''Linguatula serrata'' is a species of

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

zoonotic A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...

parasite 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 has ...

, belonging to the tongueworm order

Pentastomida The Pentastomida are an enigmatic group of parasitic arthropods commonly known as tongue worms due to the resemblance of the species of the genus ''Linguatula'' to a vertebrate tongue; molecular studies point to them being degenerate crustaceans ...

. They are wormlike parasites of the respiratory systems of vertebrates. They live in the nasopharyngeal region of mammals.

Cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

fox Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush''). Twelve sp ...

es, and other

carnivores A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other so ...

are normal hosts of this parasite. Apparently, almost any mammal is a potential intermediate host.

Description

The adult parasite is dorsoventrally flattened, tapering backwards resembling a vertebrate tongue, thus, inspiring the common name of "tongueworm." Physical characteristics: males: in length, while the females are .

Distribution

''L. serrata'' can be found worldwide but especially in warm subtropical and temperate regions.

Behavior and ecology

Life cycle

Adult ''L. serrata'' embed their forebody into the nasopharyngeal mucosa, feeding on blood and fluids. Females live at least two years and produce millions of eggs. Eggs exit the host in nasal secretion or, if swallowed, with feces. When swallowed by an intermediate host, the four-legged larvae (resembling a mite) hatch in the small intestine, penetrate the intestinal wall, and lodge in tissues, particularly in lungs, liver, and lymph nodes. The nymphal stage develops. When eaten by a definitive host, infective nymphs either attach in the upper digestive tract or quickly travel there from the stomach, reaching the

nasopharynx 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 struct ...

. Females begin egg production in about six months.

Reproduction

Both male and females are required to mate for successful reproduction. Males choose to mate with females that are close to their own size. Females contain hundreds of thousands of eggs.

Disease

Linguatulosis is a condition associated with the organism ''Linguatula serrata''. More generally, linguatulosis can be considered a form of "pentastomiasis", which refers to all diseases caused by

pentastomid The Pentastomida are an enigmatic group of parasitic arthropods commonly known as tongue worms due to the resemblance of the species of the genus ''Linguatula'' to a vertebrate tongue; molecular studies point to them being degenerate crustaceans. ...

s, including

porocephaliasis Porocephaliasis is a condition associated with species in the closely related genera ''Porocephalus'' and ''Armillifer''. (The term "pentastomiasis" encompasses all diseases of Pentastomida, which includes porocephaliasis and linguatulosis.) Poroc ...

. This disease is often accidentally identified during autopsy because of its asymptomatic effect on the body.

Epidemiology

Among ''Linguatula serrata'' infecting Cairo street dogs, 10% were juveniles, 59% were males, and 31% were females, corresponding to a sex ratio of 1.9:1. Of all infections, 67% were found during spring and summer, compared to 33% during fall and winter. The probable source of canine infections is infected lymph nodes of cattle, sheep, goats, and/or camels, which produce the symptoms of halzoun and the marrara syndrome in man when consumed raw.

References

{{Taxonbar, from=Q3061587 Parasitic crustaceans Cosmopolitan arthropods Crustaceans described in 1789 Taxa named by Josef Aloys Frölich