Diplogastridae, formerly Diplogasteridae, are a family of nematodes (roundworms) known from a wide range of habitats, often in

commensal Commensalism is a long-term biological interaction ( symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fr ...

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

associations with

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

Description

Diplogastrid nematodes are characterized by a distinct "two-lobed"

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its ...

(hence their name from the Greek διπλόος = "double" and γαστήρ = "stomach"), the second ( posterior) lobe being composed mostly of

glandular tissue In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

. Most known species also have at least one tooth, which has presumably allowed them to access many new food sources compared with the related nematodes of

Rhabditidae The Rhabditidae are a family of nematodes which includes the model organism ''Caenorhabditis elegans''. Genera ''Bursilla'' *'' Bursilla monhysteria'' (Butschli, 1873) ''Caenorhabditis'' *''Caenorhabditis brenneri'' Sudhaus & Kiontke, 2007 ...

(including ''

Caenorhabditis elegans ''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' (r ...

''), most species of which feed on

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

. Several diplogastrid species also have a

polyphenism A polyphenic trait is a trait for which multiple, discrete phenotypes can arise from a single genotype as a result of differing environmental conditions. It is therefore a special case of phenotypic plasticity. There are several types of polyphen ...

in their mouthparts, allowing resource specialization within species. The wide array of feeding modes in the Diplogastridae is reflected by the relatively high diversity and complexity of their mouth structures, which show accelerated rates of evolution in comparison with the Rhabditidae. While Sudhaus and Lieven sunk many generic names in their lumping approach of a revision, the Hungarian nematologist Istvan Andrassy was a "splitter", erecting and re-erecting many nematode taxa. The truth might be somewhere in between, as the approaches by Ragsdale and others have shown in recent years. Among the Diplogastridae is the nematode ''

Pristionchus pacificus ''Pristionchus pacificus'' is a species of free-living nematodes (roundworms) in the family Diplogastridae. The species has been established as a satellite model organism to ''Caenorhabditis elegans'', with which it shared a common ancestor 200� ...

'', a model organism for comparative

developmental biology Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of ste ...

Formicodiplogaster myrmenema dauer juvenile

Genera

*'' Acrostichus'' *'' Allodiplogaster'' *'' Anchidiplogaster'' *'' Butlerius'' *'' Cephalobium'' *'' Cutidiplogaster'' *'' Demaniella'' *'' Diplogaster'' *'' Diplogasteriana'' *'' Diplogasteroides'' *'' Diplogastrellus'' *'' Fictor'' *†'' Formicodiplogaster'' (Fossil,

Dominican Amber Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree ''Hymenaea protera''. Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil incl ...

) *'' Goffartia'' *''

Heteropleuronema Heteropleuronema is a monotypic genus of nematodes in the family Diplogastridae. The only species described so far is ''Heteropleuronema unum''. It has been isolated from fungi in Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officia ...

'' *'' Hugotdiplogaster'' *'' Koerneria'' *'' Leptojacobus'' *'' Levipalatum'' *'' Longibucca'' *'' Mehdinema'' *''

Micoletzkya ''Micoletzkya'' is a genus of predatory bark-beetle-associated nematodes in the family Diplogastridae. The genus was named for the Austrian nematologist Heinrich Micoletzky. As of 2013 it consists of 25 described species. Ecology and life histo ...

'' *'' Mononchoides'' *'' Oigolaimella'' *'' Neodiplogaster'' *'' Parapristionchus'' *'' Parasitodiplogaster'' *'' Paroigolaimella'' *'' Pristionchus'' *'' Pseudodiplogasteroides'' *'' Rhabditidoides'' *'' Rhabditolaimus'' *'' Sachsia'' *'' Sudhausia'' *'' Teratodiplogaster'' *'' Tylopharynx''

References

Rhabditida Nematode families Burdigalian first appearances Extant Miocene first appearances {{Chromadorea-stub