1. Vertebrates Animals that have a backbone.
Only 5% of all organisms on Earth are vertebrates!
Unlike invertebrates which have exoskeletons, vertebrates have an endoskeleton.

2. Exoskeleton Vs. Endoskeleton
Invertebrate
Hard outer covering
Protects
Does not grow with animal
Must shed and form a new one: molting
Animal is unprotected for a time until the new exoskeleton grows
Heavy—animals are small compared to ones with an endoskeleton
Endoskeleton
Vertebrate
Internal support system
Protects and allows movement
Specialized to protect the internal organs
Grows with the animal
Not as heavy as an exoskeleton, allows for larger animals

3. Exceptions!! Turtles have an endoskeleton and an exoskeleton.
Jelly Fish don’t have either one, they can change shape at will.

4. And the Vertebrates Are….
Fish
Amphibians
Reptiles
Birds
Mammals
All of these species has a backbone but they all have different adaptations that fit their environment.

5. Fish Most vertebrates are fish Most diverse group
Adapted for life under the water
Gills remove oxygen from water and exchange it for carbon dioxide in the fish’s blood
Swim bladder allows the fish to adjust how high or low it floats
Lateral line is an organ in the sensory system that allow fish to sense objects and organisms that are nearby.
Sexual reproduction, lay eggs

6. Fish: 3 Groups
Jawless: lampreys and hagfish, most similar to the first fish that lived on Earth
Jawless fish do not have stomachs and cannot chew although they do have teeth
Cartilaginous: Sharks, rays and skates, skeletons are made of cartilage.
Bony: 96% of fish are in this category
Most have scales, jaws, teeth and several pairs of fins

7. Amphibians First group of animals to live on land Two pairs of leg
Lay eggs in water
Obtain oxygen through their smooth, moist skin and many also have lungs
Sensory organs are adapted for sensing on land
Sexual reproduction, lay eggs that do not have hard shells

8. Life Cycle of Amphibians
Eggs hatch in water
The larva are called tadpoles
Tadpoles have gills, eat algae and move by pushing with their tails
As the tadpole grows it develops lungs, legs and its tail shrinks
The gills stop functioning and it is ready to live on the land

9. Reptiles Evolved after amphibians
Survive in hotter and dryer environments
Two pairs of legs
Tough, dry skin covered by scales
Respiratory organs called lungs
Sensory organs are adapted for sensing on land
Sexual reproduction, lay eggs with hard shell on land

10. Ectotherms
Both Reptiles and Amphibians are Ectotherms: their body temperature changes with the environment.
Adaptations for staying at the correct body temperature include: living near water, being able to slow their body processes during winter, standing on two feet to reduce the surface area in contact with hot sand.

11. Birds Have feathers and a beak
Four limbs: a pair of scaly legs and a pair of wings
Sexually reproduce, eggs have hard shells
Endotherms: maintain a constant body temperature
Generates heat by consuming food
This adaptation allows for diverse range of habitat
Birds can shiver to stay warm
Fluff their feathers to cool off
Seek shelter from the hottest part of the day

12. Adaptations for Flight
Endoskeleton: some of the bones are fused without joints. This makes the bird lighter but not as flexible.
Wings and Feathers
Respiratory system: air sacs and lungs move air constantly through the bird’s body.
Hollow bones
No heavy jaw bone or teeth, they grind their food in an organ called the gizzard.
Highly developed sense of sight and hearing

13. Mammals Hair during some part of their lives
Specialized teeth for consuming particular types of food
Hair and body fat are adaptations for controlling body temperature
Produce milk to feed their young
Endotherms
Sexual reproduction with the baby developing inside the mother in almost all species

14. Speaking of Babies Fish lay eggs and leave
Amphibians also lay eggs and have nothing further to do with their offspring
Reptiles leave the eggs once they are laid usually. Alligators and Crocodiles will protect their nests until the eggs hatch.
Birds incubate their eggs and care for the young
Mammals care for their young, sometimes as long as 18 years or more!!

15. Questions
Describe how you would determine if an animal was a salamander or a lizard.
Imagine that you live in Mexico and you have a pen pal who lives in Iceland. Both of you want to know about animals in the other person’s country. Which of you will be more likely to have seen wild reptiles? Why?