Give the characteristic features of the following

Chondrichthyes

Their habitat is mainly marine and their body is streamlined. They have a cartilaginous endoskeleton.

Examples are scoliosis and Trygon

Osteichthyes

The habitat is both marines as well as freshwater and they have a streamlined body. The endoskeleton is bony.

Examples are Marine: Hippocampus (Sea horse), Freshwater: Labeo (Rohu), Aquarium: Betta (Fighting fish)

(b) Urochordata and cephalochordate

In urochordates, the notochord is present only in the larval tail but in cephalochordates, notochord extends from head to tail region and is persistent throughout the life.

• Examples – Urochordates: Ascidia, Salpa, Cephalochordates: Branchiostoma.