# Nematode

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Phylum of worms

Nematode Temporal range: Early Devonian – Recent[1] PreꞒ Ꞓ O S D C P T J K Pg N Possible Cambrian occurrence[2] Caenorhabditis elegans, a model species of roundworm Scientific classification Kingdom: Animalia Subkingdom: Eumetazoa Clade: ParaHoxozoa Clade: Bilateria Clade: Nephrozoa Clade: Protostomia Superphylum: Ecdysozoa Clade: Nematoida Phylum: Nematoda Diesing, 1861 Classes Chromadorea Enoplea (see text) Synonyms Nematodes Burmeister, 1837 Nematoidea sensu stricto Cobb, 1919 Nemates Cobb, 1919 Nemata Cobb, 1919 emend.

The **nematodes** ([/ˈnɛmətoʊdz/](https://en.wikipedia.org/wiki/Help:IPA/English) [/ˈniːm-/](https://en.wikipedia.org/wiki/Help:IPA/English) [*NEM-ə-tohdz*](https://en.wikipedia.org/wiki/Help:Pronunciation_respelling_key) or [*NEEM-*](https://en.wikipedia.org/wiki/Help:Pronunciation_respelling_key); [Ancient Greek](/source/Ancient_Greek_language): Νηματώδη; [Latin](/source/Latin_language): *Nematoda*), **roundworms** or **eelworms** constitute the [phylum](/source/Phylum) **Nematoda**. [Species](/source/Species) in the phylum inhabit a broad range of [environments](/source/Natural_environment). Most species are free-living, feeding on [microorganisms](/source/Microorganism), but many are [parasitic](/source/Parasitism). [Parasitic worms](/source/Parasitic_worms) (helminths) are the cause of [soil-transmitted helminthiases](/source/Soil-transmitted_helminthiasis).

They are classified along with [arthropods](/source/Arthropod), [tardigrades](/source/Tardigrade) and other [moulting](/source/Moulting) [animals](/source/Animalia) in the [clade](/source/Clade) [Ecdysozoa](/source/Ecdysozoa). Unlike the [flatworms](/source/Flatworm), nematodes have a tubular [digestive system](/source/Digestion), with openings at both ends. Like tardigrades, they have a reduced number of [Hox genes](/source/Hox_gene), but their sister phylum [Nematomorpha](/source/Nematomorpha) has kept the ancestral [protostome](/source/Protostome) Hox genotype, which shows that the reduction has occurred within the nematode phylum.[3]

Nematode [species](/source/Species) can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity suggested there are over 25,000.[4][5] Estimates of the total number of [extant](/source/Neontology#Extant_taxa_versus_extinct_taxa) species are subject to even greater variation. A widely referenced 1993 article estimated there might be over a million species of nematode.[6] A subsequent publication challenged this claim, estimating the figure to be at least 40,000 species.[7] Although the highest estimates (up to 100 million species) have since been deprecated, estimates supported by [rarefaction curves](/source/Rarefaction_(ecology)),[8][9] together with the use of [DNA barcoding](/source/DNA_barcoding)[10] and the increasing acknowledgment of widespread [cryptic species](/source/Species_complex#cryptic_species) among nematodes,[11] have placed the figure closer to one million species.[12]

Nematodes have successfully adapted to nearly every [ecosystem](/source/Ecosystem): from marine (salt) to fresh water, soils, from the polar regions to the tropics, as well as the highest to the lowest of elevations. They are ubiquitous in freshwater, marine, and terrestrial environments, where they often outnumber other animals in both individual and [species](/source/Species) counts, and are found in locations as diverse as mountains, deserts, and [oceanic trenches](/source/Oceanic_trench). They are found in every part of the Earth's [lithosphere](/source/Lithosphere),[13] even at great depths, 0.9–3.6 km (3,000–12,000 ft) below the surface of the Earth in gold mines in South Africa.[13] They represent 90% of all animals on the [ocean floor](/source/Seabed).[14] In total, 4.4 × 1020 nematodes inhabit the Earth's topsoil, or approximately 60 billion for each human, with the highest densities observed in tundra and boreal forests.[15] Their numerical dominance, often exceeding a million individuals per square meter and accounting for about 80% of all individual animals on Earth, their diversity of lifecycles, and their presence at various trophic levels point to an important role in many ecosystems.[15][16] They play crucial roles in polar ecosystems.[17][18] The roughly 2,271 [genera](/source/Genera) are placed in 256 [families](/source/Family_(taxonomy)).[19] The many parasitic forms include [pathogens](/source/Pathogen) in most plants and animals. A third of the genera occur as parasites of [vertebrates](/source/Vertebrate); about 35 nematode species are [human parasites](/source/Human_parasite).[19]

## Etymology

The word *nematode* comes from the [Modern Latin](/source/Neo-Latin) compound of *nema-* 'thread' (from Greek *nema*, genitive *nematos* 'thread', from the stem *nein* 'to spin'; cf. *needle*) + *-odes* 'like, of the nature of' (cf. *-oid*). The addition firstly of '-oid' and then to '-ode' renders 'threadlike'.[20]

## Taxonomy and systematics

See also: [List of nematode families](/source/List_of_nematode_families)

		- *[Eophasma jurasicum](/source/Eophasma)*, a fossilized nematode

		- *[Caenorhabditis elegans](/source/Caenorhabditis_elegans)*

		- [Rhabditia](/source/Rhabditia)

		- *[Nippostrongylus brasiliensis](/source/Nippostrongylus_brasiliensis)*

		- Unidentified [Anisakidae](/source/Anisakidae) ([Ascaridina](/source/Ascaridina): [Ascaridoidea](https://en.wikipedia.org/w/index.php?title=Ascaridoidea&action=edit&redlink=1))

		- [Oxyuridae](/source/Oxyuridae) Pinworm

		- [Spiruridae](/source/Spiruridae) *[Dirofilaria immitis](/source/Dirofilaria_immitis)*

### History

 [Carl Linnaeus](/source/Carl_Linnaeus) described nematodes including the parasitic *[Dracunculus medinensis](/source/Dracunculus_medinensis)*, seen here under a person's skin.[21]

In 1758, [Carl Linnaeus](/source/Carl_Linnaeus) described nematodes of a few genera including *[Ascaris](/source/Ascaris)* and *[Dracunculus](/source/Dracunculus_(nematode))*, then included in the [Vermes](/source/Vermes).[21] The name of the group Nematoda, informally called "nematodes", came from [Nematoidea](/source/Nematoidea), originally defined by [Karl Rudolphi](/source/Karl_Rudolphi) in 1808,[22] from [Ancient Greek](/source/Ancient_Greek) νῆμα (*nêma, nêmatos*, 'thread') and -ειδής (*-eidēs*, 'species') (cf. native German [Fadenwurm](https://en.wiktionary.org/wiki/Fadenwurm) < [Faden](https://en.wiktionary.org/wiki/Faden) (*yarn, thread*) + [Wurm](https://en.wiktionary.org/wiki/Wurm), [attested since the mid of 18th](https://www.google.com/search?q=Fadenwurm%26sca_esv%3Df1b244d4c3767c15%26udm%3D36%26source%3Dlnt%26tbs%3Dcdr:1,cd_min:1/1/1500,cd_max:12/31/1750%26tbm%3D)). It was treated as [family](/source/Family_(taxonomy)) Nematodes by [Burmeister](/source/Hermann_Burmeister) in 1837.[22] At its origin, the "Nematoidea" erroneously included Nematodes and [Nematomorpha](/source/Nematomorpha), attributed by [Karl Theodor Ernst von Siebold](/source/Karl_Theodor_Ernst_von_Siebold) in 1843. Along with [Acanthocephala](/source/Acanthocephala), [Trematoda](/source/Trematoda), and [Cestoidea](/source/Cestoidea), it formed the obsolete group [Entozoa](/source/Entozoa),[23] created by Rudolphi in 1808.[24] They were classed along with Acanthocephala in the obsolete [phylum](/source/Phylum) [Nemathelminthes](/source/Aschelminth) by Gegenbaur in 1859.[22] In 1861, [Karl Moriz Diesing](/source/Karl_Moriz_Diesing) treated the group as order Nematoda.[22] In 1877, the [taxon](/source/Taxon) Nematoidea, including the family [Gordiidae](/source/Gordiidae) (horsehair worms), was promoted to the rank of phylum by [Ray Lankester](/source/Ray_Lankester).[22] The first clear distinction between the nemas and gordiids was realized by [František Vejdovsky](/source/Franti%C5%A1ek_Vejdovsky) when he named the group containing the horsehair worms the order Nematomorpha in 1886.[25]

In 1910, Grobben proposed the phylum Aschelminthes, and the nematodes were included as class Nematoda alongside the classes [Rotifera](/source/Rotifer), [Gastrotricha](/source/Gastrotrich), [Kinorhyncha](/source/Kinorhyncha), [Priapulida](/source/Priapulida), and [Nematomorpha](/source/Nematomorpha).[26]In 1919, [Nathan Cobb](/source/Nathan_Cobb) proposed that nematodes should be recognized alone as a phylum. He argued they should be called "nema" in English rather than "nematodes" and defined the taxon Nemates (later emended as Nemata, Latin plural of *nema*), listing Nematoidea *sensu restricto* as a synonym.[27] In 1932, Potts elevated the class Nematoda to the level of phylum, leaving the name the same. Although Potts' and Cobb's classifications are equivalent, both names are used, and Nematode became a popular term in zoological science.[28] However, some authors continued to accept phylum Aschelminthes in the second half of the 20th century.[29][30]

### Phylogeny

The [phylogenetic](/source/Phylogeny) relationships of the nematodes and their close relatives among the [protostomes](/source/Protostome) are still discussed. Initially, some morphology-based phylogenetic classifications accepted Aschelmithes/Nemathelminthes as a legitimate group.[31][32] In the 1990s, nematodes were proposed to form the group [Ecdysozoa](/source/Ecdysozoa) together with [moulting](/source/Moulting) animals, such as [arthropods](/source/Arthropod). The identity of the closest living relatives of the Nematoda has always been considered to be well resolved. Morphological and [molecular phylogenetics](/source/Molecular_phylogenetics) agree with placing the roundworms as a [sister taxon](/source/Sister_taxon) to the parasitic [Nematomorpha](/source/Nematomorpha); together, they make up the [Nematoida](/source/Nematoida). Along with the [Scalidophora](/source/Scalidophora) (formerly Cephalorhyncha), the Nematoida might form the clade [Cycloneuralia](/source/Cycloneuralia), but much disagreement occurs both between and among the available morphological and molecular data. The Cycloneuralia or the Introverta—depending on the validity of the former—are often ranked as a [superphylum](/source/Superphylum).[33][*[dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*] Recent molecular analyses have placed Nematoida closer to [Panarthropoda](/source/Panarthropoda) than to Scalidophora, forming clade Cryptovermes with the former.[34] However, a few studies have supported alternative hypotheses, grouping nematodes with [Tardigrada](/source/Tardigrade)[35] or with [Loricifera](/source/Loricifera).[36] Advancements in molecular phylogeny have also clarified the internal branchings of Nematoda.[35][37]

### Systematics

Due to the lack of knowledge regarding many nematodes, their systematics is contentious. An early and influential classification was proposed by Chitwood and Chitwood[38]—later revised by Chitwood[39]—who divided the phylum into two classes—[Aphasmidia](/source/Aphasmidia) and [Phasmidia](/source/Secernentea). These were later renamed [Adenophorea](/source/Adenophorea) (gland bearers) and [Secernentea](/source/Secernentea) (secretors), respectively.[40] The Secernentea share several characteristics, including the presence of [phasmids](/source/Phasmid_(nematode)), a pair of sensory organs located in the lateral posterior region, and this was used as the basis for this division. This scheme was adhered to in many later classifications, though the Adenophorea were not in a uniform group.

