It seems that it is possible:
Nematodes are slender, worm-like animals, typically less than 2.5 millimetres (0.10 in) long. The smallest nematodes are microscopic, while free-living species can reach as much as 5 centimetres (2.0 in) and some parasitic species are larger still. The body is often ornamented with ridges, rings, warts, bristles or other distinctive structures.
The above was from Wikki. And the accompanying photos they were clear looking.
Now the question would be... good nematode or bad guy?
Talk to your plants.... If your plants talk to you... Run!