What does the mantle do in a banana slug?

• A. It covers part of the body.
• B. It covers part of the body and houses the pneumostome.
• C. It functions as a protective shell.
• D. It produces venom.

Answer: (B)

In banana slugs, the mantle serves two main roles: it covers part of the body and houses the pneumostome, the breathing opening. The mantle region sits over the visceral mass, and because banana slugs lack an external shell, it doesn’t act as a protective shell. Instead, the mantle provides a surface that protects internal organs and includes the pneumostome, through which air enters the mantle cavity to reach the lung. This combination—covering part of the body and containing the breathing pore—best describes the mantle’s function. The other ideas aren’t accurate: there’s no external shell to protect with, and the slug does not produce venom.