Phylum Aschelrninthes (Nemalhelminthes)

Explanation

(i) The body of these animals is long thread-like or cylindrical. Hence, called as round worms.
(ii) They are either free living or endoparasites. Free living are either aquatic or terrestrial.
(iii) These animals are triploblastic and pseudocoelomate.
(iv) Body is unsegmented and covered with cuticle.
(v) These animals are unisexual, i.e. sexes are separate. e.g. Ascaris, (Intestinal worm), Filarial worm, LoaIon, (Eye worm)