Phylum Chordata!

Class amphibia

Class amphibia!

The amphibians– First vertebrates to inhabit

land

Still live part of life in water– Metamorphosis

Aprx. 5,000 species!Characteristics– Moist skin for gas exchange– Ectothermic– Larval stage

• metamorphosis

Movement from water to landWhat does it take to move from water to land? What has to change?

Small adaptations through Evolution

Transition from water to land

Living on land brings different challenges– Example: movement.

Amphibians are tetrapods: – “four footed: two sets of paired appendages that

are modified as legs that can support the animal.

Lungs to avoid drying out.

Adaptations = land living

New adaptations for living on land– Lungs – Ears – Four limbs with feet

and digits

CHARACTERISTICS

Ectothermic– Regulate temperature

from outside sources. • Basking in the sun

• Water temperature

Vs. Endothermic

What would be the advantages of both?

Ectothermic: Advantages

Slow Metabolism– Eat less

Must self warm blood enough to be active

Not enough energy for continued hard work

CHARACTERISTICS

Respiration: Porous skin – Allow for gas exchange

(breathing)– Must live in moist

environments to avoid drying out

Sensitive to chemicals in the environment Salamanders do not have lungs and

must breath through skin

REPRODUCTIONInternal sexual reproductionLay 100s of eggs – Advantage of over population of offspring?

METAMORPHOSIS

Amphibian = double life

DIGESTION

Adults: carnivores– Use sticky tongue to

trap and suck in prey – Eat anything that is

small enough to swallow whole.

Does that make them active

predators or scavengers?

Larva: herbivores

SENSES

Great hearing and eye sight – Hearing is Important for

terrestrial living

Frogs can see color!

Other senses… – Chemical receptors on

skin– Taste buds on tongue– Nasal senses

ECOLOGICAL ROLE

Important prey for: – Racoons, opossums,

birds

Important predator of – Mice, rats, insects

CFUHow do amphibians regulate their body temperature? What is this process called? How do amphibians exchange gasses? What does the word “amphibian” mean?What does it mean to be a vertebrate?What does it mean to be a tetrapod? What are some adaptations necessary for living on land?