Give an account on phylum Arthropoda.

Explanation

(i) Anhropoda is the largest phylum.
(ii) The organism s have jointed legs.
(iii) The body is segmented into head, thorax and abdomen.
(iv) The exoskeleton is made up of chitin.
(v) The coelomic cavity is filled with haemolymph (blood).
(vi) They do not have defined blood vessels. This is called open circulatory system.
(vii) The insects shed the exoskeleton and this process is called moulting.
(viii) Small Arthropods absorb oxygen through the body and larger aquatic species breathe through book gills.
(ix) Land Arthropods breathe through a system of tiny body tubes called tracheae.
(x) Excretion occurs through malphigian tubules and through green glands in crabs and prawns.
(ix) Insects, spiders, crabs, shrimps, butterflies, millipeds, centipedes, and scorpions are some arthropods.