Initial studies of incomplete [DNA sequences](/source/Nucleic_acid_sequence)[41] suggested the existence of five [clades](/source/Clade):[42]

- [Dorylaimida](/source/Dorylaimida)

- [Enoplia](/source/Enoplia)

- [Spirurina](/source/Spirurina)

- [Tylenchina](/source/Tylenchina)

- [Rhabditina](/source/Rhabditina)

The Secernentea seem to be a natural group of close relatives, while the Adenophorea appear to be a [paraphyletic](/source/Paraphyletic) assemblage of roundworms that retain a good number of [ancestral traits](/source/Plesiomorph). The old [Enoplia](/source/Enoplia) do not seem to be monophyletic, either, but do contain two distinct lineages. The old group [Chromadorea](/source/Chromadorea) seems to be another paraphyletic assemblage, with the [Monhysterida](/source/Monhysterida) representing a very ancient minor group of nematodes. Among the Secernentea, the [Diplogasteria](/source/Diplogasteria) may need to be united with the [Rhabditia](/source/Rhabditia), while the Tylenchia might be paraphyletic with the Rhabditia.[43]

The understanding of roundworm systematics and [phylogeny](/source/Phylogeny) as of 2002 is summarised below:

**Phylum Nematoda**

- [Basal](/source/Basal_(evolution)) order [Monhysterida](/source/Monhysterida)

- Class [Dorylaimida](/source/Dorylaimida)

- Class [Enoplea](/source/Enoplea)

- Class [Secernentea](/source/Secernentea) - Subclass [Diplogasteria](/source/Diplogasteria) (disputed) - Subclass [Rhabditia](/source/Rhabditia) (paraphyletic?) - Subclass [Spiruria](/source/Spiruria) - Subclass [Tylenchia](https://en.wikipedia.org/w/index.php?title=Tylenchia&action=edit&redlink=1) (disputed)

- "[Chromadorea](/source/Chromadorea)" assemblage

Later work has suggested the presence of 12 clades.[44] In 2019, a study identified one [conserved signature indel](/source/Conserved_signature_indels) (CSI) found exclusively in members of the phylum Nematoda through comparative genetic analyses.[45] The CSI consists of a single amino acid insertion within a conserved region of a Na(+)/H(+) exchange regulatory factor protein NRFL-1 and is a molecular marker that distinguishes the phylum from other species.[45] An analysis of the mitochondrial DNA suggests that the following groupings are valid[46]

- subclass [Dorylaimia](/source/Dorylaimia)

- orders [Rhabditida](/source/Rhabditida), [Trichinellida](/source/Trichinellida) and [Mermithida](/source/Mermithida)

- suborder [Rhabditina](/source/Rhabditina)

- infraorders [Spiruromorpha](/source/Spiruromorpha) and [Oxyuridomorpha](/source/Oxyuridomorpha)

In 2022 a new classification of the entire phylum Nematoda was presented by M. Hodda. It was based on current molecular, developmental and morphological evidence.[47] Under this classification, the classes and subclasses are:

- Class [Enoplea](/source/Enoplea) - Subclass [Enoplia](/source/Enoplia) - Subclass [Oncholaimia](https://en.wikipedia.org/w/index.php?title=Oncholaimia&action=edit&redlink=1) - Subclass [Triplonchia](https://en.wikipedia.org/w/index.php?title=Triplonchia&action=edit&redlink=1)

- Class [Dorylaimida](/source/Dorylaimida) - Subclass [Dorylaimia](/source/Dorylaimia) - Subclass [Bathyodontia](https://en.wikipedia.org/w/index.php?title=Bathyodontia&action=edit&redlink=1) - Subclass [Trichocephalia](https://en.wikipedia.org/w/index.php?title=Trichocephalia&action=edit&redlink=1)

- Class [Chromadorea](/source/Chromadorea) - Subclass [Chromadoria](/source/Chromadoria) - Subclass [Plectia](https://en.wikipedia.org/w/index.php?title=Plectia&action=edit&redlink=1)

## Fossil record

Nematode eggs from the [clades](/source/Clade) Ascaridina, Spirurina, and Trichocephalida have been discovered in [coprolites](/source/Coprolite) from the [Oligocene](/source/Oligocene)-aged Tremembé Formation, which represented a [palaeolake](/source/Paleolake) in present-day [São Paulo](/source/S%C3%A3o_Paulo_(state)) with a diverse [fossil](/source/Fossil) assemblage of birds, fish, and arthropods that lent itself to fostering high nematode diversity.[48] Nematodes have also been found in various [lagerstätten](/source/Lagerst%C3%A4tte), such as [Burmese amber](/source/Burmese_amber), the [Moltrasio Formation](/source/Moltrasio_Formation), and the [Rhynie chert](/source/Rhynie_chert), where the earliest known fossils are known from.

## Anatomy

Internal anatomy of a male *C. elegans* nematode

Cross-section of female *[Ascaris](/source/Ascaris)*. The large circles filled with small green circles are the uterus and eggs. The long narrow feature is the [digestive tract](#Digestive_system). The smaller red and orange circles are the [ovaries](/source/Ovary) and [oviducts](/source/Oviduct). The cluster of green and black blobs in the upper right and lower left are the nerve cords ([ventral](/source/Ventral_nerve_cord) and [dorsal](/source/Dorsal_nerve_cord)). Surrounding the internal organs are the frilly green longitudinal muscles, the dark hypodermis, and the green outer [cuticle](/source/Cuticle#Cuticle_of_invertebrates).

Nematodes are very small, slender worms. Most are free-living, often less than 2.5 mm long and some only about 1 mm. Many nematodes are microscopic. Some soil nematodes can reach up to 7 mm in length, and some marine species can reach up to 5 cm. Some are parasitic and can reach lengths of 50 cm or more.[49]

The body is often ornamented with ridges, rings, bristles, or other distinctive structures.[50]

The head 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.[51] The [epidermis](/source/Epidermis_(zoology)) is either a [syncytium](/source/Syncytium) or a single layer of cells, and is covered by a thick [collagenous](/source/Collagen) [cuticle](/source/Cuticle). The cuticle is often of a complex structure and may have two or three distinct layers. Underneath the epidermis lies a layer of longitudinal [muscle](/source/Muscle) cells. The relatively rigid cuticle works with the muscles to create a hydroskeleton, as nematodes lack circumferential muscles. Projections run from the inner surface of muscle cells towards the [nerve cords](/source/Ventral_nerve_cord); this is a unique arrangement in the animal kingdom, in which nerve cells normally extend fibers into the muscles rather than *vice versa*.[51]

### Digestive system

The oral cavity is lined with cuticles, which are often strengthened with structures, such as ridges, especially in carnivorous species, which may bear several teeth. The mouth often includes a sharp [stylet](/source/Stylet_(zoology)), which the animal can thrust into its prey. In some species, the stylet is hollow and can be used to suck liquids from plants or animals.[51] The oral cavity opens into a muscular, sucking [pharynx](/source/Pharynx), also lined with cuticle. Digestive glands are found in this region of the gut, producing [enzymes](/source/Digestive_enzyme) that start to break down the food. In stylet-bearing species, these may even be injected into the prey.[51]

No [stomach](/source/Stomach) is present, with the pharynx connecting directly to a muscleless [intestine](/source/Intestine) that forms the main length of the gut. This produces further enzymes and also absorbs nutrients through its single-cell-thick lining. The last portion of the intestine is lined by a cuticle, forming a [rectum](/source/Rectum), which expels waste through the [anus](/source/Anus) just below and in front of the tip of the tail. The movement of food through the digestive system is the result of the body movements of the worm. The intestine has valves or [sphincters](/source/Sphincter) at either end to help control food movement through the body.[51]

### Excretory system

[Nitrogenous waste](/source/Nitrogenous_waste) is excreted in the form of [ammonia](/source/Ammonia) through the body wall, and is not associated with any specific organs. However, the structures for excreting salt to maintain [osmoregulation](/source/Osmoregulation) are typically more complex.[51]

There is an excretory gland, also known as a *ventral cell*, or *renette cell* in all species of Adenophorea. In Secernentia there is an excretory canal system that may or may not use a gland cell.[49]

### Nervous system

See also: [Muscle arms](/source/Muscle_arms)

At the anterior end of the animal a dense, circular [nerve ring](/source/Circumesophageal_nerve_ring) which serves as the [brain](/source/Brain) surrounds the pharynx.[51] From this ring six labial papillary nerve cords extend anteriorly, while six nerve cords; a large ventral, a smaller dorsal and two pairs of sublateral cords extend posteriorly.[52] Each nerve lies within a cord of connective tissue lying beneath the cuticle and between the muscle cells. The [ventral nerve](/source/Ventral_nerve_cord) is the largest, and has a double structure forward of the [excretory](/source/Excretion) [pore](https://en.wiktionary.org/wiki/pore). The dorsal nerve is responsible for motor control, while the lateral nerves are sensory, and the ventral combines both functions.[51]

The nervous system is the only place in the body that contains [cilia](/source/Cilia); these are all nonmotile and with a sensory function.[53][54]

The body is covered in numerous sensory [bristles](/source/Bristle) and papillae that together provide a sense of touch. Behind the sensory bristles on the head lie two small pits, or '[amphids](/source/Amphid)'. These are well supplied with nerve cells and are probably [chemoreception](/source/Chemoreceptor) organs. A few aquatic nematodes possess what appear to be [pigmented](/source/Pigment) eye-spots, but whether or not these are actually sensory in nature is unclear.[51]

## Reproduction

Extremity of a male nematode showing the [spicule](/source/Spicule_(nematode)), used for copulation, bar=100 μm[55]

Most nematode species are [dioecious](/source/Dioecious), with separate male and female individuals, though some, such as *[Caenorhabditis elegans](/source/Caenorhabditis_elegans)*, are [androdioecious](/source/Androdioecious), consisting of [hermaphrodites](/source/Hermaphrodite) and rare males. Both sexes possess one or two tubular [gonads](/source/Gonad). In males, the sperm are produced at the end of the gonad and migrate along its length as they mature. The testis opens into a relatively wide [seminal vesicle](/source/Seminal_vesicle) and then during intercourse into a glandular and muscular ejaculatory duct associated with the [vas deferens](/source/Vas_deferens) and [cloaca](/source/Cloaca). In females, the ovaries each open into an [oviduct](/source/Oviduct) (in hermaphrodites, the eggs enter a [spermatheca](/source/Spermatheca) first) and then a glandular [uterus](/source/Uterus). The uteri both open into a common vulva/vagina, usually located in the middle of the morphologically ventral surface.[51]

Reproduction is usually sexual, though hermaphrodites are capable of self-fertilization. Males are usually smaller than females or hermaphrodites (often much smaller) and often have a characteristically bent or fan-shaped tail. During [copulation](/source/Copulation_(zoology)), one or more [chitinized](/source/Chitin) [spicules](/source/Spicule_(nematode)) move out of the cloaca and are inserted into the genital pore of the female. [Amoeboid](/source/Amoeboid) [sperm](/source/Sperm) crawl along the spicule into the female worm. Nematode sperm is thought to be the only [eukaryotic cell](/source/Eukaryotic_cell) without the globular protein [G-actin](/source/G-actin).[56]

Eggs may be [embryonated](/source/Embryonated) or unembryonated when passed by the female, meaning their fertilized eggs may not yet be developed. A few species are known to be [ovoviviparous](/source/Ovoviviparous). The eggs are protected by an outer shell, secreted by the uterus. In free-living roundworms, the eggs hatch into [larvae](/source/Larva), which appear essentially identical to the adults, except for an underdeveloped reproductive system; in parasitic roundworms, the lifecycle is often much more complicated.[51] The structure of the eggshell is complicated and includes several layers; a detailed anatomical and terminological framework has been proposed for these layers in 2023.[57]

Nematodes as a whole possess a wide range of modes of reproduction.[58] Some nematodes, such as *[Heterorhabditis](/source/Heterorhabditis)* spp., undergo a process called [endotokia matricida](/source/Endotokia_matricida): intrauterine birth causing maternal death.[59] Some nematodes are [hermaphroditic](/source/Hermaphrodite), and keep their self-fertilized eggs inside the [uterus](/source/Uterus) until they hatch. The juvenile nematodes then ingest the parent nematode. This process is significantly promoted in environments with a low food supply.[59]

The nematode model species *C. elegans*, *[C. briggsae](/source/Caenorhabditis_briggsae)*, and *[Pristionchus pacificus](/source/Pristionchus_pacificus)*, among other species, exhibit [androdioecy](/source/Androdioecy),[60] which is otherwise very rare among animals. The single [genus](/source/Genus) *[Meloidogyne](/source/Meloidogyne)* (root-knot nematodes) exhibits a range of reproductive modes, including [sexual reproduction](/source/Sexual_reproduction), facultative sexuality (in which most, but not all, generations reproduce asexually), and both [meiotic](/source/Meiosis) and [mitotic](/source/Mitosis) [parthenogenesis](/source/Parthenogenesis).[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*]

The genus *[Mesorhabditis](/source/Mesorhabditis)* exhibits an unusual form of parthenogenesis, in which sperm-producing males copulate with females, but the sperm do not fuse with the ovum. Contact with the sperm is essential for the ovum to begin dividing, but because no fusion of the cells occurs, the male contributes no genetic material to the offspring, which are essentially [clones](/source/Cloning) of the female.[51]

## Aging

The nematode *[Caenorhabditis elegans](/source/Caenorhabditis_elegans)* is often used as a model organism for studying [aging](/source/Ageing) at the molecular level. For example, in *C. elegans* aging negatively impacts [DNA repair](/source/DNA_repair), and mutants of *C. elegans* that are long-lived were shown to have increased DNA repair capability.[61] These findings suggest a genetically determined correlation between DNA repair capacity and lifespan.[61] In female *C. elegans*, [germline](/source/Germline) processes that control DNA repair and formation of [chromosomal crossovers](/source/Chromosomal_crossover) during [meiosis](/source/Meiosis) were shown to progressively deteriorate with age.[62]

## Free-living species

Different free-living species feed on materials as varied as [bacteria](/source/Bacteria), [algae](/source/Algae), [fungi](/source/Fungi), small animals, fecal matter, dead organisms, and living tissues. Free-living marine nematodes are important and abundant members of the [meiobenthos](/source/Meiobenthos). They play an important role in the decomposition process, aid in recycling of nutrients in marine environments, and are sensitive to changes in the environment caused by pollution. One roundworm of note, [*C. elegans*](/source/Caenorhabditis_elegans), lives in the soil and has found much use as a [model organism](/source/Model_organism). *C. elegans* has had its entire genome sequenced,[63] the developmental fate of every cell determined, and every neuron mapped.[64]

## Parasitic species

[Fecal](/source/Fecal) parasitic (mostly) nematodes from stools of [Old World monkeys](/source/Old_World_monkey)

