VERTEBRATE ANIMALS• VERTEBRATES ARE ANIMALS WITH

ENDOSKELETONS VERTEBRATE ANIMALS HAVE BACKBONES– MOST VERTEBRATES ARE FISH– FISH CAN BE CLASSIFIED INTO 3 GROUPS– MOST YOUNG FISH DEVELOP INSIDE AN EGG

• AMPHIBIANS AND REPTILES ARE ADAPTED FOR LIFE ON LAND

• BIRDS MEET THEIR NEEDS ON LAND, IN WATER, AND IN THE AIR

• MAMMALS LIVE IN MANY ENVIRONMENTS

Vertebrates have backbones• Fish, frogs, snakes, birds, dogs, humans are all

vertebrates (animals with backbones)• Only 5% of animals are vertebrates (rest are

invertebrates) they are the most studied.• Have muscles, digestive systems, respiratory

system, & nervous system with sensory organs.

• Have endoskeleton-internal support system that grows with the animal; allow for more flexibility & movement.

• Named for specialized bones-vertebrae (backbones). Supports muscles & surrounds spinal cord (connects brain to nerves).

Most Vertebrates are Fish• More than 20,000 species of fish, in nearly every

aquatic environment.• Get oxygen from water, & move to find food.• Muscles & fins push bodies through water & move

them quickly. Many have swim bladder to control depth at which they float.

• Have sensory organs for taste, odor & sound; most have a lateral line (senses vibrations of objects)

• Gills made of many folds of tissue filled with blood (takes in oxygen from water into blood, and water is forced out through gill slits)

3 Groups of Fish• JAWLESS, CARTILGINOUS &

BONY FISH• Jawless have tube shape bodies

(lampreys & hagfish); digestive system with no stomach, but teeth- bite other organisms to attach & suck out flesh & fluids

• Cartilaginous = sharks, rays & skates; no bone but cartilage skeletons

• Some sharks pose danger to humans but most don’t & feed on fish, crustaceans & mollusks. Whale sharks feed by filtering small organisms as they swim.

• Rays have flat bodies, & skim ocean floor to feed on small animals in sand. Has large wing like fins on its side.

Bony Fish• Most fish (tuna, flounder, goldfish, eel) are bony

(96%)• Have bony skeletons, and most fish are covered

with scales, have jaws, teeth & several pair of fins.• Tropical fish are bright & colorful (may give

camaflouge in their environment or help to attract a potential mate.

Most young fish develop in eggs• Most reproduce sexually, female makes eggs, male makes

sperm• Often they select mates (female may only release eggs into

water when a certain male is around to fertilize them); then parent fish usually leave eggs to hatch on own, but are some exceptions.

• Most fish eggs are surrounded by a soft egg case that lets water pass through(giving it oxygen too); the yolk gives the developing fish food- so these eggs don’t need care from adult fish

• Since many animals eat fish eggs, fish often lay & fertilize many, so a few will survive to maturity.