Nematoda (Roundworms)
George Poinar, Oregon State University, Oregon, USA
Published online: September 2020
DOI: 10.1002/9780470015902.a0029191
Abstract
The Nematoda are a group of nonsegmented worm‐like invertebrates that occur worldwide in a wide range of habitats, including
fresh and saltwaters, soil, plants and animals. They are one of the most abundant group of invertebrates on the face of the
earth and rival the arthropods in biodiversity and species abundance. Their estimated numbers range from 1.5 billion in an
upper 20 mm in 1.6 hectares of marine beach sand to 380 million in a square meter of leaf litter. Evidence from fossils and
extant forms indicate that they evolved in the sea and came on land by probably moving up brackish estuaries into freshwater
habitats. While many of the plant parasites are considered pests and controlled with nematicides, other nematodes are important
in controlling agricultural and medically important insect pests, and still, others have been used as experimental model organisms
in genetics.
Key Concepts
- Nematodes are the most successful group of the Ecdysoma or pseudocoelomate bilateria.
- Nematodes are one of the most abundant groups of invertebrates.
- Some 22 000 nematode species have been described.
- Estimates for species diversity range from 100 000 to 10 million.
- Plant‐parasitic nematodes can be important agricultural pests.
- Many nematodes are parasites of invertebrates, humans and other vertebrates.
Keywords: nematodes; roundworms; plant parasites; metazoans; invertebrates
References
Anderson RC (2000) Nematode Parasites of Vertebrates, 2nd edn. CABI Publishing: Wallingford.
Chitwood BG and Chitwood MB (1974) Introduction to Nematology. University Park Press: Baltimore, MD.
De Ley P and Blaxter ML (2002) Systematic position and phylogeny. In: Lee DL (ed.) The Biology of Nematodes, pp 1–30. Taylor & Francis: London.
De Ley P and Blaxter ML (2004) A new system for Nematoda: combining morphological characters with molecular trees, and translating clades into ranks and taxa. In: Cook R and Hunt DJ (eds) Nematology Monographs and Perspectives, vol. 2, pp 633–653. Brill: Leiden.
Dropkin VH (1980) Introduction to Plant Nematology. Wiley: New York.
Eyualem‐Abebe, Andrássy I and Traunspurger W (eds) (2006) Freshwater Nematodes: Ecology and Taxonomy. CABI Publishing: Wallingford.
Megen HHB, Elsen SJJ, Holterman MHM, et al. (2009) A phylogenetic ress of nematodes based on about 1200 full‐length small subunit ribosomal DNA sequences. Nematology 11: 927–950. ISSN: 1388‐5545.
Poinar GO Jr (1975) Entomogenous Nematodes. A Manual and Host List of Insect–Nematode Associations. EJ Brill: Leiden.
Poinar GO Jr (1983) The Natural History of Nematodes. Prentice‐Hall: Englewood Cliffs, NJ: New York.
Poinar GO Jr Porter SD, Tang S and Hyman BC (2007) Allomermis solenopsi n. sp. (Nematoda: Mermithidae) parasitising the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) in Argentina. Systematic Parasitology 68: 115–128.
Poinar GO Jr (2011) The Evolutionary History of Nematodes. E J Brill: Leiden.
Poinar GO Jr (2015) Phylum Nematoda. In: Thorp J and Rogers DC (eds) Ecology and General Biology: Thorp and Covich's Freshwater Invertebrates, pp 273–302. Academic Press: New York.
Smythe AB, Holovachov B and Kocot KM (2019) Improved phylogenomic sampling of free‐living nematodes enhances resolution of higher‐level nematode phylogeny. BMC Evolutionary Biology 19: 121–135.
Further Reading
Andrássy I (2005) Free‐living nematodes of Hungary (Nematoda errantia). I. 518pp. Hungarian Natural History Museum and Systematic Zoology Research Group of the Hungarian Academy of Sciences: Budapest. ISBN: 9637093907; 9789635085743.
Grasse PP (1965) Traite de Zoologie, Tome IV, Nemathelminthes (Nematodes). Masson et Cie, Fasc. 2 and 3: Paris.
Levine ND (1968) Nematode Parasites of Domestic Animals and of Man. Burgess Publishing: Minneapolis, MN.
Thorne G (1961) Principles of Nematology. McGraw‐Hill: New York.
Yamaguti S (1961) Systema Helminthum, The Nematodes of Vertebrates, Parts 1 and 2, vol. III. Interscience Publishers, Inc.: New York.
Zuckerman BM, Mai WF and Rohde RA (eds) (1971) Plant Parasitic Nematodes, vol. 1 and 2. Academic Press: New York.