Nematodes that commonly parasitise humans include [ascarids](/source/Ascarid) (*Ascaris*), [filarias](/source/Filaria), [hookworms](/source/Hookworm), [pinworms](/source/Pinworm_(parasite)) (*Enterobius*), and [whipworms](/source/Whipworm) (*Trichuris trichiura*). The species *[Trichinella spiralis](/source/Trichinella_spiralis)*, commonly known as the trichina worm, occurs in rats, pigs, bears, and humans, and is responsible for the disease [trichinosis](/source/Trichinosis). *[Baylisascaris](/source/Baylisascaris)* usually infests wild animals, but can be deadly to humans, as well. *[Dirofilaria immitis](/source/Dirofilaria_immitis)* is known for causing heartworm disease by inhabiting the hearts, arteries, and lungs of dogs and some cats. *[Haemonchus contortus](/source/Haemonchus_contortus)* is one of the most abundant infectious agents in sheep around the world, causing great economic damage to sheep. In contrast, [entomopathogenic nematodes](/source/Entomopathogenic_nematode) parasitize insects and are mostly considered beneficial by humans, but some attack beneficial insects.[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*]

One form of nematode is entirely dependent upon [fig wasps](/source/Fig_wasp), which are the sole source of [fig](/source/Ficus) fertilization. They prey upon the wasps, riding them from the ripe fig of the wasp's birth to the fig flower of its death, where they kill the wasp, and their offspring await the birth of the next generation of wasps as the fig ripens.[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*]

Colorized [electron micrograph](/source/Electron_micrograph) of [soybean cyst nematode](/source/Soybean_cyst_nematode) (*Heterodera glycines*) and egg

A parasitic [tetradonematid](/source/Tetradonematidae) nematode discovered in 2005, *[Myrmeconema neotropicum](/source/Myrmeconema_neotropicum)*, induces fruit mimicry in the tropical ant *[Cephalotes atratus](/source/Cephalotes_atratus)*. Infected ants develop bright red [gasters](/source/Gaster_(insect_anatomy)) (abdomens), tend to be more sluggish, and walk with their gasters in a conspicuous elevated position. These changes likely cause [frugivorous](/source/Frugivorous) birds to confuse the infected ants for berries, and eat them. Parasite eggs passed in the bird's [feces](/source/Feces) are subsequently collected by foraging *C. atratus* and are fed to their [larvae](/source/Larva), thus completing the lifecycle of *M. neotropicum*.[65]

Similarly, multiple varieties of nematodes have been found in the abdominal cavities of the primitively social sweat bee, *[Lasioglossum zephyrus](/source/Lasioglossum_zephyrus)*. Inside the female body, the nematode hinders ovarian development and renders the bee less active, thus less effective in pollen collection.[66]

### Agriculture and horticulture

Depending on its species, a nematode may be beneficial or detrimental to plant health. From agricultural and [horticulture](/source/Horticulture) perspectives, the two categories of nematodes are the predatory ones, which kill garden pests; and the pest nematodes, which attack plants, or act as [vectors](/source/Vector_(epidemiology)) spreading [plant viruses](/source/Plant_virus) between crop plants.[67] Predatory nematodes include *[Phasmarhabditis hermaphrodita](/source/Phasmarhabditis_hermaphrodita)* which is a lethal parasite of gastropods such as [slugs](/source/Slug) and [snails](/source/Snail).[68] Some members of the genus *[Steinernema](/source/Steinernema)* such as *[Steinernema carpocapsae](/source/Steinernema_carpocapsae)* and *[Steinernema riobrave](/source/Steinernema_riobrave)* are generalist parasites of [webworms](/source/Webworm), [cutworms](/source/Cutworm), armyworms, [girdlers](/source/Oncideres_cingulata), some [weevils](/source/Weevil), [wood-borers](/source/Woodboring_beetle) and [corn earworm moths](/source/Helicoverpa_zea).[69] These organisms are grown commercially as [biological pest control](/source/Biological_pest_control) agents which can be used as an alternative to [pesticides](/source/Pesticides); their use is considered very safe.[70] Plant-parasitic nematodes include several groups causing severe crop losses, taking 10% of crops worldwide every year.[71] The most common genera are *[Aphelenchoides](/source/Aphelenchoides)* ([foliar nematodes](/source/Foliar_nematode)), *[Ditylenchus](/source/Ditylenchus)*, *[Globodera](/source/Globodera)* (potato cyst nematodes), *[Heterodera](/source/Heterodera)* (soybean cyst nematodes), *[Longidorus](/source/Longidorus)*, *[Meloidogyne](/source/Meloidogyne)* ([root-knot nematodes](/source/Root-knot_nematodes)), *[Nacobbus](/source/Nacobbus)*, *[Pratylenchus](/source/Pratylenchus)* (lesion nematodes), *[Trichodorus](/source/Trichodorus)*, and *[Xiphinema](/source/Xiphinema)* (dagger nematodes). Several phytoparasitic nematode species cause histological damages to roots, including the formation of visible galls (e.g. by root-knot nematodes), which are useful characters for their diagnostic in the field. Some nematode species transmit plant viruses through their feeding activity on roots. One of them is *[Xiphinema index](/source/Xiphinema_index)*, vector of [grapevine fanleaf virus](/source/Grapevine_fanleaf_virus), an important disease of grapes, another one is *[Xiphinema diversicaudatum](/source/Xiphinema_diversicaudatum)*, vector of [arabis mosaic virus](/source/Arabis_mosaic_virus)*.* Other nematodes attack bark and forest trees. The most important representative of this group is *[Bursaphelenchus xylophilus](/source/Bursaphelenchus_xylophilus)*, the pine wood nematode, present in Asia and America and recently discovered in Europe. This nematode is transmitted from tree to tree by sawyer beetles (*[Monochamus](/source/Monochamus)*).[72]

Greenhouse growers use [entomopathogenic nematodes](/source/Entomopathogenic_nematode) as beneficial agents to control [fungus gnats](/source/Fungus_gnat). The nematodes enter the larvae of the gnats by way of their anus, mouth, and [spiracles](/source/Spiracle_(arthropods)) (breathing pores) and then release [bacteria](/source/Bacteria) which kills the gnat larvae. Commonly used nematode species to control pests on greenhouse crops include *[Steinernema](/source/Steinernema) feltiae* for fungus gnats and [western flower thrips](/source/Western_flower_thrips), *[Steinernema carpocapsae](/source/Steinernema_carpocapsae)* used to control shore flies, *Steinernema kraussei* for control of [black vine weevils](/source/Vine_weevil), and *[Heterorhabditis bacteriophora](/source/Heterorhabditis_bacteriophora)* to control beetle larvae.[73]

Rotations of plants with nematode-resistant species or varieties is one means of managing parasitic nematode infestations. For example, planting [Tagetes marigolds](/source/Tagetes) as a cover crop just prior to planting a nematode-susceptible plant, has been shown to suppress nematodes.[74] Another approach involves using natural antagonists, particularly bacteria and fungi, which have proven effective in suppressing plant-parasitic nematodes,[75] such as the fungus *[Gliocladium roseum](/source/Gliocladium_roseum)*. [Chitosan](/source/Chitosan), a natural [biocontrol](/source/Biological_pest_control), elicits plant defense responses to destroy parasitic [cyst](/source/Cyst) nematodes on roots of [soybean](/source/Soybean), [maize](/source/Maize), [sugar beet](/source/Sugar_beet), [potato](/source/Potato), and [tomato](/source/Tomato) crops without harming beneficial nematodes in the soil.[76] [Soil steaming](/source/Soil_steam_sterilization) is an efficient method to kill nematodes before planting a crop, but indiscriminately eliminates both harmful and beneficial soil fauna.

The golden nematode *[Globodera rostochiensis](/source/Globodera_rostochiensis)* is a particularly harmful pest that has resulted in quarantines and crop failures worldwide. It can be controlled, however. [CSIRO](/source/CSIRO), the scientific research body of the Australian government, found a 13- to 14-fold reduction of nematode population densities in plots having [Chinese mustard](/source/Chinese_mustard) *[Brassica juncea](/source/Brassica_juncea)* green manure or seed meal in the soil.[77]

### Disease in humans

[Disability-adjusted life year](/source/Disability-adjusted_life_year) for intestinal nematode infections per 100,000 in 2002.

    <  25

  25–50

  50–75

  75–100

  100–120

  120–140

  140–160

  160–180

  180–200

  200–220

  220–240

    >  240

  no data

[Anthelmintic](/source/Anthelmintic) effect of [papain](/source/Papain) on *[Heligmosomoides bakeri](/source/Heligmosomoides_bakeri)*

A number of pathogenic intestinal nematodes cause diseases in humans, including [ascariasis](/source/Ascariasis), [trichuriasis](/source/Trichuriasis), and [hookworm disease](/source/Hookworm_disease). *[Anisakis](/source/Anisakis)* species parasitise fish and [marine mammals](/source/Marine_mammal) and when consumed by humans can cause [anisakiasis](/source/Anisakiasis), a [gastric](/source/Gastric) or gastroallergic disease.[78] Gastrointestinal nematode infections in humans are common, with approximately 50% of the global population being affected. Developing countries are most heavily impacted, in part due to lack of access to medical care.[79]

[Trichinosis](/source/Trichinosis) starts in the intestines but larvae can migrate to muscle. *[Filarial](/source/Filaria)* nematodes cause [filariases](/source/Filariasis).

[Toxocariasis](/source/Toxocariasis) is a [zoonotic](/source/Zoonotic) infection caused by roundworms passed from dogs, and sometimes cats. It can give rise to different types of *larva migrans*, such as [visceral larva migrans](/source/Visceral_larva_migrans) and [ocular larva migrans](/source/Ocular_larva_migrans).

Studies have shown that parasitic nematodes infect [American eels](/source/American_eel), causing damage to the eel's swim bladder,[80] dairy animals like cattle and buffalo,[81] and all species of sheep.[82]

## Soil ecosystems

Further information: [Soil ecology](/source/Soil_ecology)

About 90% of nematodes reside in the top 15 cm (6") of soil. Nematodes do not decompose organic matter, but, instead, are parasitic and free-living organisms that feed on living material. Nematodes can effectively regulate bacterial population and community composition—they may eat up to 5,000 bacteria per minute. Also, nematodes can play an important role in the [nitrogen cycle](/source/Nitrogen_cycle) by way of nitrogen mineralization.[83] But plant parasitic nematodes cause billions of dollars in annual crop damage worldwide.[84]

One group of [carnivorous fungi](/source/Carnivorous_fungus), the [nematophagous fungi](/source/Nematophagous_fungus), are predators of soil nematodes.[85] They can set enticements for the nematodes in the form of lassos or adhesive structures.[86][87][88] They can also release powerful toxins when in contact with nematodes.[89]

## Survivability

See also: [List of longest-living organisms § Revived into activity after stasis](/source/List_of_longest-living_organisms#Revived_into_activity_after_stasis)

The nematode *[Caenorhabditis elegans](/source/Caenorhabditis_elegans)* an important [model organism](/source/Model_organism), was used as part of an ongoing research project conducted on the 2003 [Space Shuttle *Columbia*](/source/Space_Shuttle_Columbia) mission [STS-107](/source/STS-107), and survived the [re-entry breakup](/source/Space_Shuttle_Columbia_disaster#Recovery_of_debris). It is believed to be the first known species to survive a virtually unprotected atmospheric descent to Earth's surface.[90][91] The Antarctic nematode *[Panagrolaimus](/source/Panagrolaimus) davidi* was able to withstand intracellular freezing depending on how well it had been fed.[92] In 2023 an individual of *[Panagrolaimus kolymaensis](/source/Panagrolaimus_kolymaensis)* was revived after 46,000 years in Siberian permafrost.[93]

## See also

- [Biological pest control](/source/Biological_pest_control) – Controlling pests using other organisms

- [List of organic gardening and farming topics](/source/List_of_organic_gardening_and_farming_topics) – Overview of and topical guide to organic gardening and farmingPages displaying short descriptions of redirect targets

- [List of parasites of humans](/source/List_of_parasites_of_humans)

- [Nematode.net](/source/Nematode.net)

- [Soil food web](/source/Soil_food_web)

- [Worm bagging](/source/Worm_bagging) – Form of pathological egg retention observed in nematodes

## References

1. **[^](#cite_ref-1)** Poinar, George; Kerp, Hans; Hass, Hagen (January 2008). ["*Palaeonema phyticum* gen. n., sp. n. (Nematoda: Palaeonematidae fam. n.), a Devonian nematode associated with early land plants"](https://brill.com/view/journals/nemy/10/1/article-p9_2.xml). *Nematology*. **10** (1): 9–14. [Bibcode](/source/Bibcode_(identifier)):[2008Nemat..10....9P](https://ui.adsabs.harvard.edu/abs/2008Nemat..10....9P). [doi](/source/Doi_(identifier)):[10.1163/156854108783360159](https://doi.org/10.1163%2F156854108783360159).

1. **[^](#cite_ref-2)** Maas, Andreas; Waloszek, Dieter; Haug, Joachim; Müller, Klaus (January 2007). ["A possible larval roundworm from the Cambrian 'Orsten' and its bearing on the phylogeny of Cycloneuralia"](https://www.researchgate.net/publication/238695144). *Memoirs of the Association of Australasian Palaeontologists*. **34**: 499–519.

1. **[^](#cite_ref-3)** Baker, Emily A.; Woollard, Alison (2019). ["How weird is the worm? Evolution of the developmental gene toolkit in *Caenorhabditis elegans*"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956190). *[Journal of Developmental Biology](/source/Journal_of_Developmental_Biology)*. **7** (4): 19. [doi](/source/Doi_(identifier)):[10.3390/jdb7040019](https://doi.org/10.3390%2Fjdb7040019). [PMC](/source/PMC_(identifier)) [6956190](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956190). [PMID](/source/PMID_(identifier)) [31569401](https://pubmed.ncbi.nlm.nih.gov/31569401).

