Cold-blooded Vertebrates Notes

Characteristics of Vertebrates

1. Can live on land, in water, or in air

2. Belong to the Phylum Chordata

3. Have a Notochord

a flexible rod-like structure on the dorsal side or back of an animal

4. Have a dorsal nerve chord

a bundle of nerves that become the spinal chord

5. Gill Slits - located in the throat, behind the mouth

6. Have an endoskeleton

bones inside the body for protection and muscle attachment

7 Classes of Vertebrates

1. Fish

2. Amphibian

3. Reptile

4. Bird

5. Mammal

*6. Tunicates- live in salt water attached to the sea floor

*7. Lancelets- live in salt water usually buried in the sand

Fish Notes

There are more than 30,000 species of Fish

Fish are cold blooded vertebrates that have 3 adaptations that allow them to live in water.

1. All fish have gills for breathing.

Gills take in oxygen as water passes over them and releases carbon dioxide back into the water.

2. Most fish have fins for moving, balancing, and steering

3. Most fish have scales for protection

Fish are grouped into three categories:

1. Jawless fish

2. Cartilaginous fish

3. Bony fish

List 2 examples of jawless fish.

1. Lamprey

2. Hagfish

Observe the jawless fish’s mouth (page 352)

What is cartilage?

Tough, flexible tissue that is softer than bone and provides protection

List 3 examples of cartilaginous fish.

1. Sharks

2. Skates

3. Rays

What are their endoskeletons made of?

Cartilage

Unless they are provoked, few sharks will attack humans.

About 95% of all fish are in the Class Osteichthyes or the "bony fish"

How do these fish stay afloat?

Swim Bladder

Name and describe 3 types of bony fish.

1. Lobe finned fish - once thought to be extinct

2. Ray-finned fish - most common fish

3. Lungfish - have lungs and gills - burrow in the mud

Why are bony fish important?

1

2

3

4

Perch Notes

Perch live in freshwater lakes of the U.S. and Canada

Perch can grow up to 15 inches long

Perch can swim up 10 miles per hour

Perch Organs and Functions

External:

1. Operculum - covers and protects the gills

2. Lateral Line - runs down both sides of the fish has nerves that sense vibrations and chemicals in water

3. Pectoral and Pelvic Fins - used for steering the fish

4. Dorsal and Anal Fins - keep the fish upright and moving in a straight line (balance)

5. Caudal Fin - used for fast movement

Internal

1. Gills - remove oxygen from water

2. Heart - have a 2 chambered heart (humans have a 4 chambered heart)

3. Liver - red in color, helps digest food

4. Gall Bladder - stores chemicals made by the liver

5. Air Bladder - allows bony fish to control their depth in the water

6. Intestine - digestion of food occurs here

7. Brain - controls all senses and actions of the fish. Smell is the most important sense a fish has.

Reproduction

External Fertilization

Cold-blooded

Metamorphosis

Moist, smooth skin - no scales

Webbed feet - no claws

Breathe through gills, lungs and skin

Eggs do not have shells

Lay eggs in water - external fertilization

legs instead of fins

stronger bones and muscles

lungs instead of gills

Evolved after fish due to increased competition in the water

Amphibians were the dominant animals on land for 100 million years

Frogs - moist and smooth skin, short and broad body

Toads - dry and bumpy skin, short and stocky legs

Salamanders - long slender bodies, moist smooth skin

Frog

Bulging Eyes

Eyelids offer protecting from dust and dehydration

Nictitating membrane = a third eyelid that allows frogs to open eyes under water

External Nostrils

2 on the top of head

Located behind each eye

Aid in balance

Important during mating season - hearing mating calls

Skin

Skin stays moist so respiration can take place thru skin

Granular glands - secrete bad tasting or poisonous substances for protection

Mouth

Vocal Sacs

Glottis

Tongue - attached to the front of its mouth - flips it out

Maxillary Teeth - many small teeth

Vomerine teeth - two large teeth

Begin Frog Lab – External Anatomy

Reptiles

1. Thick, dry, waterproof skin

2. 4 Legs and claws- Except for snakes

3. Eggs have leathery shells

Holes in the shell to let oxygen in

4. Lungs for breathing - balloon-like

5. 3 Chambered Heart

Alligators and Crocodiles have a 4 chambered Heart

Internal Fertilization

Some reptiles lay eggs, others give birth to live young

3 Orders of Reptiles

Turtles:

do not have teeth use their beaks

eat insects, worms, fish and plants

Crocodiles and Alligators

Found in tropical/subtropical areas

Most are nocturnal

Alligators are less aggressive

Differences between Crocodiles and Alligators

Crocs - long, skinny snout

Alligators - broad, short snout

Lizards and Snakes

Largest Order of Reptiles

Compare and Contrast Reptiles and Amphibians

Snakes

Snake Senses

* Cannot see or hear well

* Have an enhanced sense of

smell (using their tongue)

Swallow food Whole - Rodents

Harmless North American Snakes

Constrictors

Boas

Pythons

Anacondas

Venomous

Cobras

Vipers = rattlers, copperheads

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