Skeleton is made entirely of cartilage in
(a) Sharks
(b) Tuna
(c) Rohu
(d) None of these
The skeleton of cartilaginous fish is made up of cartilage. They are also called as Osteichthyes
e.g., Sharks whereas Tuna and Rohu are bony fishes with a bony structure. They are also called as Chondrichthyes
The correct answer is a) Sharks