Belongs within: Secernentea. The Ascaridomorpha are a group of often large roundworms parasitic in vertebrates. The small intestinal roundworm Ascaris lumbricoides inhabits the gut of humans, in which it is the most abundant parasitic worm worldwide. Ascaridomorpha [Ascaridida] | i. s.: PolydelphisJ02 | Pseudoterranova decipiensJ02 [=Phocanema decipiensL02b, Terranova decipiensL02c] | Metaterakis govindiJ02 | Nematoxys ornatusH02… Continue reading Ascaridomorpha


Belongs within: Cycloneuralia.Contains: Gordionus. The Nematomorpha, Gordian or horsehair worms, are a group of elongate worms that are parasitic as larvae on insects or crustaceans, emerging into water upon maturity. A single genus Nectonema is marine and bears dorsal and ventral rows of cuticular natatory bristles as an adult; the remaining genera (forming the taxon… Continue reading Nematomorpha


Belongs within: Dorylaimia. The Mermithida are a group of nematodes that are parasitic on insects and other invertebrates. Members of the family Mermithidae emerge from the host as adults to breed whereas Tetradonematidae remain in their host. Fossil mermithids found in Dominican and Baltic amber have been assigned to the genus Heydonius (Poinar 1992). Characters… Continue reading Mermithida


Belongs within: Cycloneuralia.Contains: Aphanolaimidae. The Plectida are a group of terrestrial and aquatic free-living nematodes with cephalic setae, a cylindrical stoma and unispiral amphids. <==Plectida [Leptolaimina] |–HaliplectoideaLB02 | |–HaliplectidaeLB02 | |–AulolaimidaeLB02 | `–Manunema Gerlach 1957L86 [PeresianidaeLB02] | `–M. proboscidisL86 |–CeramonematoideaLB02 | |–TarvaiidaeLB02 | |–TubolaimoididaeLB02 | `–Ceramonema [Ceramonematidae]LB02 | `–C. carinatumL02b |–PlectoideaLB02 | | i. s.:… Continue reading Plectida


Belongs within: Secernentea. The Oxyuridomorpha are a group of animal-parasitic nematodes characterised by the possession of a large, valvate esophageal bulb. Members of the superfamily Thelastomatoidea are parasites of insects whereas Oxyuroidea mostly infect vertebrates. Oxyuridomorpha [Oxyurida] | i. s.: Blatticola monandrosWPT01 | Protellus dixoniWPT01 | Hammerschmidtiella diesingiL02 | Aspiculuris tetrapteraJ02, P02 | AuchenacanthaJ02 |… Continue reading Oxyuridomorpha


Belongs within: Rhabditina. The Rhabditoidea is an assemblage of free-living nematodes, though it is probably paraphyletic to parasitic groups such as the Strongyloidea. Members of the Rhabditoidea are characterised by having the phasmid in males posterior to all other bursal rays (Ley & Blaxter 2002). The bacteriovorous Caenorhabditis elegans has become a model organism in… Continue reading Rhabditoidea


Belongs within: Secernentea.Contains: Rhabditoidea, Strongyloidea, Cylindrocorporidae. The Rhabditina is a group of nematodes including both free-living and animal-parasitic forms. Possible synapomorphies of the group include the presence of a bursa with rays in the male, and a short muscular part to the stegostom, consisting of less than four muscle sets in at least the juvenile… Continue reading Rhabditina


Belongs within: Tylenchida.Contains: Ecphyadophoroidinae, Tylenchinae, Boleodorinae, Duosulciinae. The Tylenchoidea are a group of nematodes including free-living feeders on soil fungi and algae, and parasites (both external and internal) of plant tissues. Characters (from Maggenti et al. 1987): Lip region generally hexaradiate and distinguished from general body contour. Labial region supported by a cuticularized skeleton that… Continue reading Tylenchoidea


Belongs within: Cycloneuralia.Contains: Mermithida, Mononchida, Dorylaimina. The Dorylaimia is a clade of freshwater and soil-dwelling nematodes supported by molecular phylogenetic analysis (Ley & Blaxter 2002). <==Dorylaimia |–+–+–MermithidaLB02 | | `–MononchidaLB02 | `–DorylaimidaLB02 | | i. s.: EudorylaimusH02 | | Chrysonema aurumWI89 | |–DorylaiminaLB02 | |–Campydoridae [Campydorina, Campydoroidea]LB02 | `–Nygolaimina [Nygolaimoidea]LB02 | |–NygellidaeLB02 | |–AetholaimidaeLB02 |… Continue reading Dorylaimia


Belongs within: Dorylaimia. The Mononchida are a group of mostly soil-dwelling (rarely freshwater) predatory nematodes. Characters (from Ahmad & Jairajpuri 2010): Medium to large nematodes, generally well over 1 mm long. Lip region expanded, lips and labial papillae well expanded. Buccal cavity spacious, strongly sclerotised, posterior quarter or entire length embedded in pharyngeal tissue, provided… Continue reading Mononchida