A polypneustic tracheal system has how many spiracular openings?

A polypneustic tracheal system has how many spiracular openings?

• A. 6-7 spiracles.
• B. 8-10 spiracles.
• C. 11-12 spiracles.
• D. 13-14 spiracles.

Answer: (B)

Insects with a polypneustic tracheal system have many spiracular openings along the body that feed air into the intricate network of tracheae. The idea is that “polypneustic” means multiple breathing pores rather than just a couple. Because there are several segments that bear spiracles, the total number tends to fall in the mid-to-high range rather than being very small or extremely high. Eight to ten spiracular openings in total is a typical pattern for this system, which is why that option is the best choice.

Insects with a polypneustic tracheal system have many spiracular openings along the body that feed air into the intricate network of tracheae. The idea is that “polypneustic” means multiple breathing pores rather than just a couple. Because there are several segments that bear spiracles, the total number tends to fall in the mid-to-high range rather than being very small or extremely high. Eight to ten spiracular openings in total is a typical pattern for this system, which is why that option is the best choice.