What is a characteristic of Echinoderms' basic anatomy?

Echinoderms exhibit a unique characteristic of pentaradial symmetry, which means their body plan is organized around a central axis and can be divided into five or more symmetrical parts. This symmetry is especially evident in their adult forms, such as starfish and sea urchins. Additionally, echinoderms possess tube feet, which are a part of their water vascular system. These tube feet play a crucial role in locomotion, feeding, and gas exchange, allowing these organisms to thrive in marine environments.

The combination of pentaradial symmetry and tube feet is fundamental to their lifestyle, enabling them to navigate their underwater habitats efficiently. This anatomical feature distinguishes them from other groups that may display bilateral symmetry or different mechanisms for movement and feeding. Such adaptations are key to their ecological success in a variety of marine ecosystems.