Chondrichithyes

Osteichthyes

They are mostly found to be marine with a heterocereal tail.

They are found to be bony fish with homocereal tail.

Their endoskeleton is made up of cartilagenous.

Their endoskeleton is made up of  bone

Their skin is consisted with placoud scale.

Their Skin is composed with mucosglands, ganoid, cycloid otctenoid scales.

They have five to seven pairs of gills without opercula.

They have four pairs of gills with opercula.

They do not have  lungs or air bladder

They have bladder