Describe the characteristic features of the largest phylum of kingdom Animalia.

(i) Arthropoda have organ system level of organization.

(ii) They are bilaterally symmetrical, triploblastic , coelomated and segmented.

(iii) Body is covered by chitinous exoskeleton

(iv) Body consist of head, thorax and abdomen.

(v) They have joint appendages.

(vi) Open circulatory system

(vii) Respiration by gills / book lungs etc.

(viii) Excretion through malpighian tubules.