1. **[^](#cite_ref-4)** Hodda, M. (2011). Zhang, Z.-Q. (ed.). "Phylum Nematoda (Cobb, 1932)". Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness. *[Zootaxa](/source/Zootaxa)*. **3148**: 63–95. [doi](/source/Doi_(identifier)):[10.11646/zootaxa.3148.1.11](https://doi.org/10.11646%2Fzootaxa.3148.1.11).

1. **[^](#cite_ref-5)** Zhang, Z. (2013). Zhang, Z.-Q. (ed.). ["Animal biodiversity: An update of classification and diversity in 2013"](https://doi.org/10.11646%2Fzootaxa.3703.1.3). Animal biodiversity: An update of classification and diversity (Addenda 2013). *[Zootaxa](/source/Zootaxa)*. **3703** (1): 5–11. [doi](/source/Doi_(identifier)):[10.11646/zootaxa.3703.1.3](https://doi.org/10.11646%2Fzootaxa.3703.1.3).

1. **[^](#cite_ref-Lambshead-1993_6-0)** Lambshead, P. John D. (January 1993). ["Recent developments in marine benthic biodiversity research"](https://www.researchgate.net/publication/279896164). *[Oceanis](https://en.wikipedia.org/w/index.php?title=Oceanis&action=edit&redlink=1)*. **19** (6): 5–24. Retrieved 5 November 2018.

1. **[^](#cite_ref-RAnderson_7-0)** Anderson, Roy C. (2000). [*Nematode Parasites of Vertebrates: Their Development and Transmission*](https://books.google.com/books?id=lEERbfsvP1EC&pg=PA1). CABI. pp. 1–2. [doi](/source/Doi_(identifier)):[10.1079/9780851994215.0000](https://doi.org/10.1079%2F9780851994215.0000). [ISBN](/source/ISBN_(identifier)) [978-0-85199-421-5](https://en.wikipedia.org/wiki/Special:BookSources/978-0-85199-421-5). [OCLC](/source/OCLC_(identifier)) [559243334](https://search.worldcat.org/oclc/559243334). Estimates of 500,000 to a million species have no basis in fact.

1. **[^](#cite_ref-Lambshead_Boucher_8-0)** Lambshead, P.J.; Boucher, G. (2003). ["Marine nematode deep-sea biodiversity—hyperdiverse or hype?"](https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2699.2003.00843.x). *Journal of Biogeography*. **30** (4): 475–485. [Bibcode](/source/Bibcode_(identifier)):[2003JBiog..30..475L](https://ui.adsabs.harvard.edu/abs/2003JBiog..30..475L). [doi](/source/Doi_(identifier)):[10.1046/j.1365-2699.2003.00843.x](https://doi.org/10.1046%2Fj.1365-2699.2003.00843.x). [S2CID](/source/S2CID_(identifier)) [86504164](https://api.semanticscholar.org/CorpusID:86504164).

1. **[^](#cite_ref-Qing_Bert_9-0)** Qing, X.; Bert, W. (2019). ["Family Tylenchidae (Nematoda): an overview and perspectives"](https://link.springer.com/article/10.1007/s13127-019-00404-4). *Organisms Diversity & Evolution*. **19** (3): 391–408. [Bibcode](/source/Bibcode_(identifier)):[2019ODivE..19..391Q](https://ui.adsabs.harvard.edu/abs/2019ODivE..19..391Q). [doi](/source/Doi_(identifier)):[10.1007/s13127-019-00404-4](https://doi.org/10.1007%2Fs13127-019-00404-4). [S2CID](/source/S2CID_(identifier)) [190873905](https://api.semanticscholar.org/CorpusID:190873905).

1. **[^](#cite_ref-Floyd2002_10-0)** Floyd, Robin; Abebe, Eyualem; Papert, Artemis; Blaxter, Mark (2002). ["Molecular barcodes for soil nematode identification"](https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-294X.2002.01485.x?sid=nlm%3Apubmed). *Molecular Ecology*. **11** (4): 839–850. [Bibcode](/source/Bibcode_(identifier)):[2002MolEc..11..839F](https://ui.adsabs.harvard.edu/abs/2002MolEc..11..839F). [doi](/source/Doi_(identifier)):[10.1046/j.1365-294X.2002.01485.x](https://doi.org/10.1046%2Fj.1365-294X.2002.01485.x). [PMID](/source/PMID_(identifier)) [11972769](https://pubmed.ncbi.nlm.nih.gov/11972769). [S2CID](/source/S2CID_(identifier)) [12955921](https://api.semanticscholar.org/CorpusID:12955921).

1. **[^](#cite_ref-Derycke_et_al_11-0)** Derycke, S.; Sheibani Tezerji, R.; Rigaux, A.; Moens, T. (2012). ["Investigating the ecology and evolution of cryptic marine nematode species through quantitative real-time PCR of the ribosomal ITS region"](https://biblio.ugent.be/publication/3127487). *Molecular Ecology Resources*. **12** (4): 607–619. [Bibcode](/source/Bibcode_(identifier)):[2012MolER..12..607D](https://ui.adsabs.harvard.edu/abs/2012MolER..12..607D). [doi](/source/Doi_(identifier)):[10.1111/j.1755-0998.2012.03128.x](https://doi.org/10.1111%2Fj.1755-0998.2012.03128.x). [hdl](/source/Hdl_(identifier)):[1854/LU-3127487](https://hdl.handle.net/1854%2FLU-3127487). [PMID](/source/PMID_(identifier)) [22385909](https://pubmed.ncbi.nlm.nih.gov/22385909). [S2CID](/source/S2CID_(identifier)) [4818657](https://api.semanticscholar.org/CorpusID:4818657).

1. **[^](#cite_ref-Blaxter2016_12-0)** Blaxter, Mark (2016). ["Imagining Sisyphus happy: DNA barcoding and the unnamed majority"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4971181). *Philosophical Transactions of the Royal Society of London B*. **371** (1702) 20150329. [doi](/source/Doi_(identifier)):[10.1098/rstb.2015.0329](https://doi.org/10.1098%2Frstb.2015.0329). [PMC](/source/PMC_(identifier)) [4971181](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4971181). [PMID](/source/PMID_(identifier)) [27481781](https://pubmed.ncbi.nlm.nih.gov/27481781).

1. ^ [***a***](#cite_ref-Borgonie_2011_13-0) [***b***](#cite_ref-Borgonie_2011_13-1) Borgonie, G.; García-Moyano, A.; Litthauer, D.; Bert, W.; Bester, A.; van Heerden, E.; Möller, C.; Erasmus, M.; Onstott, T. C. (June 2011). ["Nematoda from the terrestrial deep subsurface of South Africa"](https://biblio.ugent.be/publication/1269676). *Nature*. **474** (7349): 79–82. [Bibcode](/source/Bibcode_(identifier)):[2011Natur.474...79B](https://ui.adsabs.harvard.edu/abs/2011Natur.474...79B). [doi](/source/Doi_(identifier)):[10.1038/nature09974](https://doi.org/10.1038%2Fnature09974). [hdl](/source/Hdl_(identifier)):[1854/LU-1269676](https://hdl.handle.net/1854%2FLU-1269676). [PMID](/source/PMID_(identifier)) [21637257](https://pubmed.ncbi.nlm.nih.gov/21637257). [S2CID](/source/S2CID_(identifier)) [4399763](https://api.semanticscholar.org/CorpusID:4399763).

1. **[^](#cite_ref-pmid18164201_14-0)** Danovaro, Roberto; Gambi, Cristina; Dell'Anno, Antonio; Corinaldesi, Cinzia; Fraschetti, Simonetta; Vanreusel, Ann; Vincx, Magda; Gooday, Andrew J. (2008). ["Exponential Decline of Deep-Sea Ecosystem Functioning Linked to Benthic Biodiversity Loss"](http://www.cell.com/article/S0960982207023421/pdf). *Current Biology*. **18** (1): 1–8. [Bibcode](/source/Bibcode_(identifier)):[2008CBio...18....1D](https://ui.adsabs.harvard.edu/abs/2008CBio...18....1D). [doi](/source/Doi_(identifier)):[10.1016/j.cub.2007.11.056](https://doi.org/10.1016%2Fj.cub.2007.11.056). [PMID](/source/PMID_(identifier)) [18164201](https://pubmed.ncbi.nlm.nih.gov/18164201). Retrieved 21 December 2024.

1. ^ [***a***](#cite_ref-:0_15-0) [***b***](#cite_ref-:0_15-1) van den Hoogen, Johan; Geisen, Stefan; Routh, Devin; Ferris, Howard; Traunspurger, Walter; et al. (24 July 2019). ["Soil nematode abundance and functional group composition at a global scale"](https://web.archive.org/web/20200302112231/https://gitlab.ethz.ch/devinrouth/crowther_lab_nematodes). *Nature*. **572** (7768): 194–198. [Bibcode](/source/Bibcode_(identifier)):[2019Natur.572..194V](https://ui.adsabs.harvard.edu/abs/2019Natur.572..194V). [doi](/source/Doi_(identifier)):[10.1038/s41586-019-1418-6](https://doi.org/10.1038%2Fs41586-019-1418-6). [hdl](/source/Hdl_(identifier)):[20.500.11755/c8c7bc6a-585c-4a13-9e36-4851939c1b10](https://hdl.handle.net/20.500.11755%2Fc8c7bc6a-585c-4a13-9e36-4851939c1b10). [PMID](/source/PMID_(identifier)) [31341281](https://pubmed.ncbi.nlm.nih.gov/31341281). [S2CID](/source/S2CID_(identifier)) [198492891](https://api.semanticscholar.org/CorpusID:198492891). Archived from [the original](https://gitlab.ethz.ch/devinrouth/crowther_lab_nematodes) on 2 March 2020. Retrieved 10 December 2019.

1. **[^](#cite_ref-isbn0-903874-22-9_16-0)** Platt, H.M. (1994). "foreword". In Lorenzen, S.; Lorenzen, S.A. (eds.). *The phylogenetic systematics of freeliving nematodes*. Ray Society (Series). Vol. 162. London, UK: Ray Society. [ISBN](/source/ISBN_(identifier)) [978-0-903874-22-9](https://en.wikipedia.org/wiki/Special:BookSources/978-0-903874-22-9). [OCLC](/source/OCLC_(identifier)) [1440106662](https://search.worldcat.org/oclc/1440106662).

1. **[^](#cite_ref-17)** Lee, Charles K.; Laughlin, Daniel C.; Bottos, Eric M.; Caruso, Tancredi; Joy, Kurt; et al. (15 February 2019). ["Biotic interactions are an unexpected yet critical control on the complexity of an abiotically driven polar ecosystem"](https://www.nature.com/articles/s42003-018-0274-5.pdf) (PDF). *Communications Biology*. **2** (1): 62. [Bibcode](/source/Bibcode_(identifier)):[2019CmBio...2...62L](https://ui.adsabs.harvard.edu/abs/2019CmBio...2...62L). [doi](/source/Doi_(identifier)):[10.1038/s42003-018-0274-5](https://doi.org/10.1038%2Fs42003-018-0274-5). [ISSN](/source/ISSN_(identifier)) [2399-3642](https://search.worldcat.org/issn/2399-3642). [PMC](/source/PMC_(identifier)) [6377621](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6377621). [PMID](/source/PMID_(identifier)) [30793041](https://pubmed.ncbi.nlm.nih.gov/30793041). Retrieved 21 December 2024.

1. **[^](#cite_ref-18)** Caruso, Tancredi; Hogg, Ian D.; Nielsen, Uffe N.; Bottos, Eric M.; Lee, Charles K.; Hopkins, David W.; Cary, S. Craig; Barrett, John E.; Green, T. G. Allan; Storey, Bryan C.; Wall, Diana H.; Adams, Byron J. (15 February 2019). ["Nematodes in a polar desert reveal the relative role of biotic interactions in the coexistence of soil animals"](https://www.nature.com/articles/s42003-018-0260-y.pdf) (PDF). *Communications Biology*. **2** (1): 63. [Bibcode](/source/Bibcode_(identifier)):[2019CmBio...2...63C](https://ui.adsabs.harvard.edu/abs/2019CmBio...2...63C). [doi](/source/Doi_(identifier)):[10.1038/s42003-018-0260-y](https://doi.org/10.1038%2Fs42003-018-0260-y). [ISSN](/source/ISSN_(identifier)) [2399-3642](https://search.worldcat.org/issn/2399-3642). [PMC](/source/PMC_(identifier)) [6377602](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6377602). [PMID](/source/PMID_(identifier)) [30793042](https://pubmed.ncbi.nlm.nih.gov/30793042). Retrieved 21 December 2024.

1. ^ [***a***](#cite_ref-n_19-0) [***b***](#cite_ref-n_19-1) Anderson, Roy C. (8 February 2000). [*Nematode Parasites of Vertebrates: Their development and transmission*](https://books.google.com/books?id=lEERbfsvP1EC). CABI. p. 1. [ISBN](/source/ISBN_(identifier)) [978-0-85199-786-5](https://en.wikipedia.org/wiki/Special:BookSources/978-0-85199-786-5).

1. **[^](#cite_ref-Name_20-0)** ["Phylum Name"](http://nemaplex.ucdavis.edu/General/Phylumname.htm). *nemaplex.ucdavis.edu*. Retrieved 23 December 2024.

