Give the important distinguishing features of Arthropoda.
- These animals are bilaterally symmetrical and segmented.
- Body is covered with chitinous exoskeleton.
- One or two pairs of jointed legs are present.
- The body cavity is blood-filled and is called haemocoel.
- Body bears jointed appendages, and is divided into head, thorax and abdomen.
- Circulatory system is open, i.e., blood doesn’t flow in blood vessels.
Examples: Palaemon, cockroach and butterfly.