Vertebrates

vertebrates

contain a backbone or spinal column

Hagfish

eel-like WITHOUT jaws, paired fines, or bones; no vertebrae

Lamphrey

like a hagfish but with primitive vertebral column of cartilage; WITHOUT jaws

Cartilaginous fish

sharks, rays, skates, and ratfish

• skeleton made up of cartilage and unique scales on skin

Lobed-fin fish

lungfish and coelacanth

• mostly EXTINCT

• ancestors to amphibians, fins supported by main axis of bones

Bony fish (ray finned fish)

normal fish

• jaws, paired fins, and a skeleton of BONE

• lungs or swim bladder (helps fish stay afloat), gills in most

• scales covered in mucus to reduce friction

Reproduction in fish

all have separate sexes (sperm in testes and eggs in ovaries), external fertilization & development, high mortality rate for eggs & young

Amphibians

frogs, salamanders, mudpuppies, newts, etc.

• moist, thin skin without scales

• feet are webbed

• gills, lungs, and skin for respiration (eggs lack multicellular membranes for respiration)

Amphibian life cycle

aquatic larvae, terrestrial adults

How do amphibians regulate their temperature?

Ectothermic

Ectothermic

temperature is dependent on enviornment

Amphibian blood circulation

3 chambered heart (2 atria and 1 ventricle), double-circulation system

• oxygen rich & poor blood mix

Amphibian reproduction

separate sexes & external fertilization & development

Metamorphosis in frogs

• eggs hatch and become tadpoles (herbivorous)

• legs and arms develop as tail is absorbed

• adults become carnivorous

Reptiles

snakes, crocodiles, alligators, turtles, lizards, and caymans

• terrestrial

• body covered with dry scales

• breathe through lungs with alveoli (little vessels)

How do reptiles regulate their temperature?

ECTOTHERMIC

Reptiles blood circulation

3.5 chambered heart (2 atria, 1.5 ventricles with a septum)

• blood does not mix

amniotic egg

allows for fetal development OUT of water

• big evolutionary moment

• contains many membranes & protective layers around embryo

Oviparity

female lays fertilizes eggs (reptiles, all birds, 3 types of mammals)

Oviviparity

fertilized eggs remain in body for a short time (pit vipers, some sharks)

Viviparity

no shell forms & young retained in body until mature; receives oxygen and nutrients via placenta

Birds

feathers, wings, hollow-boned skeleton, lungs

• oviviparity

How do birds regulate their temperature

ENDOTHERMIC

Endothermic

control their internal temperature

Birds blood circulation

4 chambered heart (2 ventricles, 2 atrium) with a septum that does not allow mixing of blood

• double pump

Mammals

hair, lungs, specialized teeth

How do mammals regulate their temperature?

ENDOTHERMIC

Mammals blood circulation

4 chambered heart

• double pump

Monotremes

duck-billed platypus, echidna

• oviparous

Marsupials

kangaroo, koala, opossum, tasmanian devil

• embryo develop in uterus and then leaves to go into marsupial to complete development

Placental Mammals

humans +more

• viviparous

• embryo receives nourishment through placenta

• young feed on mammary glands that produce milk

• internal fertilization & development