SCHOOL STRENGTH(a note on introduction to amphibian. For secondary schools)

•  Amphibians are organism with the ability to inhabit both  terrestrial and aquatic habitat. We can say they are able to live on land and in water.

• They are vertebrates.

• Amphibians evolved from lobed- fin fish.

                                                                                           

• The Amphibians belong to the class Amphibia.
• They evolved certain mechanisms and structures that allowed them to live on land and also in water. Let us look at some of these innovations that allowed for their survival on both habitats.

   ü  The developed legs to support their weight on land and also allow for movement. They are the first vertebrates to walk on land. Is that not cool?

  ü  They developed lungs which allowed them to exchange gases on land. Wow! This is the most important adaptation since amphibians no more needs dissolved oxygen to respire.                                                                                                  


     ü Amphibians developed a better heart, a three  chambered heart (ventricle and two atria).  They can now  pump that oxygen and nutrient to cells on record time!   Hippeee!!!

ü  The young ones are known as tadpoles and resemble a fish. The tadpoles have two chambered heart just like a fish and gaseous exchange is through gills.

ü  Amphibians can do without water too, they lay their eggs on water to avoid drying out. Oh watch out! The eggs are not tasty because of the sticky unpalatable liquid covering the eggs.

ü  They exhibit external fertilization. Males shed their sperm on the eggs immediately they are released.

ü  Most Amphibians undergo metamorphosis (life cycle). First the egg is led then it hatches releasing the larvae(tadpole), finally the tadpole undergoes different stages of development to become an adult

   ü  Most amphibians can breathe through their skin. They are super! Super! Organisms        And unique to be able to do that. This type of respiration is known as cutaneous respiration            

·                                           Amphibians are classified into three orders;

1.       The Anura (meaning ‘WITHOUT A TAIL’): this includes the frog and toads. There are 22 families and 3680 species of amphibians in this order. Wow! Isn’t that much specie?

2.         The Urodela (meaning ‘VISIBLE TAIL’): the salamanders are found here. There are about 369 species of amphibians in 6 families found here.

3.        The Apoda (meaning ‘WITHOUT LEG’): The amphibians in this order are usually found in the tropics. They might just be nearer than you think if you are living in the tropics. There are 6 families and 168 species in this order.

                            Scientific Classification of the African Dwarf Frog

 

Kingdom:  Animalia

Phylum:    chordate

Class:        Amphibia   chordata   oof the tadpole undergoes different stages of development to become ann

Order:        Anura

Family:       pipidae

Genus:      Hymenochirus Species:     boettgeri ,    boulengeri