Gongylonema		Contents		Rev: 05/28/2026
Gullet Worms, Crop Worms		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Gongylonema Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Gongylonematidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea
Chromadoria

           Rhabditida 

   Spirurina

                          Spiruroidea

                   Gongylonematidae (or Thelaziidae)

                       Gongylonema Molin, 1857

As of 2021, the only genus of the family Gongylonematidae.

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Morphology and Anatomy:

About 50 species described between 1819 and 2016, mainly as parasites of birds and mammals.  Humans are considered accidental hosts for the genus but some cases of infection have been reported.

The genus is characterized by numerous cuticular bosses in the anterior region, a gubernaculum, and markedly unequal spicules (Chabaud, 2009)

Considerable similarity in morphological and morphometric characters that have likely produced a large number of synonymies.  Some of the characters considered most reliable are  cuticularized structures, such as spicules, gubernaculum and eggs, since they do not suffer major variations in size in adults. However, when comparing the species morphometrically, based on data obtained in the original descriptions, a great deal of overlap is noted. Hence, addaitional characters are necessary, such  as shape of the caudal alae, presence or absence of lateral alae, and number of pairs of caudal papillae (Costa Cordeiro et al.., 2018).

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Distribution:

Species of the genus are detected throughout the world (Costa Cordeiro et al, 2018).

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Feeding:

Food Sources and Feeding strategies for the genus Gongylonema

Parasites of birds, mammals, insects.

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Biology and Ecology:

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Life Cycle:

Intestinal parasites of birds and mammals, including humans, although humans considered accidental hosts.  Often found in the buccal region and referred to as gullet worms.. Also in, often in the crop of domestic fowl and referred to as crop worms..

Insects, especially dung beetles, are intermediate hosts. Since dung beetle species are in close contact with animal and human feces, they may also act as hosts for a wide variety of pathogenic bacteria and/or viruses, as well as eukaryotic parasites such as platyhelminthes and nematode  belonging to the genera Gongylonema, Spirocerca, Ascarops, Acanthocephalus, Macracanthorynchus, or Physocephalus (Poinar, 1975). The parasites use dung beetles as intermediate, incidental, or paratenic hosts (Nichols and Gomez, 2014).

Like other spirurid nematodes, Gongylonema spp. the insect intermediate host ingests ingest the eggs and juveniles become encysted in the eggs. When the insect host is ingested by an appropriate definitive host, thethe juveniles emerge from the eggs and migrate to the esophagus or buccal cavity.

(1) Adult Gongylonema inhabit the upper gastrointestinal tract of the definitive host in sites such as the mouth, esophagus, rumen, and stomach. The adults occurs in shallow tunnels in the squamous epithelial surfaces of the tissues; the female produces thick-shelled, embryonated eggs containing first-stage (J1) juveniles. (2)  Expelled eggs are released from the tunnels during epithelial desquamation and are passed down the gastrointestinal tract and shed in the feces. (3) Intermediate host insects become infected after ingesting eggs in feces of definitve hosts. (4) Juveniles develop in the hemocoel of the intermediate host, eventually becoming encapsulated as infective third-stage (J3) juveniles in the thoracic muscles. (5) Definitive hosts become infected after ingesting infected intermediate hosts (6) Juveniles are released in the stomach and embed in the gastric or duodenal mucosa; after 2-3 months they migrate to the upper gastro-intestinal tract. Migration of juveniles often creates characteristic zig-zag or sinusoidal tracks in the affected epithelial tissues. Maturation is completed in the upper gastrointestinal tract. (7) Human infections occur following the ingestion of intermediate host arthropods, either intentionally or accidentally, in contaminated food or water. In these cases, worms have been found in the mucosal tissues of the lips, cheek, tongue, tonsils, gums, and occasionally esophagus. A few cases of spurious egg passage have been documented, which may be due to the inadvertent consumption of adult Gongylonema in certain types of meat (for example, chicken gizzards or pork tongue).  Adapted from Division of Parasitic Diseases and Malaria, United States Centers for Disease Control and Prevention, 2019.

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Ecosystem Functions and Services:

Damage to Hosts

Often found in the buccal region and referred to as gullet worms.. Also often in the crop of domestic fowl and referred to as crop worms..

Humans may become infected by accidental ingestion of infected insects. Various species of dung beetle and cockroaches have been demonstrated to be suitable insect hosts. It has been suggested that most human infections result from ingestion of cockroaches.

In humans, the worms tend to localize in the buccal cavity, including the lips, gums, tongue, and palate. In a high percentage of these cases, the sensation of a moving worm is reported by the patient. In some cases, the worms are removed by the patients themselves, using their fingers. In others, the worms have been removed by inserting a needle under the worm. Symptoms in humans, other than the sensation of something moving, may include local irritation, pharyngitis and stomatitis, and bloody oozing patches in the mouth (Eberhard and Busillo, 1999). Most human infestions appear to be by Gongylonema pulchrum.

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Management:

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References:

Bravo-Barrigo, D., Martin-Perez, M., Lobo, J.M., Parreira, R., Perez-Martin, J.E., Frontera, E. 2021. First detection of Gongylonema species in Geotrupes mutator in Europe. J. Nematology 53: | DOI: 10.21307/jofnem-2021-050

Chabaud, A. G. 2009. Spirurida. In Keys to the nematode parasites of vertebrates: Archival volume, R. C. Anderson, A. G. Chabaud, and S. Willmott (eds.). CAB International, Tucson, Arizona, p. 361-377.

Costa Cordeiro, H., F.T. de Vasconcelos Melo, E. Guerreiro Giese and J. Nascimento dos Santos. 2018. Golygonema parasites of rodents : a key to species and new data on G. neoplasticum. J. Parasitol. 104:51-59.

 Eberhard, M.L. and Busillo, C. 1999. Human Gongylonema infection in a resident of New York City. .Am. J. Trop. Med. Hyg., 61:51-52.

Kinsella, J.M., MR Robles, WC. Preisser. 2016.  A review of Gongylonema spp.(Nematoda: Gongylonematidae) in North American rodents with description of a new species from the cotton rat, Sigmodon hispidus (Mammalia: Cricetidae). Zootaxa, 4107: 277-284.

Nichols, E. and Gomez, A. 2014. Dung beetles and fecal helminth transmission: Patterns, mechanisms and questions. Parasitology 141:614-623.

Poinar, G.O. 1975. Entomogenous nematodes: A manual and host list of insect-nematode associations. Leiden: Brill Archive.

Radev, V. 2024. Spirurida (Order). Chapter 53 in In S. L. Gardner and S. A. Gardner, eds. Concepts in Animal Parasitology. Zea Books, Lincoln, Nebraska, United States. doi:10.32873/unl.dc.ciap053

United States Centers for Disease Control and Prevention, 2019. Division of Parasitic Diseases and Malaria.

Copyright © 1999 by Howard Ferris.
Revised: May 28, 2026.