1. ^ [***a***](#cite_ref-Cox_2002_21-0) [***b***](#cite_ref-Cox_2002_21-1) Cox, F. E. G. (2002). ["History of Human Parasitology"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC126866). *Clinical Microbiology Reviews*. **15** (4): 595–612. [Bibcode](/source/Bibcode_(identifier)):[2002CliMR..15..595C](https://ui.adsabs.harvard.edu/abs/2002CliMR..15..595C). [doi](/source/Doi_(identifier)):[10.1128/CMR.15.4.595-612.2002](https://doi.org/10.1128%2FCMR.15.4.595-612.2002). [PMC](/source/PMC_(identifier)) [126866](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC126866). [PMID](/source/PMID_(identifier)) [12364371](https://pubmed.ncbi.nlm.nih.gov/12364371).

1. ^ [***a***](#cite_ref-Chitwood_1957_22-0) [***b***](#cite_ref-Chitwood_1957_22-1) [***c***](#cite_ref-Chitwood_1957_22-2) [***d***](#cite_ref-Chitwood_1957_22-3) [***e***](#cite_ref-Chitwood_1957_22-4) Chitwood, B.G. (1957). "The English word "Nema" revised". *Systematic Biology*. **4** (45): 1619. [doi](/source/Doi_(identifier)):[10.2307/sysbio/6.4.184](https://doi.org/10.2307%2Fsysbio%2F6.4.184).

1. **[^](#cite_ref-isbn0-85199-202-1_23-0)** Siddiqi, M.R. (2000). "Introduction, Historical Review and Techniques". *Tylenchida: Parasites of plants and insects*. CABI. pp. 23–29. [ISBN](/source/ISBN_(identifier)) [978-0-85199-202-0](https://en.wikipedia.org/wiki/Special:BookSources/978-0-85199-202-0).

1. **[^](#cite_ref-24)** Schmidt-Rhaesa, A. (2014). "Gastrotricha, Cycloneuralia, and Gnathifera: General history and phylogeny". In Schmidt-Rhaesa, A. (ed.). *Handbook of Zoology (founded by W. Kükenthal)*. Vol. 1, Nematomorpha, Priapulida, Kinorhyncha, Loricifera. Berlin, Boston: de Gruyter.

1. **[^](#cite_ref-Bleidorn_2002_25-0)** Bleidorn, Christoph; Schmidt-Rhaesa, Andreas; Garey, James R. (2002). ["Systematic relationships of Nematomorpha based on molecular and morphological data"](https://doi.org/10.1111%2Fj.1744-7410.2002.tb00136.x). *Invertebrate Biology*. **121** (4): 357–364. [Bibcode](/source/Bibcode_(identifier)):[2002InvBi.121..357B](https://ui.adsabs.harvard.edu/abs/2002InvBi.121..357B). [doi](/source/Doi_(identifier)):[10.1111/j.1744-7410.2002.tb00136.x](https://doi.org/10.1111%2Fj.1744-7410.2002.tb00136.x).

1. **[^](#cite_ref-Marcus_1958_26-0)** Marcus, Ernesto (1958). "On the Evolution of the Animal Phyla". *The Quarterly Review of Biology*. **33** (1): 24–58. [doi](/source/Doi_(identifier)):[10.1086/402207](https://doi.org/10.1086%2F402207).

1. **[^](#cite_ref-27)** Cobb, N.A. (1919). ["The orders and classes of nemas"](https://www.biodiversitylibrary.org/part/58037). *Contrib. Sci. Nematol*. **8**: 213–216.

1. **[^](#cite_ref-28)** Wilson, E.O. ["Phylum Nemata"](https://web.archive.org/web/20180430120018/https://nematode.unl.edu/nemata.htm). *nematode.unl.edu*. Plant and insect parasitic nematodes. Archived from [the original](https://nematode.unl.edu/nemata.htm) on 30 April 2018. Retrieved 29 April 2018.

1. **[^](#cite_ref-29)** Kaestner, Alfred (1964). *Lehrbuch der Speziellen Zoologie* [*Invertebrate Zoology*] (in German). Vol. I. VEB Gustav Fischer Verlag; John Wiley & Sons.

1. **[^](#cite_ref-30)** Whittaker, R. H. (10 January 1969). ["New Concepts of Kingdoms of Organisms"](https://www.science.org/doi/10.1126/science.163.3863.150). *Science*. **163** (3863): 150–160. [doi](/source/Doi_(identifier)):[10.1126/science.163.3863.150](https://doi.org/10.1126%2Fscience.163.3863.150).

1. **[^](#cite_ref-31)** Nielsen, Claus (1995). *Animal Evolution: interrelationships of the living phyla* (1st ed.). Oxford University Press. [ISBN](/source/ISBN_(identifier)) [0 19 854868 0](https://en.wikipedia.org/wiki/Special:BookSources/0_19_854868_0).

1. **[^](#cite_ref-32)** Ax, Peter (2001). *Das System der Metazoa III. Ein Lehrbuch der phylogenetischen Systematik* [*Multicellular Animals Order in Nature - System Made by Man Volume III*] (in German). Vol. III. Spektrum Akademischer Verlag Gustav Fischer.

1. **[^](#cite_ref-ToL_2002_Bilateria_33-0)** ["Bilateria"](http://tolweb.org/Bilateria/2459/2002.01.01). *Tree of Life (tolweb.org)*. [Tree of Life Web Project](/source/Tree_of_Life_Web_Project). 2002. Retrieved 2 November 2008.

1. **[^](#cite_ref-34)** Howard, Richard J.; Giacomelli, Mattia; Lozano-Fernandez, Jesus; Edgecombe, Gregory D.; Fleming, James F.; Kristensen, Reinhardt M.; Ma, Xiaoya; Olesen, Jørgen; Sørensen, Martin V.; Thomsen, Philip F.; Wills, Matthew A.; Donoghue, Philip C. J.; Pisani, Davide (2022). ["The Ediacaran origin of Ecdysozoa: integrating fossil and phylogenomic data"](https://www.lyellcollection.org/doi/10.1144/jgs2021-107). *Journal of the Geological Society*. **179** (4). [doi](/source/Doi_(identifier)):[10.1144/jgs2021-107](https://doi.org/10.1144%2Fjgs2021-107). [hdl](/source/Hdl_(identifier)):[10261/295775](https://hdl.handle.net/10261%2F295775). [ISSN](/source/ISSN_(identifier)) [0016-7649](https://search.worldcat.org/issn/0016-7649).

1. ^ [***a***](#cite_ref-:2_35-0) [***b***](#cite_ref-:2_35-1) Smythe, Ashleigh B.; Holovachov, Oleksandr; Kocot, Kevin M. (13 June 2019). ["Improved phylogenomic sampling of free-living nematodes enhances resolution of higher-level nematode phylogeny"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6567515). *BMC Evolutionary Biology*. **19** (1): 121. [doi](/source/Doi_(identifier)):[10.1186/s12862-019-1444-x](https://doi.org/10.1186%2Fs12862-019-1444-x). [ISSN](/source/ISSN_(identifier)) [1471-2148](https://search.worldcat.org/issn/1471-2148). [PMC](/source/PMC_(identifier)) [6567515](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6567515). [PMID](/source/PMID_(identifier)) [31195978](https://pubmed.ncbi.nlm.nih.gov/31195978).

1. **[^](#cite_ref-36)** Laumer, Christopher E.; Fernández, Rosa; Lemer, Sarah; Combosch, David; Kocot, Kevin M.; Riesgo, Ana; Andrade, Sónia C. S.; Sterrer, Wolfgang; Sørensen, Martin V.; Giribet, Gonzalo (10 July 2019). ["Revisiting metazoan phylogeny with genomic sampling of all phyla"](https://royalsocietypublishing.org/doi/10.1098/rspb.2019.0831). *Proceedings of the Royal Society B: Biological Sciences*. **286** (1906) 20190831. [doi](/source/Doi_(identifier)):[10.1098/rspb.2019.0831](https://doi.org/10.1098%2Frspb.2019.0831). [ISSN](/source/ISSN_(identifier)) [0962-8452](https://search.worldcat.org/issn/0962-8452). [PMC](/source/PMC_(identifier)) [6650721](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6650721). [PMID](/source/PMID_(identifier)) [31288696](https://pubmed.ncbi.nlm.nih.gov/31288696).

1. **[^](#cite_ref-37)** For an up-to-date view (as of 2022), see [Phylogenomic Analysis of the Phylum Nematoda: Conflicts and Congruences With Morphology, 18S rRNA, and Mitogenomes](https://www.frontiersin.org/articles/10.3389/fevo.2021.769565/full).

1. **[^](#cite_ref-Chitwood1933_38-0)** Chitwood, B.G.; Chitwood, M.B. (1933). "The characters of a protonematode". *Journal of Parasitology*. **20**: 130.

1. **[^](#cite_ref-Chitwood1937_39-0)** Chitwood, B.G. (1937). "A revised classification of the *Nematoda*". *Papers on Helminthology published in commemoration of the 30 year Jubileum of ... K.J. Skrjabin ..*. Moscow: All-Union Lenin Academy of Agricultural Sciences. pp. 67–79.

1. **[^](#cite_ref-Chitwood1958_40-0)** Chitwood, B.G. (1958). ["The designation of official names for higher taxa of invertebrates"](https://doi.org/10.5962%2Fbhl.part.19410). *Bull Zool Nomencl*. **15**: 860–895. [doi](/source/Doi_(identifier)):[10.5962/bhl.part.19410](https://doi.org/10.5962%2Fbhl.part.19410).

1. **[^](#cite_ref-41)** Coghlan, A. (7 September 2005). ["Nematode genome evolution"](https://web.archive.org/web/20160305075651/http://www.wormbook.org/chapters/www_genomevol/genomevol.pdf) (PDF). *WormBook*: 1–15. [doi](/source/Doi_(identifier)):[10.1895/wormbook.1.15.1](https://doi.org/10.1895%2Fwormbook.1.15.1). [PMC](/source/PMC_(identifier)) [4781476](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4781476). [PMID](/source/PMID_(identifier)) [18050393](https://pubmed.ncbi.nlm.nih.gov/18050393). Archived from [the original](http://www.wormbook.org/chapters/www_genomevol/genomevol.pdf) (PDF) on 5 March 2016. Retrieved 13 January 2016.

1. **[^](#cite_ref-Blaxter_1998_42-0)** Blaxter, Mark L.; De Ley, Paul; Garey, James R.; Liu, Leo X.; Scheldeman, Patsy; et al. (March 1998). "A molecular evolutionary framework for the phylum Nematoda". *Nature*. **392** (6671): 71–75. [Bibcode](/source/Bibcode_(identifier)):[1998Natur.392...71B](https://ui.adsabs.harvard.edu/abs/1998Natur.392...71B). [doi](/source/Doi_(identifier)):[10.1038/32160](https://doi.org/10.1038%2F32160). [PMID](/source/PMID_(identifier)) [9510248](https://pubmed.ncbi.nlm.nih.gov/9510248). [S2CID](/source/S2CID_(identifier)) [4301939](https://api.semanticscholar.org/CorpusID:4301939).

1. **[^](#cite_ref-ToL:2002_Nematoda_43-0)** ["Nematoda"](http://tolweb.org/Nematoda/2472/2002.01.01). *Tree of Life Web Project*. 2002. Retrieved 2 November 2008.

1. **[^](#cite_ref-Holterman2006_44-0)** Holterman, Martijn; van der Wurff, Andre; van den Elsen, Sven; van Megen, Hanny; Bongers, Tom; et al. (2006). ["Phylum-wide analysis of SSU rDNA reveals deep phylogenetic relationships among nematodes and accelerated evolution toward crown Clades"](https://doi.org/10.1093%2Fmolbev%2Fmsl044). *Mol Biol Evol*. **23** (9): 1792–1800. [doi](/source/Doi_(identifier)):[10.1093/molbev/msl044](https://doi.org/10.1093%2Fmolbev%2Fmsl044). [PMID](/source/PMID_(identifier)) [16790472](https://pubmed.ncbi.nlm.nih.gov/16790472).

1. ^ [***a***](#cite_ref-:1_45-0) [***b***](#cite_ref-:1_45-1) Khadka, Bijendra; Chatterjee, Tonuka; Gupta, Bhagwati P.; Gupta, Radhey S. (24 September 2019). ["Genomic Analyses Identify Novel Molecular Signatures Specific for the *Caenorhabditis* and other Nematode Taxa Providing Novel Means for Genetic and Biochemical Studies"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826867). *Genes*. **10** (10): 739. [doi](/source/Doi_(identifier)):[10.3390/genes10100739](https://doi.org/10.3390%2Fgenes10100739). [PMC](/source/PMC_(identifier)) [6826867](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826867). [PMID](/source/PMID_(identifier)) [31554175](https://pubmed.ncbi.nlm.nih.gov/31554175).

1. **[^](#cite_ref-Liu2013_46-0)** Liu, Guo-Hua; Shao, Renfu; Li, Jia-Yuan; Zhou, Dong-Hui; Li, Hu; Zhu, Xing-Quan (2013). ["The complete mitochondrial genomes of three parasitic nematodes of birds: a unique gene order and insights into nematode phylogeny"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3693896). *BMC Genomics*. **14** (1): 414. [doi](/source/Doi_(identifier)):[10.1186/1471-2164-14-414](https://doi.org/10.1186%2F1471-2164-14-414). [PMC](/source/PMC_(identifier)) [3693896](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3693896). [PMID](/source/PMID_(identifier)) [23800363](https://pubmed.ncbi.nlm.nih.gov/23800363).

