Rev: 10/15/2026
Tetrameres (Diesing, 1835) Creplin, 1846
Type species of the genus: Tetrameres (Tropisurus) paradoxa Diesing, 1835
Synonyms:
Tropisurus Diesing, 1835
Tropidocerca Diesing, 1851
Extreme sexual dimorphism: females swollen, males vermiform.
Females: Males:
Cosmopolitan distribution. Parasitism by Tetrameres spp. is especially prevalent in aquatic birds (Kinsella and Forrester, 2008).
Food Sources and Feeding strategies for the genus Tetrameres
Parasites of the proventriculus of domestic and wild birds
The term tetrameridosis is applied to diseases of wild and domestic birds caused by nematodes of the genera Tetrameres, Microtetrameres and Geopetitia (family Tetrameridae).
Females of Tetrameres and Microtetrameres are typically found embedded in the gastric glands of the proventriculus of bird hosts. One or more males (which are much slaller than females) may be associated with the females in the glands or free in the lumen of the proventriculus.
Tetrameres strigiphila and some other species of Tetrameres encyst in a fibrous capsule in the tunica muscularis of the proventriculus; the female tail extending through an opening into the lumen of the proventriculus for the deposition of eggs. Species of Geopetitia occupy similar cysts in the wall of the esophagus, proventriculus, or the gizzard, but often with several females per cyst rather than one (Anderson 2000).
High levels of infection of Tetrameres spp. result in emaciation, anemia, and death in domestic ducks and chickens. The infections are characterized by enlargement of the proventriculus and thickening of the wall. The females within the glands can be seen through the wall as dark red, slightly raised foci 2�3 mm in diameter, resembling hematomas. The infected proventricular glands may become covered with a foamy, necrotic material. The small ntestinal mucosa may be swollen and covered with mucus and the contents greenish or granular and golden-brown (Popova, 1954; Kinsella and Forrester, 2008).
Life cycle indirect; embryonated eggs are passed in the feces and ingested by intermediate hosts. The definitive hosts are mainly aquatic birds and intermediate hosts are usually crustaceans.
A few species parasitize terrestrial birds, especially passeriforms and galliforms, and, in those cases, intermediate hosts are usually insects, most commonly orthopterans and coleopterans.
In typical aquatic and terestrial life cycles, the juvenile nematodes develop to the infectiv J3 stage in the intermediate host. They are passed to the definitive host when the the intermediate host is ingested by the bird (Kinsella and Forrester, 2008).
Several treatment regimes have been used to treat tetramerid infections in captive birds. A single oral dose of Levamisole to control T. americana in Rock Pigeons (Kinsella and Forrester, 2008).
Anderson R.C. 2000. Nematode Parasites of Vertebrates: Their Development and Transmission. CABI Publishing; Wallingford, UK:
Creplin, F.C.H. 1846. Nachtrage su Gurlt'sVerzeichnissder Thiere, bei welchen Entozoen gefunden worden sind. Arch. Naturgesch, 12:129-160.
Diesing, K. M. 1835. Tropisurus und Thysanosoma, zwey neue gattungen von Binnenwurmen (Entozoen) aus Brasilien. Med. Jahrb. Osterr. St., 7:83-116.
Diesing, K.M. 1851. Systema helminthum. Apud Wilhelmum Braumuller, Vindobonae, 2:vi+l-558.
Kinsella, J.M. and Forrester, D.J. 2008. Tetrameridosis. Chapter 21 in Atkinson, C.T., Thomas, N.J., Hunter, D.B. Parasitic Diseases of Wild Birds. Wiley-Blackwell
Mollhagen, T.R. 1991. A study of the parasituic nematode genus Tetrameres. I. The literature 1835-1985. Special Publications, The Museum, Texas Tech University No. 35.
Mollhagen, T.R. 1976. A study on the systematics and hosts of the parasitic nematode genus Tetrameres (Habrenematoidea: Tetrameridae). PhD. Dissertaion, Zoology, Texas Tech University.
Popova, Z. G. 1954. [Pathological�morphological changes in the glandular stomach of the duck caused by Tetrameres fissispina (Diesing, 1861)] (in Russian). Raboty po Gelmintologiik 75-Letiu Akademika K. I. Skrjabin, Akademia Nauk SSSR, Moskva 547-551.