Question

Write down four general characters of phylum Echinodermata. Give two examples.

Answer 1

Phylum Echinodermata:

1. Echinoderms are marine animals and can be found in the depths of the ocean as well as in the intertidal zone.
2. In Greek, echinos means hedgehog (spiny mammal), and derma means skin.
3. Thus, the literal meaning of echinoderms is spiny-skinned organisms.
4. All animals belonging to Echinodermata are marine.
5. These are exclusively free-living marine animals.
6. They are triploblastic and have a coelomic cavity.
7. There are 2 symmetry present in echinoderms.
8. The adult echinoderms have radial symmetry but larvae have bilateral symmetry.
9. Simple animals may be star-like, spherical, or elongated.
10. Body lacks the head but has oral and aboral surfaces.
11. Oral surface of the body has five radial areas called ambulacra.
12. Body wall is covered with spiny hard calcareous (calcium carbonate) plates (ossicles) that form a rigid or flexible endoskeleton.
13. Examples are sea stars and sea urchins.