Which of the following is one of the major phyla of invertebrate animals?

The correct answer is Echinodermata.

Key Points

• These animals have an Endoskeleton of calcareous ossicles and, hence, the name Echinodermata.
  • The adult echinoderms are radially symmetrical but larvae are bilaterally symmetrical.
  • The digestive system is complete with a mouth on the lower (ventral) side and anus on the upper (dorsal) side.
  • The most distinctive feature of echinoderms is the presence of water vascular system which helps in
    locomotion, capture and transport of food and respiration.

Additional Information

•  Invertebrates have no backbone, while vertebrates have a well-developed internal skeleton of cartilage and bone and a highly developed brain that is enclosed by a skull.
• Vertebrates are divided into two groups: 
  • Animals without jaws and Animals with jaws.
  • While most Vertebrates can move and are Heterotrophic, some invertebrates may be able to make their own food.