Question 7
Sharks belong to the class of Chondrichthyes (chondrichthyans), which is different from the Osteichthyes or bony fish as their skeleton is cartilaginous. Sharks do not have any protective organs covering over their gills (called an operculum).
Consequently, to breathe, sharks have to ______
A. constantly move to keep the water flowing
B. breathe oxygen from the air
C. swim below the water surface
D. always open their mouth
Consequently, to breathe, sharks have to ______
A. constantly move to keep the water flowing
B. breathe oxygen from the air
C. swim below the water surface
D. always open their mouth