Tube feet

Definition

Tube feet are small, flexible, hollow appendages found in echinoderms, such as sea stars and sea urchins, that function in locomotion, feeding, and respiration. These structures are part of the water vascular system and operate through hydraulic pressure, allowing echinoderms to move and manipulate objects in their environment.

5 Must Know Facts For Your Next Test

1. Tube feet are powered by hydraulic pressure created by the water vascular system, enabling them to extend and contract.
2. Echinoderms can use tube feet for locomotion by alternating the contraction of their tube feet, allowing them to move across surfaces.
3. In addition to movement, tube feet play a role in feeding by helping to grasp prey or manipulate food particles.
4. The adhesive ability of tube feet allows echinoderms to cling to surfaces, which provides stability in their often turbulent marine environments.
5. Some species of echinoderms can regenerate lost tube feet, showcasing their remarkable ability to recover from injury.

Review Questions

• How do tube feet contribute to the locomotion and feeding mechanisms of echinoderms?
  • Tube feet are essential for both locomotion and feeding in echinoderms. They allow these organisms to move by extending and contracting through hydraulic pressure from the water vascular system. During feeding, tube feet help grasp and manipulate prey, making it easier for echinoderms to consume food. This multifunctionality showcases how tube feet are integral to the survival strategies of these marine animals.
• Discuss the role of the water vascular system in the functioning of tube feet within echinoderms.
  • The water vascular system is crucial for the operation of tube feet in echinoderms. It consists of a series of canals filled with seawater that provide hydraulic pressure necessary for extending and retracting tube feet. The madreporite acts as an entry point for water into this system, allowing the organism to regulate pressure effectively. This unique adaptation not only facilitates movement but also supports other functions such as feeding and respiration.
• Evaluate the evolutionary significance of tube feet in echinoderms and their impact on ecological interactions.
  • Tube feet represent an important evolutionary adaptation in echinoderms that enhances their mobility and feeding strategies. By enabling precise movements and interactions with their environment, tube feet have allowed these organisms to exploit various ecological niches. Their ability to adhere to surfaces also provides advantages against predators and enables efficient foraging. The presence of tube feet has ultimately shaped the ecological roles echinoderms play in marine ecosystems, influencing both their survival and the dynamics of their habitats.

Related terms

water vascular system:

A unique network of fluid-filled canals in echinoderms that helps in movement, feeding, and gas exchange.

madreporite:

A porous, plate-like structure on the surface of echinoderms that serves as an entrance for water into the water vascular system.

ambulacral groove: A channel located on the oral side of echinoderms that houses the tube feet and is crucial for locomotion and feeding.