The species in this genus have two vertebrate hosts in their life cycle: a canid (the definitive host) and prey species (the intermediate host). They are strictly heteroxenous.
|
|
Many rust fungi have heteroecious life cycles:Schumann, G. & D'Arcy, C. (2010). Essential plant pathology. APS Press In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several hosts.
|
|
Some trypanosomatids only occupy a single host, while many others are heteroxenous: they live in more than one host species over their life cycle. This heteroxenous life cycle typically includes the intestine of a bloodsucking insect and the blood and/or tissues of a vertebrate. Rarer hosts include other bloodsucking invertebrates, such as leeches, and other organisms such as plants. Different species go through a range of different morphologies at different stages of the life cycle, with most having at least two different morphologies.
|
|
Several other genera of heteroxenous and cyst-forming coccidia are known, including Besnoitia, Cystoisospora, Frenkelia, Hammondia, Neospora and Toxoplasma. Related but monoxenous spore-forming genera include Isospora. Differentiating these genera from Sarcocystis in diagnostic material may be difficult without immunochemical stains.
|
|
Although polar rings and rhoptries are present other typical Apicomplexian features including conoid, flagellae, oocysts, sporocysts and pseudocysts are absent. The species parasitises erythrocytes. It is heteroxenous with merogony and gamogony in the vertebrate host. Fertilization and sporogony in the invertebrate host.
|
|
Pseudoklossia is a genus in the phylum Apicomplexa. Species in this genus infect marine molluscs, although one species (Pseudoklossia microcosmi) infects in an ascidian worm. The life cycle is heteroxenous (requires at least two hosts). The species infecting molluscs tend to infect the renal tissue.
|
|
The genus name Paleoleishmania is derived from the Greek paleo meaning "old" and leishmania referencing the modern Leishmaniasis-causing genus Leishmania. All trypanosomes are heteroxenous (requiring more than one obligatory host in order to complete life cycle) or are transmitted through some variation of a vector.
|
|
Only the development within gilthead sea bream is currently known. Since some of the closest relatives of E. nucleophila infect crustaceans (e.g., Enterospora canceri or E. hepatopenaei), and some of them have heteroxenous cycles alternating between crustacean and fish hosts (e.g., Desmozoon lepeophtheri [3]), a similar alternating cycle could occur for E. nucleophila.
|
|
More ambiguously, these terms are sometimes synonymized as dixenous or trixenous. The etymology of the terms heteroxeny / heteroxenous derives from the two ancient Greek words (), meaning "other, another, different", and (), meaning "foreign". In mycology, the term heteroecious has also been used for parasitic fungi with multiple hosts, and the terms can be used synonymously.
|
|
Coral reef fish are characterized by high biodiversity. As a consequence parasites of coral reef fish show tremendous variety. Parasites of coral reef fish include nematodes, Platyhelminthes (cestodes, digeneans, and monogeneans), leeches, parasitic crustaceans such as isopods and copepods, and various microorganisms such as myxosporidia and microsporidia. Some of these fish parasites have heteroxenous life cycles (i.e.
|
|
The species in this family are heteroxenous, meaning they live in two separate hosts during their life cycle. The two host species involved in their life cycle are a crustacean and a mollusc. The life cycle involves vegetative development in digestive tract of a decapod crustacean and sporogony in the connective tissue of a lamellibranch mollusc.
|
|
Trypanosoma is a genus of kinetoplastids (class Trypanosomatidae), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous (requiring more than one obligatory host to complete life cycle) and most are transmitted via a vector.
|
|
A dixenous life cycle: the apicomplexan parasitic protist Babesia microti and its two different taxonomic hosts, the deer tick and the white-footed mouse. Heteroxeny, or heteroxenous development, characterizes a parasite whose development involves several host species. Heteroxeny has been used as the basis for splitting genera. When there are two or three hosts, the development cycle is named diheteroxenous or triheteroxenous, respectively.
|
|
Hammondia hammondi is a species of obligate heteroxenous parasitic alveolates of domestic cats (final host). Intracellular cysts develop mainly in striated muscle. After the ingestion of cysts by cats, a multiplicative cycle precedes the development of gametocytes in the epithelium of the small intestine (each oocyst of the species averaging 11×13 μm). Oocyst shedding persists for 10 to 28 days followed by immunity.
|
|
It is an ectoparasite that attaches itself to the outside of its host and feeds on the hosts blood meal. It can have a heteroxenous lifestyle or monoxenous life cycle depending on how many hosts it feeds on in each cycle. I. pacificus has a four stage life cycle that takes around 3 years to complete. These stages include egg, larva, nymph, and adult.
