The turkey is a large bird in the genus Meleagris, native to North America. There are two extant turkey species: the wild turkey of eastern and central North America and the ocellated turkey of the Yucatán Peninsula in Mexico. Males of both turkey species have a distinctive fleshy wattle, called a snood, that hangs from the top of the beak. They are among the largest birds in their ranges. As with many large ground-feeding birds, the male is bigger and much more colorful than the female.
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist guest (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms, cells harbouring pathogenic (disease-causing) viruses, a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner.
Ascaridia galli is a parasitic roundworm belonging to the phylum Nematoda. Nematodes of the genus Ascaridia are essentially intestinal parasites of birds. A. galli is the most prevalent and pathogenic species, especially in domestic fowl, Gallus domesticus. It causes ascaridiasis, a disease of poultry due to heavy worm infection, particularly in chickens and turkeys. It inhabits the small intestine, and can be occasionally seen in commercial eggs.
Histomonas meleagridis is a species of parasitic protozoan that infects a wide range of birds including chickens, turkeys, peafowl, quail and pheasants, causing infectious enterohepatitis, or histomoniasis. H. meleagridis can infect many birds, but it is most deadly in turkeys. It inhabits the lumen of cecum and parenchyma of liver, where it causes extensive necrosis. It is transmitted by another cecal parasite, the nematode Heterakis gallinarum.
A gapeworm, also known as a red worm and forked worm, is a parasitic nematode worm that infects the tracheas of certain birds. The resulting disease, known as "gape" occurs when the worms clog and obstruct the airway. The worms are also known as "red worms" or "forked worms" due to their red color and the permanent procreative conjunction of males and females. Gapeworms are common in young, domesticated chickens and turkeys.
Gongylonema is a genus of thread-like nematode that was described by Molin in 1857. It is the only currently valid genus in the family Gongylonematidae, though the mysterious Spiruroides – usually placed in the Subuluridae, which are not closely related to Gongylonema among the Spiruria – might actually belong here. They are parasites of birds and mammals, transmitted by insects. Some 38 species are known, about 12 of which have been recorded in Europe.
Leucocytozoon is a genus of parasitic alveolates belonging to the phylum Apicomplexa.
Mesostigmata is an order of mites belonging to the Parasitiformes. They are by far the largest group of Parasitiformes, with over 8,000 species in 130 families. Mesostigmata includes parasitic as well as free-living and predatory forms. They can be recognized by the single pair of spiracles positioned laterally on the body.
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.
Tylenchorhynchus is a genus of nematodes including many species of plant parasites. The classification of stunt nematodes - those including the genus Tylenchorhynchus - is unstable; many newly discovered species within this genus are reconsidered to be actually subspecies. Stunt nematodes such as Tylenchorhynchus and the closely related genera, Anguillulina and Merlinia, include more than 250 known species. Members of these genera possess similar anatomy and may be easily mistaken for one another. Some debate has led to the classification of single species under different names in two distinct genera.
The nematodes or roundworms constitute the phylum Nematoda, with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broad range of environments. Less formally, they are categorized as helminths, but are taxonomically classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa, and unlike flatworms, have tubular digestive systems with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum.
The Onchocercidae are a family of nematodes in the superfamily Filarioidea. This family includes some of the most devastating human parasitic diseases, such as lymphatic filariasis, onchocerciasis, loiasis, and other filariases.
Thelazia is a genus of nematode worms which parasitize the eyes and associated tissues of various bird and mammal hosts, including humans. They are often called "eyeworms", and infestation with Thelazia species is referred to as "thelaziasis". Adults are usually found in the eyelids, tear glands, tear ducts, or the so-called "third eyelid". Occasionally, they are found in the eyeball itself, either under the conjunctiva or in the vitreous cavity of the eyeball. All species of Thelazia for which the life cycle has been studied are transmitted by species of Diptera (flies) which do not bite, but which feed on tears.
Heterakis gallinarum is a nematode parasite that lives in the cecum of some galliform birds, particularly in ground feeders such as domestic chickens and turkeys. It causes infection that is mildly pathogenic. However, it often carries a protozoan parasite Histomonas meleagridis which causes of histomoniasis. Transmission of H. meleagridis is through the H. gallinarum egg. H. gallinarum is about 1–2 cm in length with a sharply pointed tail and a preanal sucker. The parasite is a diecious species with marked sexual dimorphism. Males are smaller and shorter, measuring around 9 mm in length, with a unique bent tail. Females are stouter and longer, measuring roughly 13 mm in length, with a straight tail end.
Ascaridia is a genus of parasitic nematodes. Members of the genus are primarily intestinal parasites of birds. Three species are well known, namely, A. galli found mostly in chickens, A. dissimilis in turkeys, and A. columbae in pigeons. Lesser known species such as A. hermaphrodita, A. sergiomeirai, A. ornata, A. nicobarensis, and A. platyceri are found in parrots.
Raillietina is a genus of tapeworms that includes helminth parasites of vertebrates, mostly of birds. The genus was named in 1920 in honour of a French veterinarian and helminthologist, Louis-Joseph Alcide Railliet. Of the 37 species recorded under the genus, Raillietina demerariensis, R. asiatica, and R. formsana are the only species reported from humans, while the rest are found in birds. R. echinobothrida, R. tetragona, and R. cesticillus are the most important species in terms of prevalence and pathogenicity among wild and domestic birds.
Raillietina echinobothrida is a parasitic tapeworm belonging to the class Cestoda. It is the most prevalent and pathogenic helminth parasite in birds, particularly in domestic fowl, Gallus domesticus Linnaeus, 1758. It requires two hosts, birds and ants, for completion of its life cycle. It is a hermaphrodite worm having both the male and female reproductive organs in its body. The parasite is responsible for 'nodular tapeworm disease' in poultry.
Heterakis is a genus of parasitic nematodes. Members of the genus are minute roundworms (pinworms), hardly 1 cm long, infecting different species of gallinaceous birds, including chickens, turkeys, ducks, geese, grouse, guineafowl, partridges, pheasants, and quail. About 10 species are placed in the genus, but classification is often ambiguous due to their close resemblance, and a number of synonyms have arisen. H. gallinarumSchrank, 1788; H. isolonchevon Linstow, 1906; and H. disparSchrank, 1870 are the best understood species in terms of prevalence, pathogenicity, and biology. They inhabit the lumen of the cecum of the host.
Histomoniasis is a commercially significant disease of poultry, particularly of chickens and turkeys, due to parasitic infection of a protozoan, Histomonas meleagridis. The protozoan is transmitted to the bird by the nematode parasite Heterakis gallinarum. H. meleagridis resides within the eggs of H. gallinarum, so birds ingest the parasites along with contaminated soil or food. Earthworms can also act as a paratenic host.
Habronema is a genus of nematodes in the order Spirurida.