1. **[^](#cite_ref-47)** Hodda, M. (2022). ["Phylum Nematoda: a classification, catalogue and index of valid genera, with a census of valid species"](https://doi.org/10.11646%2Fzootaxa.5114.1.1). *Zootaxa*. **5114** (1): 1–289. [Bibcode](/source/Bibcode_(identifier)):[2022Zoot.5114....1H](https://ui.adsabs.harvard.edu/abs/2022Zoot.5114....1H). [doi](/source/Doi_(identifier)):[10.11646/zootaxa.5114.1.1](https://doi.org/10.11646%2Fzootaxa.5114.1.1). [PMID](/source/PMID_(identifier)) [35391386](https://pubmed.ncbi.nlm.nih.gov/35391386).

1. **[^](#cite_ref-48)** Macêdo do Carmo, Gustavo; Garcia, Renato Araujo; Vieira, Fabiano Matos; de Souza Lima, Sueli; Ismael de Araújo-Júnior, Hermínio; Pinheiro, Ralph Maturano (May 2023). ["Paleoparasitological study of avian trace fossils from the Tremembé Formation (Oligocene of the Taubaté Basin), São Paulo, Brazil"](https://linkinghub.elsevier.com/retrieve/pii/S089598112300130X). *[Journal of South American Earth Sciences](/source/Journal_of_South_American_Earth_Sciences)*. **125** 104319. [Bibcode](/source/Bibcode_(identifier)):[2023JSAES.12504319M](https://ui.adsabs.harvard.edu/abs/2023JSAES.12504319M). [doi](/source/Doi_(identifier)):[10.1016/j.jsames.2023.104319](https://doi.org/10.1016%2Fj.jsames.2023.104319). Retrieved 12 April 2024 – via Elsevier Science Direct.

1. ^ [***a***](#cite_ref-Ruppert7th_49-0) [***b***](#cite_ref-Ruppert7th_49-1) Ruppert, Edward E.; Barnes, Robert D.; Fox, Richard S. (2019). *Invertebrate zoology: a functional evolutionary approach* (Seventh, Seventh Indian Reprint ed.). Delhi, India: Cengage Learning. pp. 757–770. [ISBN](/source/ISBN_(identifier)) [978-81-315-0104-7](https://en.wikipedia.org/wiki/Special:BookSources/978-81-315-0104-7).

1. **[^](#cite_ref-Weischer_2000_50-0)** Weischer, B.; Brown, D.J. (2000). *An Introduction to Nematodes: General Nematology*. Sofia, Bulgaria: Pensoft. pp. 75–76. [ISBN](/source/ISBN_(identifier)) [978-954-642-087-9](https://en.wikipedia.org/wiki/Special:BookSources/978-954-642-087-9).

1. ^ [***a***](#cite_ref-Barnes_1980_51-0) [***b***](#cite_ref-Barnes_1980_51-1) [***c***](#cite_ref-Barnes_1980_51-2) [***d***](#cite_ref-Barnes_1980_51-3) [***e***](#cite_ref-Barnes_1980_51-4) [***f***](#cite_ref-Barnes_1980_51-5) [***g***](#cite_ref-Barnes_1980_51-6) [***h***](#cite_ref-Barnes_1980_51-7) [***i***](#cite_ref-Barnes_1980_51-8) [***j***](#cite_ref-Barnes_1980_51-9) [***k***](#cite_ref-Barnes_1980_51-10) [***l***](#cite_ref-Barnes_1980_51-11) Barnes, R.G. (1980). *Invertebrate zoology*. Philadelphia: Sanders College. [ISBN](/source/ISBN_(identifier)) [978-0-03-056747-6](https://en.wikipedia.org/wiki/Special:BookSources/978-0-03-056747-6).

1. **[^](#cite_ref-52)** Huang, Yong; Guo, Yuqing (27 November 2021). [*Free-living Marine Nematodes from the East China Sea*](https://books.google.com/books?id=qXRREAAAQBAJ&dq=nematodes+nerve+ring+pharynx+ventral+dorsal+sublateral+cords&pg=PA10). Springer Nature. [ISBN](/source/ISBN_(identifier)) [978-981-16-3836-7](https://en.wikipedia.org/wiki/Special:BookSources/978-981-16-3836-7) – via Google Books.

1. **[^](#cite_ref-53)** ["The sensory cilia of *Caenorhabditis elegans*"](http://www.wormbook.org/chapters/www_ciliumbiogenesis.2/ciliumbiogenesis.html). *www.wormbook.org*.

1. **[^](#cite_ref-54)** Kavlie, RG; Kernan, MJ; Eberl, DF (May 2010). ["Hearing in Drosophila requires TilB, a conserved protein associated with ciliary motility"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870953). *Genetics*. **185** (1): 177–88. [doi](/source/Doi_(identifier)):[10.1534/genetics.110.114009](https://doi.org/10.1534%2Fgenetics.110.114009). [PMC](/source/PMC_(identifier)) [2870953](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870953). [PMID](/source/PMID_(identifier)) [20215474](https://pubmed.ncbi.nlm.nih.gov/20215474).

1. **[^](#cite_ref-55)** Lalošević, V.; Lalošević, D.; Capo, I.; Simin, V.; Galfi, A.; Traversa, D. (2013). ["High infection rate of zoonotic *Eucoleus aerophilus* infection in foxes from Serbia"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3718516). *Parasite*. **20**: 3. [doi](/source/Doi_(identifier)):[10.1051/parasite/2012003](https://doi.org/10.1051%2Fparasite%2F2012003). [PMC](/source/PMC_(identifier)) [3718516](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3718516). [PMID](/source/PMID_(identifier)) [23340229](https://pubmed.ncbi.nlm.nih.gov/23340229).

1. **[^](#cite_ref-56)** Nelson, G A; Roberts, T M; Ward, S (1 January 1982). ["Caenorhabditis elegans spermatozoan locomotion: amoeboid movement with almost no actin"](https://rupress.org/jcb/article/92/1/121/19566/Caenorhabditis-elegans-spermatozoan-locomotion). *The Journal of Cell Biology*. **92** (1): 121–131. [doi](/source/Doi_(identifier)):[10.1083/jcb.92.1.121](https://doi.org/10.1083%2Fjcb.92.1.121). [PMC](/source/PMC_(identifier)) [2111997](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111997). [PMID](/source/PMID_(identifier)) [7199049](https://pubmed.ncbi.nlm.nih.gov/7199049).

1. **[^](#cite_ref-Bond&Huffman2023_57-0)** Bond, Alan Thomas; Huffman, David George (2023). ["Nematode eggshells: A new anatomical and terminological framework, with a critical review of relevant literature and suggested guidelines for the interpretation and reporting of eggshell imagery"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10016204). *Parasite*. **30**: 6. [doi](/source/Doi_(identifier)):[10.1051/parasite/2023007](https://doi.org/10.1051%2Fparasite%2F2023007). [PMC](/source/PMC_(identifier)) [10016204](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10016204). [PMID](/source/PMID_(identifier)) [36920277](https://pubmed.ncbi.nlm.nih.gov/36920277).

1. **[^](#cite_ref-Bell_1982_58-0)** Bell, G. (1982). *The masterpiece of nature: the evolution and genetics of sexuality*. Berkeley: University of California Press. [ISBN](/source/ISBN_(identifier)) [978-0-520-04583-5](https://en.wikipedia.org/wiki/Special:BookSources/978-0-520-04583-5).

1. ^ [***a***](#cite_ref-Johnigk_Ehlers_1999_59-0) [***b***](#cite_ref-Johnigk_Ehlers_1999_59-1) Johnigk, Stefan-Andreas; Ehlers, Ralf-Udo (1999). "*Endotokia matricida* in hermaphrodites of *Heterorhabditis* spp. and the effect of the food supply". *Nematology*. **1** (7–8): 717–726. [Bibcode](/source/Bibcode_(identifier)):[1999Nemat...1..717J](https://ui.adsabs.harvard.edu/abs/1999Nemat...1..717J). [doi](/source/Doi_(identifier)):[10.1163/156854199508748](https://doi.org/10.1163%2F156854199508748). [ISSN](/source/ISSN_(identifier)) [1388-5545](https://search.worldcat.org/issn/1388-5545). [S2CID](/source/S2CID_(identifier)) [85279418](https://api.semanticscholar.org/CorpusID:85279418).

1. **[^](#cite_ref-Haag_et_al_2018_60-0)** Haag, Eric S.; Helder, Johannes; Mooijman, Paul J. W.; Yin, Da; Hu, Shuang (2018). ["The evolution of uniparental reproduction in Rhabditina nematodes: Phylogenetic patterns, developmental causes, and surprising consequences"](https://link.springer.com/chapter/10.1007/978-3-319-94139-4_4). In Leonard, J.L. (ed.). *Transitions Between Sexual Systems*. Springer. pp. 99–122. [doi](/source/Doi_(identifier)):[10.1007/978-3-319-94139-4_4](https://doi.org/10.1007%2F978-3-319-94139-4_4). [ISBN](/source/ISBN_(identifier)) [978-3-319-94137-0](https://en.wikipedia.org/wiki/Special:BookSources/978-3-319-94137-0).

1. ^ [***a***](#cite_ref-Hyun2008_61-0) [***b***](#cite_ref-Hyun2008_61-1) Hyun, Moonjung; Lee, Jihyun; Lee, Kyungjin; May, Alfred; Bohr, Vilhelm A.; Ahn, Byungchan (March 2008). ["Longevity and resistance to stress correlate with DNA repair capacity in *Caenorhabditis elegans*"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2275101). *Nucleic Acids Res*. **36** (4): 1380–9. [doi](/source/Doi_(identifier)):[10.1093/nar/gkm1161](https://doi.org/10.1093%2Fnar%2Fgkm1161). [PMC](/source/PMC_(identifier)) [2275101](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2275101). [PMID](/source/PMID_(identifier)) [18203746](https://pubmed.ncbi.nlm.nih.gov/18203746).

1. **[^](#cite_ref-62)** Raices, Marilina; Bowman, Richard; Smolikove, Sarit; Yanowitz, Judith L. (2021). ["Aging Negatively Impacts DNA Repair and Bivalent Formation in the *C. elegans* Germ Line"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8371636). *Front Cell Dev Biol*. **9** 695333. [doi](/source/Doi_(identifier)):[10.3389/fcell.2021.695333](https://doi.org/10.3389%2Ffcell.2021.695333). [PMC](/source/PMC_(identifier)) [8371636](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8371636). [PMID](/source/PMID_(identifier)) [34422819](https://pubmed.ncbi.nlm.nih.gov/34422819).

1. **[^](#cite_ref-63)** c. Elegans Sequencing, Consortium (1998). "Genome sequence of the nematode C. Elegans: A platform for investigating biology". *Science*. **282** (5396): 2012–2018. [doi](/source/Doi_(identifier)):[10.1126/science.282.5396.2012](https://doi.org/10.1126%2Fscience.282.5396.2012). [PMID](/source/PMID_(identifier)) [9851916](https://pubmed.ncbi.nlm.nih.gov/9851916).

1. **[^](#cite_ref-64)** ["Neuronal Wiring"](https://www.wormatlas.org/neuronalwiring.html).

1. **[^](#cite_ref-pmid18279076_65-0)** Yanoviak, S. P.; Kaspari, M.; Dudley, R.; Poinar, G. (April 2008). "Parasite-induced fruit mimicry in a tropical canopy ant". *Am. Nat*. **171** (4): 536–44. [Bibcode](/source/Bibcode_(identifier)):[2008ANat..171..536Y](https://ui.adsabs.harvard.edu/abs/2008ANat..171..536Y). [doi](/source/Doi_(identifier)):[10.1086/528968](https://doi.org/10.1086%2F528968). [PMID](/source/PMID_(identifier)) [18279076](https://pubmed.ncbi.nlm.nih.gov/18279076). [S2CID](/source/S2CID_(identifier)) [23857167](https://api.semanticscholar.org/CorpusID:23857167).

1. **[^](#cite_ref-66)** Batra, Suzanne W. T. (1 October 1965). "Organisms associated with *Lasioglossum zephyrum* (Hymenoptera: Halictidae)". *Journal of the Kansas Entomological Society*. **38** (4): 367–389. [JSTOR](/source/JSTOR_(identifier)) [25083474](https://www.jstor.org/stable/25083474).

1. **[^](#cite_ref-67)** Purcell, Mary; Johnson, Marshall W.; Lebeck, Lynn M.; Hara, Arnold H. (1992). "Biological Control of Helicoverpa zea (Lepidoptera: Noctuidae) with Steinernema carpocapsae (Rhabditida: Steinernematidae) in Corn Used as a Trap Crop". *Environmental Entomology*. **21** (6): 1441–7. [doi](/source/Doi_(identifier)):[10.1093/ee/21.6.1441](https://doi.org/10.1093%2Fee%2F21.6.1441).

1. **[^](#cite_ref-68)** Wilson, M. J.; Glen, D. M.; George, S. K. (January 1993). "The rhabditid nematode Phasmarhabditis hermaphrodita as a potential biological control agent for slugs". *Biocontrol Science and Technology*. **3** (4): 503–511. [Bibcode](/source/Bibcode_(identifier)):[1993BioST...3..503W](https://ui.adsabs.harvard.edu/abs/1993BioST...3..503W). [doi](/source/Doi_(identifier)):[10.1080/09583159309355306](https://doi.org/10.1080%2F09583159309355306).

1. **[^](#cite_ref-69)** Rajamani, Meenatchi; Negi, Aditi (2021). "Biopesticides for Pest Management". *Sustainable Bioeconomy*. pp. 239–266. [doi](/source/Doi_(identifier)):[10.1007/978-981-15-7321-7_11](https://doi.org/10.1007%2F978-981-15-7321-7_11). [ISBN](/source/ISBN_(identifier)) [978-981-15-7320-0](https://en.wikipedia.org/wiki/Special:BookSources/978-981-15-7320-0). [S2CID](/source/S2CID_(identifier)) [228845133](https://api.semanticscholar.org/CorpusID:228845133).

