Gongylonema is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of thread-like nematode

Nematode

The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

 that was discovered in 1850 by Joseph Leidy

Joseph Leidy

Joseph Leidy was an American paleontologist.Leidy was professor of anatomy at the University of Pennsylvania, and later was a professor of natural history at Swarthmore College. His book Extinct Fauna of Dakota and Nebraska contained many species not previously described and many previously...

and described by Molin in 1857. It is the only currently valid genus in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Gongylonematidae, though the mysterious Spiruroides – usually placed in the Subuluridae

Subuluridae

Subuluridae is a family of spirurian nematodes which, together with the two species of Maupasinidae, make up the superfamily Subuluroidea. Like all nematodes, they have neither a circulatory nor a respiratory system....

, which are not closely related to Gongylonema among the Spiruria

Spiruria

Subclass Spiruria comprises mostly parasitic secernentean nematodes. In an alternate classification, they are treated as suborder Spirurina, with the orders listed here being ranked as infraorders....

 – might actually belong here. They are parasites of bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s and mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s, transmitted by insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s (especially beetle

Beetle

Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

s). Some 38 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 are known, about 12 of which have been recorded in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

.

Several species are significant parasites of domestic animals, causing gongylonemiasis. Human infection by these nematodes is very rare: since its discovery there were less than 100 people reported to be infected with these parasites, always with the species G. pulchrum

Gongylonema pulchrum

Gonglylonema pulchrum is the only parasite of the genus Gongylonema capable of infecting humans.Gongylonema pulchrum infections are due to humans acting as accidental hosts for the parasite. There are seven genera of spirudia nematodes that infect human hosts accidentally: gnoathostoma, thelazia,...

.