An organism that has no body cavity (coelom)
You can get them from eating under cooked meat. You can get them from eating under cooked meat.
A Roundworm or Nematode has a "tube" like body within a tube, with a fluid- filled cavity in between the tubes. Most nematodes are parasites, such as ascarids, filarids, pinworms, hookworms, and...
sexually
pseudocoelomates