What are the peculiar characters of Aschelminthes?
(i) The body of aschelminthes is circular in cross-section, hence named round worms. (ii) They may be free living, a quatic and terrestrial or parasitic in plants and animals. (iii) They have organ-system level of body organisation. (iv) They are bilaterally symmetrical, triploblastic andpseudocoelomate. (v) Alimentary canal is complete with well developed muscular pharynx. (vi) An excretory tube removes body waste from the body cavity through the excretory pore. (vii) Sexes are separate (dioecious), i.e., males and females are distinct. Often females are longer than males. (viii) Fertilisation is internal and development may be direct or indirect. (ix) Examples. Ascaris (Round worm), Wuchereria (Filaria worm), Ancylostoma (Hookworm).
