NEMATODA
Nematodes are slender worms, typically less than 2.5 mm (0.098 in) long. The
smallest nematodes are microscopic, while free-living species can reach as much
as 5 cm (2.0 in), and some parasitic species are larger still, reaching over a
meter in length.:271 The body is often ornamented with ridges, rings, bristles, or other distinctive
structures. The head of a nematode is relatively distinct. Whereas the rest of the body
is bilaterally symmetrical, the head is radially symmetrical, with sensory
bristles and, in many cases, solid 'head-shields' radiating outwards around the
mouth. The mouth has either three or six lips, which often bear a series of
teeth on their inner edges. An adhesive 'caudal gland' is often found at the tip
of the tail.
smallest nematodes are microscopic, while free-living species can reach as much
as 5 cm (2.0 in), and some parasitic species are larger still, reaching over a
meter in length.:271 The body is often ornamented with ridges, rings, bristles, or other distinctive
structures. The head of a nematode is relatively distinct. Whereas the rest of the body
is bilaterally symmetrical, the head is radially symmetrical, with sensory
bristles and, in many cases, solid 'head-shields' radiating outwards around the
mouth. The mouth has either three or six lips, which often bear a series of
teeth on their inner edges. An adhesive 'caudal gland' is often found at the tip
of the tail.