1. **[^](#cite_ref-70)** Ehlers, R.-U.; Hokkanen, H. M. T. (September 1996). "Insect Biocontrol with Non-endemic Entomopathogenic Nematodes (Steinernema and Heterorhabditis spp.): Conclusions and Recommendations of a Combined OECD and COST Workshop on Scientific and Regulatory Policy Issues". *Biocontrol Science and Technology*. **6** (3): 295–302. [Bibcode](/source/Bibcode_(identifier)):[1996BioST...6..295E](https://ui.adsabs.harvard.edu/abs/1996BioST...6..295E). [doi](/source/Doi_(identifier)):[10.1080/09583159631280](https://doi.org/10.1080%2F09583159631280).

1. **[^](#cite_ref-Smiley-et-al-2017_71-0)** Smiley, Richard W.; Dababat, Abdelfattah A.; Iqbal, Sadia; Jones, Michael G. K.; Maafi, Zahra Tanha; Peng, Deliang; Subbotin, Sergei A.; Waeyenberge, Lieven (2017). ["Cereal Cyst Nematodes: A Complex and Destructive Group of *Heterodera* Species"](https://doi.org/10.1094%2Fpdis-03-17-0355-fe). *[Plant Disease](/source/Plant_Disease_(journal))*. **101** (10). [American Phytopathological Society](/source/American_Phytopathological_Society): 1692–1720. [Bibcode](/source/Bibcode_(identifier)):[2017PlDis.101.1692S](https://ui.adsabs.harvard.edu/abs/2017PlDis.101.1692S). [doi](/source/Doi_(identifier)):[10.1094/pdis-03-17-0355-fe](https://doi.org/10.1094%2Fpdis-03-17-0355-fe). [ISSN](/source/ISSN_(identifier)) [0191-2917](https://search.worldcat.org/issn/0191-2917). [PMID](/source/PMID_(identifier)) [30676930](https://pubmed.ncbi.nlm.nih.gov/30676930).

1. **[^](#cite_ref-72)** Gibbs, J.N.; Webber, J.F. (2004), ["PATHOLOGY | Insect Associated Tree Diseases"](https://linkinghub.elsevier.com/retrieve/pii/B0121451607000703), *Encyclopedia of Forest Sciences*, Elsevier, pp. 802–8, [doi](/source/Doi_(identifier)):[10.1016/b0-12-145160-7/00070-3](https://doi.org/10.1016%2Fb0-12-145160-7%2F00070-3), [ISBN](/source/ISBN_(identifier)) [978-0-12-145160-8](https://en.wikipedia.org/wiki/Special:BookSources/978-0-12-145160-8), retrieved 21 March 2023

1. **[^](#cite_ref-73)** Kloosterman, Stephen (April 2022). "Small Soldiers". *Green House Product News*. Vol. 32, no. 4. pp. 26–29.

1. **[^](#cite_ref-74)** Krueger, R.; Dover, K. E.; McSorley, R.; Wang, K-H. ["ENY-056/NG045: Marigolds (Tagetes spp.) for Nematode Management"](https://edis.ifas.ufl.edu/publication/NG045). *[Institute of Food and Agricultural Sciences](/source/Institute_of_Food_and_Agricultural_Sciences)*. Retrieved 20 November 2023.

1. **[^](#cite_ref-75)** Pires, David; Vicente, Cláudia S. L.; Menéndez, Esther; Faria, Jorge M. S.; Rusinque, Leidy; Camacho, Maria J.; Inácio, Maria L. (October 2022). ["The Fight against Plant-Parasitic Nematodes: Current Status of Bacterial and Fungal Biocontrol Agents"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9566127). *Pathogens*. **11** (10): 1178. [doi](/source/Doi_(identifier)):[10.3390/pathogens11101178](https://doi.org/10.3390%2Fpathogens11101178). [hdl](/source/Hdl_(identifier)):[10174/32705](https://hdl.handle.net/10174%2F32705). [PMC](/source/PMC_(identifier)) [9566127](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9566127). [PMID](/source/PMID_(identifier)) [36231510](https://pubmed.ncbi.nlm.nih.gov/36231510).

1. **[^](#cite_ref-US-2008/072494_76-0)** [US application 2008072494](https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US2008072494), Stoner, R.J.; Linden, J.C., "Micronutrient elicitor for treating nematodes in field crops", published 27 March 2008

1. **[^](#cite_ref-CSIRO_77-0)** Loothfar, R.; Tony, S. (22 March 2005). ["Suppression of root knot nematode (*Meloidogyne javanica*) after incorporation of Indian mustard cv. Nemfix as green manure and seed meal in vineyards"](http://www.publish.csiro.au/paper/AP04081). *[Australasian Plant Pathology](/source/Australasian_Plant_Pathology)*. **34** (1): 77–83. [Bibcode](/source/Bibcode_(identifier)):[2005AuPP...34...77R](https://ui.adsabs.harvard.edu/abs/2005AuPP...34...77R). [doi](/source/Doi_(identifier)):[10.1071/AP04081](https://doi.org/10.1071%2FAP04081). [S2CID](/source/S2CID_(identifier)) [24299033](https://api.semanticscholar.org/CorpusID:24299033). Retrieved 14 June 2010.

1. **[^](#cite_ref-Patiño_78-0)** Patiño, JA; Olivera, MJ (15 June 2019). ["Gastro-allergic anisakiasis: The first case reported in Colombia and a literature review"](https://doi.org/10.7705%2Fbiomedica.v39i2.3936). *Biomedica: Revista del Instituto Nacional de Salud*. **39** (2): 241–246. [doi](/source/Doi_(identifier)):[10.7705/biomedica.v39i2.3936](https://doi.org/10.7705%2Fbiomedica.v39i2.3936). [PMID](/source/PMID_(identifier)) [31529811](https://pubmed.ncbi.nlm.nih.gov/31529811).

1. **[^](#cite_ref-79)** Stepek, Gillian; Buttle, David J.; Duce, Ian R.; Behnke, Jerzy M. (October 2006). ["Human gastrointestinal nematode infections: are new control methods required?"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517378). *International Journal of Experimental Pathology*. **87** (5): 325–341. [doi](/source/Doi_(identifier)):[10.1111/j.1365-2613.2006.00495.x](https://doi.org/10.1111%2Fj.1365-2613.2006.00495.x). [PMC](/source/PMC_(identifier)) [2517378](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517378). [PMID](/source/PMID_(identifier)) [16965561](https://pubmed.ncbi.nlm.nih.gov/16965561).

1. **[^](#cite_ref-80)** Warshafsky, Zoemma T.; Tuckey, Troy D.; Vogelbein, Wolfgang K.; Latour, Robert J.; Wargo, Andrew R. (2019). ["Temporal, spatial, and biological variation of nematode epidemiology in American eels"](https://scholarworks.wm.edu/vimsarticles/1780). *Canadian Journal of Fisheries and Aquatic Sciences*. **76** (10): 1808–1818. [Bibcode](/source/Bibcode_(identifier)):[2019CJFAS..76.1808W](https://ui.adsabs.harvard.edu/abs/2019CJFAS..76.1808W). [doi](/source/Doi_(identifier)):[10.1139/cjfas-2018-0136](https://doi.org/10.1139%2Fcjfas-2018-0136). [hdl](/source/Hdl_(identifier)):[1807/95295](https://hdl.handle.net/1807%2F95295).

1. **[^](#cite_ref-81)** Jithendran, K.P.; Bhat, T.K. (1999). "Epidemiology of Parasitoses in Dairy Animals in the North West Humid Himalayan Region of India with Particular Reference to Gastrointestinal Nematodes". *Tropical Animal Health and Production*. **31** (4): 205–214. [doi](/source/Doi_(identifier)):[10.1023/A:1005263009921](https://doi.org/10.1023%2FA%3A1005263009921). [PMID](/source/PMID_(identifier)) [10504100](https://pubmed.ncbi.nlm.nih.gov/10504100).

1. **[^](#cite_ref-82)** Morgan, E.R.; van Dijk, J. (September 2012). "Climate and the epidemiology of gastrointestinal nematode infections of sheep in Europe". *Vet Parasitol*. **189** (1): 8–14. [doi](/source/Doi_(identifier)):[10.1016/j.vetpar.2012.03.028](https://doi.org/10.1016%2Fj.vetpar.2012.03.028). [PMID](/source/PMID_(identifier)) [22494941](https://pubmed.ncbi.nlm.nih.gov/22494941).

1. **[^](#cite_ref-brady_83-0)** Brady, Nyle C.; Weil, Ray R. (2009). *Elements of the Nature and Properties of Soils* (3rd ed.). Prentice Hall. [ISBN](/source/ISBN_(identifier)) [978-0-13-501433-2](https://en.wikipedia.org/wiki/Special:BookSources/978-0-13-501433-2). [OCLC](/source/OCLC_(identifier)) [1015309711](https://search.worldcat.org/oclc/1015309711).

1. **[^](#cite_ref-84)** Jasmer, Douglas P.; Goverse, Aska; Smant, Geert (2003). ["Parasitic nematode interactions with mammals and plants"](http://www.annualreviews.org/doi/full/10.1146/annurev.phyto.41.052102.104023). *Annual Review of Phytopathology*. **41** (1): 245–270. [Bibcode](/source/Bibcode_(identifier)):[2003AnRvP..41..245J](https://ui.adsabs.harvard.edu/abs/2003AnRvP..41..245J). [doi](/source/Doi_(identifier)):[10.1146/annurev.phyto.41.052102.104023](https://doi.org/10.1146%2Fannurev.phyto.41.052102.104023). [PMID](/source/PMID_(identifier)) [14527330](https://pubmed.ncbi.nlm.nih.gov/14527330).

1. **[^](#cite_ref-85)** Nosowitz, Fan (8 February 2021). ["How California Crops Fought Off a Pest Without Using Pesticide"](https://modernfarmer.com/2021/02/how-california-crops-fought-off-a-pest-without-using-pesticide/). *Modern Farmer*. Retrieved 15 February 2021.

1. **[^](#cite_ref-Pramer_1964_86-0)** Pramer, C. (1964). "Nematode-trapping fungi". *Science*. **144** (3617): 382–388. [Bibcode](/source/Bibcode_(identifier)):[1964Sci...144..382P](https://ui.adsabs.harvard.edu/abs/1964Sci...144..382P). [doi](/source/Doi_(identifier)):[10.1126/science.144.3617.382](https://doi.org/10.1126%2Fscience.144.3617.382). [PMID](/source/PMID_(identifier)) [14169325](https://pubmed.ncbi.nlm.nih.gov/14169325).

1. **[^](#cite_ref-Hauser_1985_87-0)** Hauser, J.T. (December 1985). ["Nematode-trapping fungi"](http://www.carnivorousplants.org/cpn/articles/CPNv14n1p8_11.pdf) (PDF). *Carnivorous Plant Newsletter*. **14** (1): 8–11. [doi](/source/Doi_(identifier)):[10.55360/cpn141.jh945](https://doi.org/10.55360%2Fcpn141.jh945).

1. **[^](#cite_ref-Ahrén_1998_88-0)** Ahrén, D.; Ursing, B.M.; Tunlid, A. (1998). "Phylogeny of nematode-trapping fungi based on 18S rDNA sequences". *FEMS Microbiology Letters*. **158** (2): 179–184. [doi](/source/Doi_(identifier)):[10.1111/j.1574-6968.1998.tb12817.x](https://doi.org/10.1111%2Fj.1574-6968.1998.tb12817.x). [PMID](/source/PMID_(identifier)) [9465391](https://pubmed.ncbi.nlm.nih.gov/9465391).

1. **[^](#cite_ref-Lee2023_89-0)** Lee, CH; Lee, YY; Chang, YC; Pon, WL; Lee, SP; Wali, N; Nakazawa, T; Honda, Y; Shie, JJ; Hsueh, YP (18 January 2023). ["A carnivorous mushroom paralyzes and kills nematodes via a volatile ketone"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9848476). *Science Advances*. **9** (3) eade4809. [Bibcode](/source/Bibcode_(identifier)):[2023SciA....9E4809L](https://ui.adsabs.harvard.edu/abs/2023SciA....9E4809L). [doi](/source/Doi_(identifier)):[10.1126/sciadv.ade4809](https://doi.org/10.1126%2Fsciadv.ade4809). [PMC](/source/PMC_(identifier)) [9848476](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9848476). [PMID](/source/PMID_(identifier)) [36652525](https://pubmed.ncbi.nlm.nih.gov/36652525).

1. **[^](#cite_ref-90)** ["Columbia Survivors"](https://web.archive.org/web/20160304201612/http://www.astrobio.net/topic/origins/extreme-life/columbia-survivors/). *Astrobiology Magazine*. 1 January 2006. Archived from the original on 4 March 2016. Retrieved 12 January 2016.

1. **[^](#cite_ref-91)** Szewczyk, Nathaniel J.; Mancinelli, Rocco L.; McLamb, William; Reed, David; Blumberg, Baruch S.; Conley, Catharine A. (December 2005). "*Caenorhabditis elegans* Survives Atmospheric Breakup of STS–107, Space Shuttle Columbia". *Astrobiology*. **5** (6): 690–705. [Bibcode](/source/Bibcode_(identifier)):[2005AsBio...5..690S](https://ui.adsabs.harvard.edu/abs/2005AsBio...5..690S). [doi](/source/Doi_(identifier)):[10.1089/ast.2005.5.690](https://doi.org/10.1089%2Fast.2005.5.690). [PMID](/source/PMID_(identifier)) [16379525](https://pubmed.ncbi.nlm.nih.gov/16379525).

