Question

Explain in brief criteria for animal classification.

Answer 1

Criteria for animal classification are:

1. Symmetry: Animals are radially symmetrical, bilaterally symmetrical or asymmetrical.

2. Segmentation: Animals may or may not have segmented body.

3. Appendages: Animals may have organs or parts attached to the trunk or outer body wall.

4. Skeleton: Animals may have exoskeleton or endoskeleton.

5. Embryonic development:

6. Circulatory system: Animal may have open or closed circulatory system.

7. Body cavity: Animals may be coelomate, psuedocoelomate or acoelomate.

8. Habitat: Animals may be terrestrial or aquatic. Aquatic animals may live in either fresh water or sea water.

9. Germ layers: Animals may be diploblastic or triploblastic.