Revised 10/18/01
1. amphids not elaborate, oval, stirrup or pouch-like.
2. no body annuli.
3. cephalic sensory organs and somatic setae present or absent.
4. cylindrical esophagus, sometimes larger posteriorly.
5. five or more esophageal glands.
Two groups:
Marenoplica: a) marine inhabitants.
b) single excretory cell.
c) setae on head behind lip region.
d) male with elaborate supplements.
e) esophageal glands open anterior to nerve ring, three open into stoma.
Orders: 1. Enoplida - marine and brackish water, feed on diatoms, algae etc.
Terrenoplica: a) soil and rarely freshwater inhabitants.
b) excretory cell not seen, have hypodermal glands except in Trichodoridae.
c) no head setae.
d) male with delicate supplements.
e) esophageal glands open posterior to nerve ring,opening difficult to see.
Orders: 2. Isolaimida - long and slender, soil inhabitants.
3. Mononchida - strong, cuticularized stoma, predaceous and
cannibalistic. Soil and freshwater, no marine.
4. Dorylaimida - movable mural tooth or hollow spear. All
soil or freshwater inhabitants, no marine.
Longidoridae (plant parasites and vectors of plant viruses).
5. Stichosomida - multiple glandular esophagus - stichosome-
vertebrate parasites, e.g., Trichinella (trichinosis)
Trichuris (whip worm), invertebrate parasites, e.g., Mermis, Romanomermis.
6. Triplonchida - complex spear, esophagus gradually expanding from anterior
to posterior.
Trichodoridae (plant parasites and vectors of plant viruses).