1. **[^](#cite_ref-92)** Raymond, Mélianie R.; Wharton, David A. (February 2013). ["The ability of the Antarctic nematode *Panagrolaimus davidi* to survive intracellular freezing is dependent upon nutritional status"](http://link.springer.com/10.1007/s00360-012-0697-0). *Journal of Comparative Physiology B*. **183** (2): 181–8. [doi](/source/Doi_(identifier)):[10.1007/s00360-012-0697-0](https://doi.org/10.1007%2Fs00360-012-0697-0). [PMID](/source/PMID_(identifier)) [22836298](https://pubmed.ncbi.nlm.nih.gov/22836298). [S2CID](/source/S2CID_(identifier)) [17294698](https://api.semanticscholar.org/CorpusID:17294698).

1. **[^](#cite_ref-93)** Shatilovich, Anastasia; Gade, Vamshidhar R. (27 July 2023). ["A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with *C. elegans* dauer larva"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10374039). *PLOS Genetics*. **19** (7) e1010798. [doi](/source/Doi_(identifier)):[10.1371/journal.pgen.1010798](https://doi.org/10.1371%2Fjournal.pgen.1010798). [PMC](/source/PMC_(identifier)) [10374039](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10374039). [PMID](/source/PMID_(identifier)) [37498820](https://pubmed.ncbi.nlm.nih.gov/37498820).

## External links

Wikimedia Commons has media related to [Nematoda](https://commons.wikimedia.org/wiki/Category:Nematoda).

- [Harper Adams University College Nematology Research](https://web.archive.org/web/20101230000456/http://www.harper-adams.ac.uk/groups/crops/nematology/)

- [Nematodes/roundworms of man](https://wayback.archive-it.org/all/20110721030344/http://knol.google.com/k/nematodes-roundworms-of-man#view)

- [Introduction to the Nematoda](http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html)

- [European Society of Nematologists](http://www.esn-online.org/)

- [http://webarchive.loc.gov/all/20020914155908/http://www.nematodes.org/](http://webarchive.loc.gov/all/20020914155908/http://www.nematodes.org/)

- [NeMys World free-living Marine Nematodes database](https://web.archive.org/web/20061027152335/http://intramar.ugent.be/nemys/start.asp?group=2)

- [Nematode Virtual Library](http://faculty.ucr.edu/%7Epdeley/lab/taxonomy.html)

- [Society of Nematologists](http://nematologists.org/)

- [Australasian Association of Nematologists](http://nematologists.org.au/) [Archived](https://web.archive.org/web/20150226031051/http://nematologists.org.au/) 26 February 2015 at the [Wayback Machine](/source/Wayback_Machine)

- [Phylum Nematoda – nematodes](http://entnemdept.ufl.edu/creatures/main/search_higher_nematodes.htm) on the [UF](/source/University_of_Florida)

- [Featured Creatures Web site](https://entnemdept.ufl.edu/creatures/)—University of Florida Institute of Food and Agricultural Sciences (IFAS)

v t e Extant animal phyla Domain Archaea Bacteria Eukaryota (major groups Metamonada Discoba Diaphoretickes Hacrobia Cryptista Rhizaria Alveolata Stramenopiles Plants Amorphea Amoebozoa Opisthokonta Animalia Fungi Mesomycetozoea) Animalia Porifera (sponges) Ctenophora (comb jellies) ParaHoxozoa (Planulozoa) Placozoa (Trichoplax and relatives) Cnidaria (jellyfish and relatives) Bilateria (Triploblasts) (see below↓) The phylogeny of the animal root is disputed; see also Eumetazoa Benthozoa Bilateria Bilateria Xenacoelomorpha (acoels and relatives) Chordata (vertebrates and relatives) Ambulacraria Echinodermata (starfish and relatives) Hemichordata (acorn worms and relatives) Protostomia Ecdysozoa Scalidophora Kinorhyncha (mud dragons) Priapulida (penis worms) Loricifera (corset animals) Cryptovermes Nematoida Nematoda (roundworms) Nematomorpha (horsehair worms) Panarthropoda Onychophora (velvet worms) Arthropoda (insects and relatives) Tardigrada (waterbears) Spiralia Gnathifera Chaetognatha (arrow worms) Gnathostomulida (jaw worms) M+R Micrognathozoa (Limnognathia) Rotifera (wheel animals inc. acanthocephalans) Platytrochozoa C+E Cycliophora (Symbion) Entoprocta or Kamptozoa Rouphozoa Platyhelminthes (flatworms) Gastrotricha (hairybacks) Mesozoa Orthonectida Dicyemida or Rhombozoa ?Monoblastozoa (Salinella) Lophotrochozoa Annelida (earth worms and relatives) Mollusca (snails and relatives) Nemertea (ribbon worms) Lophophorata Brachiopoda (lamp shells) B+P Bryozoa or Ectoprocta (moss animals) Phoronida (horseshoe worms) The phylogeny of Bilateria is disputed; see also Nephrozoa Deuterostomia Xenambulacraria Centroneuralia Major groups within phyla Sponges Demosponges Glass sponges Calcareous sponges Cnidarians Anthozoans inc. corals Medusozoans inc. jellyfish Myxozoans Chordates Lancelets Tunicates Vertebrates Echinoderms Sea lilies Asterozoans inc. starfish Echinozoans inc. sea urchins Hemichordates Acorn worms Pterobranchs Nematodes Chromadorea Enoplea Secernentea Arthropods Chelicerates inc. arachnids Myriapods Pancrustaceans inc. hexapods Rotifera Bdelloidea Monogononta Seisonidae Acanthocephala Platyhelminths Turbellaria Trematoda Monogenea Cestoda Ectoproctans Phylactolaemata Stenolaemata Gymnolaemata Annelids Polychaetes Clitellata Sipuncula Molluscs Gastropods Cephalopods Bivalves Chitons Tusk shells Phyla with ≥1000 extant species bolded Potentially dubious phyla †

v t e Extant life phyla/divisions by domain Bacteria Abditibacteriota Acidobacteriota Actinomycetota Aquificota Armatimonadota Atribacterota Bacillota Bacteroidota Balneolota Caldisericota Calditrichota Chlamydiota Chlorobiota Chloroflexota Chrysiogenota Coprothermobacterota Cyanobacteriota Deferribacterota Deinococcota Dictyoglomerota Elusimicrobiota Fibrobacterota Fidelibacterota Fusobacteriota Gemmatimonadota Kiritimatiellota Lentisphaerota Minisyncoccota Mycoplasmatota Nitrospinota Nitrospirota Planctomycetota Pseudomonadota Rhodothermota Spirochaetota Synergistota Thermodesulfobacteriota Thermomicrobiota Thermotogota Verrucomicrobiota Vulcanimicrobiota "Acetithermota" "Aerophobota" "Auribacterota" "Babelota" "Binatota" "Bipolaricaulota" "Caldipriscota" "Calescibacteriota" "Canglongiota" "Cloacimonadota" "Cosmopoliota" "Cryosericota" "Deferrimicrobiota" "Dormiibacterota" "Effluvivivacota" "Electryoneota" "Elulimicrobiota" "Fermentibacterota" "Fervidibacterota" "Goldiibacteriota" "Heilongiota" "Hinthialibacterota" "Hydrogenedentota" "Hydrothermota" "Kapaibacteriota" "Krumholzibacteriota" "Kryptoniota" "Latescibacterota" "Lernaellota" "Lithacetigenota" "Macinerneyibacteriota" "Margulisiibacteriota" "Methylomirabilota" "Moduliflexota" "Muiribacteriota" "Nitrosediminicolota" "Omnitrophota" "Parcunitrobacterota" "Peregrinibacteriota" "Qinglongiota" "Rifleibacteriota" "Ryujiniota" "Spongiamicota" "Sumerlaeota" "Sysuimicrobiota" "Tangaroaeota" "Tectimicrobiota" "Tianyaibacteriota" "Wirthibacterota" "Zhuqueibacterota" "Zhurongbacterota" Archaea Methanobacteriota Microcaldota Nanobdellota Promethearchaeota Thermoproteota "Aenigmatarchaeota" "Altarchaeota" "Augarchaeota" "Geoarchaeota" "Hadarchaeota" "Hadesarchaeota" "Huberarchaeota" "Hydrothermarchaeota" "Iainarchaeota" "Micrarchaeota" "Nanohalarchaeota" "Nezhaarchaeota" "Parvarchaeota" "Poseidoniota" "Undinarchaeota" Eukaryote Protist Acavomonidia Amoebozoa Anaeramoebae Apicomplexa Bigyra Bigyromonadea Caelestes Cercozoa Chlorophyta Chromerida Ciliophora Colponemidia Cryptista Dinoflagellata Euglenozoa Foraminifera Fornicata Glaucophyta Haptophyta Hemimastigophora Malawimonada Nebulidia Nibbleridia Ochrophyta Preaxostyla Heterolobosea Hyphochytriomycota Oomycota Parabasalia Perkinsozoa Picozoa Radiolaria Rhodelphidia Rhodophyta Telonemia Fungi Chytridiomycota Blastocladiomycota Neocallimastigomycota Glomeromycota Zygomycota Ascomycota Basidiomycota Land plant Bryophyta Marchantiophyta Anthocerotophyta Lycopodiophyta Pteridophyta Cycadophyta Ginkgophyta Pinophyta Gnetophyta Animal Porifera Ctenophora Placozoa Cnidaria Xenacoelomorpha Chordata Hemichordata Echinodermata Chaetognatha Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Platyhelminthes Gastrotricha Orthonectida Dicyemida Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Nemertea Phoronida Bryozoa Entoprocta Brachiopoda Mollusca Annelida Incertae sedis Parakaryon Relate: Extraterrestrial life

v t e Parasitic disease caused by helminthiases Flatworm/ platyhelminth infection Fluke/trematode (Trematode infection) Blood fluke Schistosoma mansoni / S. japonicum / S. mekongi / S. haematobium / S. intercalatum Schistosomiasis Trichobilharzia regenti Swimmer's itch Liver fluke Clonorchis sinensis Clonorchiasis Dicrocoelium dendriticum / D. hospes Dicrocoeliasis Fasciola hepatica / F. gigantica Fasciolosis Opisthorchis viverrini / O. felineus Opisthorchiasis Lung fluke Paragonimus westermani / P. kellicotti Paragonimiasis Intestinal fluke Echinostoma Echinostomiasis Fasciolopsis buski Fasciolopsiasis Gastrodiscoides hominis Amphistomiasis Heterophyes heterophyes Heterophyiasis Metagonimus yokogawai Metagonimiasis Cestoda (Tapeworm infection) Cyclophyllidea Echinococcus granulosus / E. multilocularis Echinococcosis Taenia saginata / T. asiatica / T. solium (pork) Taeniasis / Cysticercosis Hymenolepis nana / H. diminuta Hymenolepiasis Pseudophyllidea Diphyllobothrium latum Diphyllobothriasis Spirometra erinaceieuropaei Sparganosis Diphyllobothrium mansonoides Sparganosis Roundworm/ Nematode infection Secernentea Spiruria Camallanida Dracunculus medinensis Dracunculiasis Eradication Spirurida Filarioidea (Filariasis) Onchocerca volvulus Onchocerciasis Loa loa Loa loa filariasis Mansonella Mansonelliasis Dirofilaria repens D. immitis Dirofilariasis Wuchereria bancrofti / Brugia malayi / B. timori Lymphatic filariasis Thelazioidea Gnathostoma spinigerum / G. hispidum Gnathostomiasis Thelazia Thelaziasis Spiruroidea Gongylonema Strongylida (hookworm) Hookworm infection Ancylostoma duodenale / A. braziliense Ancylostomiasis / Cutaneous larva migrans Necator americanus Necatoriasis Angiostrongylus cantonensis Angiostrongyliasis Metastrongylus Metastrongylosis Oesophagostomum Oesophagostomiasis Trichostrongylus spp. Trichostrongyliasis Ascaridida Ascaris lumbricoides Ascariasis Anisakis Anisakiasis Toxocara canis / T. cati Visceral larva migrans / Toxocariasis Baylisascaris Dioctophyme renale Dioctophymosis Parascaris equorum Rhabditida Enterobius vermicularis Enterobiasis Strongyloides stercoralis Strongyloidiasis Halicephalobus gingivalis Adenophorea Trichinella spiralis Trichinosis Trichuris trichiura (Trichuriasis / Whipworm) Capillaria philippinensis Intestinal capillariasis C. hepatica

Taxon identifiers Nematoda Wikidata: Q5185 Wikispecies: Nematoda ADW: Nematoda AFD: Nematoda BioLib: 14944 BOLD: 19 CoL: NM EoL: 2715 EPPO: 1NEMAP Fauna Europaea: 11682 Fauna Europaea (new): 79c47bc3-8cdb-4e32-9b9a-55780a5f082c GBIF: 5967481 iNaturalist: 54960 IRMNG: 177 ITIS: 59490 NBN: NBNSYS0000160506 NCBI: 6231 NZOR: eb11dec3-b2ab-40d5-a0f7-4537a2ede17c Open Tree of Life: 395057 Paleobiology Database: 6998 PPE: nematoda WoRMS: 799

Authority control databases International GND National United States France BnF data Japan Czech Republic Spain Latvia Israel Other Yale LUX

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Adapted from the Wikipedia article [Nematode](https://en.wikipedia.org/wiki/Nematode) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Nematode?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.