The tubular worms (Nemathelminthes or Aschelminthes), also known as round worms or hollow worms , are cylindrical, non-symmetrical worms with a length of a few millimeters to one meter. Tube worms form a group of primordial mouths (protostomia), which were previously regarded as taxons due to some similarities in their body structure . All tubular worms have a strongly developed foregut , which forms a muscular pharynx with cuticular stiffeners . Since the body cavity is not lined with an epithelium , it is usually interpreted as a primary body cavity (blastocoel). In addition, syncytia and multiple cell constancy (eutelia) often occur.
The exact extent of the tube worms has always been controversial, the following taxa were usually assigned to them:
- Scratchworms (Acanthocephala)
- Belly parsley (Gastrotricha)
- Hookweed (Kinorhyncha)
- Corset animal (Loricifera)
- Roundworms (Nematoda), for example the intestinal parasites roundworm , whipworm , pinworm , hookworm and dwarf threadworm
- String worms (Nematomorpha)
- Priapulida (Priapulida)
- Rotifers (Rotatoria)
- Volker Storch, Ulrich Welsch: Short textbook of zoology . 7th edition. Gustav Fischer, Stuttgart, Jena, New York 1994, ISBN 3-437-20507-2 , pp. 426-433 .
- Hans Adolf Kühn: intestinal parasites. In: Ludwig Heilmeyer (ed.): Textbook of internal medicine. Springer-Verlag, Berlin / Göttingen / Heidelberg 1955; 2nd edition ibid. 1961, pp. 834-841, here: pp. 837-840: Rundworms (Nemathelminthes).