Echinodermata:

Organization: Organ level

Symmetry: Radial

Coelom: present (coelomates)  

Segmentation: Absent

Arrangement of embryonic layers: Triploblastic

Digestive system: Water vascular system

Circulatory system: Present

Respiratory system: Present

Habitat: Aquatic

Sexuality: Dioecious (sexes are separate).

 Notochord: Absent

 Reproduction: Sexual (oviparous)

Fertilization: External (indirect)

Respiratory organ: Water vascular system

Excretory system: Absent

Distinctive features:

• They are commonly called Spiny bodies.
• These animals have an endoskeleton of calcareous ossicles (bones).
•  They have a specialized water vascular system which helps in locomotion, capture and transport of food and respiration