Final answer:
Sharks do not breathe through their nostrils. Instead, they use gills to extract oxygen from the water.
Step-by-step explanation:
Sharks do not breathe through their nostrils/nares. Instead, they use a specialized respiratory organ called gills to extract oxygen from the water. Gills are located on the sides of the shark's head, and as water passes over the gills, oxygen is extracted and carbon dioxide is released. The gills are made up of filaments that contain many tiny blood vessels, allowing for efficient gas exchange.