Diplogastridae, formerly Diplogasteridae, are a family of

nematode The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...

s (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 f ...

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

associations with

insects Insects (from Latin ') are 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 of jointed ...

Description

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

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

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

glandular tissue A gland is a cell or an organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. A gland may also function to remove unwanted substances ...

. 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 A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in t ...

(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 Hybrid word, blend of the Greek ''caeno-'' (recent), ''r ...

''), most species of which feed on

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

. 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 (biology), regeneration, asexual reproduction, metamorphosis, and the growth and di ...

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 in ...

) *'' Goffartia'' *'' Heteropleuronema'' *'' Hugotdiplogaster'' *'' Koerneria'' *'' Leptojacobus'' *'' Levipalatum'' *'' Longibucca'' *'' Mehdinema'' *'' Micoletzkya'' *'' Mononchoides'' *'' Oigolaimella'' *'' Onthodiplogaster'' *'' 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