Classification of Amphibia

 

Classification of Amphibia

The Amphibians are divided into three orders. The classification of amphibia is given below:

Apoda (Gymnophiona or Caecilia)

• Apoda means “without legs”.These are limbless organisms with scales on their body.

• They are also known as “blind-worms” because their eyes are covered by skin or bone.

• The tentacles on their head are the chemosensory organs that help them to detect the underground prey. Eg., Caecilians

• They possess venom glands.

• They secrete mucus to reduce water loss.

Urodela (Caudata)

• These are the organisms with a tail.

• The body is elongated with four equally sized limbs.

• The skin is smooth with poison glands.

• Fertilization is internal.

• They feed on insects and worms. Eg., Salamanders

• They are found under leaf litter, in the soil, or in water.

• In the southern US, they reproduce primarily in winters.

• Very little differences between male and female.

• Spermatophores are utilized for internal fertilization.

• They possess hidden gills.

Anura (Salientia)

• There are around 3400 species of Anura in the world.

• They have four limbs. The front limbs are elongated and modified to jump.

• The head and trunk are fused together.

• The tail is present only in the larval stage and is lost in the adults.

• Fertilization is external and the eggs are laid in water. Eg., frogs and toads.