Classification of Phylum Nematoda according to Ruppert & Barnes(1994)

Phylum :- Nematoda

Characters :- 

(i) They have perfectly cylindrical body adapted for living in minutes place.

(ii) Body cavity is pseudocoel, Cuticle thick & tough.

(iii) Circular muscle is absent, longitudinal muscles in 4 groups.

(iv) Anterior end bear sense organ amphid & posterior phasmid present.

Class :- Aphasmida

Characters :-

(i) Anterior end of body bear chemo receptor amphids, phasmid absent posteriorly.

(ii) Most are free living animal.

(iii) Excretory system relatively simple types.

(iv) Presence of cephalic setae & papillae.

Examples :- Trichurus; Trichenella;

Fig :- Trichenella

Fig :- Trichurus

Class :- Phasmida

Characters :-

(i) Possess anteriorly Amphids & posteriorly Phasmid.

(ii) Most are parasitic.

(iii) In the caudal region there is the presence of a pair of Phasmid.

 Examples :- Ascaris; Wuchereria; Ancylostoma;

Fig :- Ascaris

Fig :- Wuchereria bancrofti

Fig :- Ancylostoma