|
|
Neospora caninum has a heteroxenous life cycle, with the sexually reproductive stage occurring in the intestine of a definitive host. Until recently, the only known definitive host was the domestic dog. New research has determined that other canids such as coyotes (Canis latrans), gray wolves (Canis lupus), and Australian dingos (Canis lupus dingo) are also definitive hosts. Oocysts passed in the feces of the definitive host, such as canines or canids, are ingested by an intermediate host, such as cattle.
|
|
There is relatively little known about the life cycle of Bertiella, but inferences and assumptions can be made about it through observations of specific parts of the worm, and knowledge of other cases in the same family (Anoplocephalidae). Anoplocephalids are heteroxenous parasites and require both an intermediate and definitive host to complete their cycle. For Bertiella, nonhuman primates are generally the definitive host, and oribatid mites are the intermediate host. Human infection occurs when a person inadvertently consumes an oribatid mite infected with Bertiella larvae.
|
|
Of these 24, the two main families that are infected by Phytomonas are Euphorbiaceae and Asclepiadiacae. These protists have been found in hosts between 50° latitude North and South, and thus they can be found on all continents save for Antarctica. Phytomonas is believed to have arose from a single monoxenous lineage of insect parasitizing trypanosomatids some 400 million years ago. After this divergence, a heteroxenous lifestyle was developed, and most Phytomonas species are transferred between plant hosts by insect vectors in the Heteroptera suborder as a form of dixenous parasitism.
|
|
The heteroxenous (more than one obligatory host) lifecycle of these apicomplexan parasites remained obscure until 1972, when the prey- predator relationship of its definitive and intermediate hosts was recognised. The lifecycles of about 60 of these species are now known. In outline gametogony and sporogony occur in the intestine of the definitive host, while both schizogony, which occurs in various tissues, and the formation of sarcocysts (containing bradyzoites and metrocytes) occurs principally in the muscles of the intermediate host. In some cases, a single species may act as both the definitive and intermediate hosts.
|
|
Finally, in 1982, Dollet successfully cultivated trypanosomatids in vitro, which allowed for the isolation of Phytomonas in 24 different plant families from across the globe. While there has been recent genetic work done on Phytomonas species, genome level analysis is limited compared to the genome data available for disease causing trypanosomatids in animals and humans, especially Trypanosoma cruzi, Trypanosoma brucei, and Leishmania major. In 2015, Phytomonas nordicus was found to be a part of the generally heteroxenous genus Phytomonas, despite it being a monoxenous parasite of the predatory bug Troilus luridus. The species was described earlier in 1993.
|
|
Nineteen families, three subfamilies, and 70 genera are recognised in this order. The genera include: Adelea, Adelina, Aggregata, Alveocystis, Atoxoplasma, Babesiosoma, Barrouxia, Bartazoon, Besnoitia, Calyptospora, Caryospora, Caryotropha, Chagasella, Choleoeimeria, Cryptosporidium, Crystallospora, Cyclospora, Cyrilia, Cystoisospora, Dactylosoma, Desseria, Diaspora, Dorisa, Dorisiella, Eimeria, Elleipsisoma, Epieimeria, Frenkelia, Ganapatiella, Gibbsia, Goussia, Gousseffia, Grasseella, Hammondia, Haemogregarina, Hemolivia, Hepatozoon, Heydornia, Hoarella, Hyaloklossia, Isospora, Ithania, Karyolysus, Klossia, Klossiella, Lankesterella, Legerella, Margolisiella, Mantonella, Merocystis, Nephroisospora, Neospora, Octosporella, Orcheobius, Ovivora, Pfeifferinella, Polysporella, Pseudoklossia, Pythonella, Rasajeyna, Sarcocystis, Schellackia, Selenococcidium, Selysina, Sivatoshella, Skrjabinella, Spirocystis, Toxoplasma, Tyzzeria, Wenyonella Among the heteroxenous and cyst-forming genera are: Besnoitia, Cystoisospora, Frenkelia, Hammondia, Neospora, Sarcocystis, and Toxoplasma.
|
|
Trypanosoma antiquus is an extinct species of kinetoplastid (class Kinetoplastida), a monophyletic group of unicellular parasitic flagellate protozoa. The genus name is derived from the Greek trypano (borer) and soma (body) because of their corkscrew-like motion, and the species name from antiquua (old) reflecting the age of the specimen. All trypanosomes are heteroxenous (requiring more than one obligatory host in order to complete life cycle) or are transmitted through some variation of a vector. The species was described in 2005 by George Poinar Jr. in the journal Vector-Borne & Zoonotic Diseases from metatrypanosomes preserved in several fecal pellets encased in Hymenaea protera amber.
|
|