichthyesCharacteristics

Bony skeleton—bony fishesSwim bladderScalesPaired finsOperculum flap covering gills2 chambered heartkidneys

Page 608…Read the life cycle section

Using complete sentences, explain the life cycle of a frog

Compare and contrast the animals in the class chondrichthyes to the animals in the class osteichthyes.

4. Amphibians

frogs, salamanders, toads, caeciliansSpend part of their life in the water and part living on land

Tadpole Frog

Frogs

Have a nictitating membrane over their eye…keeps eye moist in air and protects in the waterHear through a tympanic membrane (detect sound through air and water

Digestive System

Path of food Mouth, esophagus, stomach, small intestine, large intestine, cloaca

Undigested food along with products from the excretory system and reproductive system empty into the cloaca

Respiratory

Breathe using lungsDiffuse oxygen through skin (must stay moist)Tadpoles have gills for gas exchange

Circulation

Double loop circulationThree chambered heartDeoxygenated blood flows to the heart, then it is pumped to the lungs where it is oxygenated, then it flows back the heart to be pumped to the rest of the body

Metamorphosis

Frogs are the only amphibian to go through this process

EggTadpole…tail, gills, lives in waterFrog…no tail,lungs,has legs, lives on land

Page 608

A froggie eats bugs. Tell me the pathway that the bugs will travel as they go from the froggie’s mouth to its anus.

Look at the five pictures on page 804

List some adaptations that you see for these reptiles.Must have at least 5

5. Reptiles

EctothermicEgg-laying..soft, leathery shellsScaly dry skin..adaptable to life on landInternal fertilization

Breathe with lungsEndoskeleton3-chambered heart except crocodilians

Kidneys remove wastes and absorb most of the waterShed skin

Eggs are called Amniotic eggs b/c they have a fluid filled amnion sac which surrounds the embryo

6. Aves

FeathersContour feathers—have a stiff central barbDown feathers—short shafts, for insulationOil gland at base of feather..waterproof

Wing flowBones are hollow to reduce density

Fused collarbone and vertebra…furcula

4-chambered heart

Endothermic (warm blooded)High metabolism (eat a lot!)

Digestive system..crop (storage), gizzard (grinding…often contains stones)

Unique respiratory system

Anterior and posterior air sacs in addition to lungsAir flows in air sacs in only one direction (pg 810)

Excretion..no urinary bladder

Special glands around the eyes remove excess salts

7. Mammals

Mammary glands..produce milk to nurse youngFur or hairEndothermicWell developed brainsInternal fertilization…live birth

Breathe with lungsContain air sacsDiaphragm..muscle under lungs which helps breathing

Examples…•Monotremes: mammal that lays eggs (duck-billed platypus

•Marsupials: Kangaroo..give birth to small immature young that further develop inside mom’s pouch (Pg 829)

•Placental: young develops more fully before birthPlacenta..organ attached to mom and fetus

Mammalian Teeth

Page 823

Orders of Placental MammalsPage 830