How does slug mucus benefit the organism beyond locomotion?

• A. It stores nutrients.
• B. It helps prevent desiccation, supports moisture retention, and can deter some predators.
• C. It assists in photosynthesis.
• D. It hardens to form a shell.

Answer: (B)

Slug mucus serves as more than just a trail for moving. It forms a hydrated protective layer on the body that helps prevent water loss, keeping the slug from drying out in dry or hot environments and aiding moisture management during respiration and metabolism. This slippery coating can also deter predators, either by being sticky or by containing compounds that taste bad or irritate potential attackers, making it harder for them to bite or swallow the slug. These protective, moisture-retaining roles show why mucus is beneficial beyond simply helping the slug glide.

Nutrient storage, photosynthesis, or forming a shell aren’t functions of slug mucus. Slugs don’t photosynthesize, and they don’t develop shells like snails, nor does mucus primarily store nutrients.