Papulae

Definition

Papulae are small, finger-like projections on the surface of sea stars (Asteroidea) which function in respiration and waste removal. They are part of the echinoderm's coelom and extend through the body wall.

5 Must Know Facts For Your Next Test

1. Papulae are also known as dermal branchiae or skin gills.
2. They play a crucial role in gas exchange by increasing the surface area for oxygen absorption.
3. Papulae work in conjunction with tube feet to facilitate respiration in sea stars.
4. These structures contain thin walls that allow for efficient diffusion of gases directly with seawater.
5. Papulae can be retracted to protect them from predators or harsh environmental conditions.

Related terms

Tube Feet: Small, flexible, hollow appendages used for locomotion and feeding in echinoderms.

Madreporite: A sieve-like structure on the surface of echinoderms that acts as an entry point for water into the water vascular system.

Pedicellariae: Small pincer-like structures on echinoderms used to clean the body surface and capture prey.