''Adeleorina'' is a suborder of parasites in the phylum

Apicomplexa The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an ap ...

History

Léger proposed this taxon in 1911. The first species identified was '' Dactylosoma ranarum'' by Lankester (1871) in a frog in Europe. It was initially called ''Undulina ranarum'', but this was changed in 1882 to ''Drepanidium ranarum''. This species was subsequently moved to the genus ''Dactylosoma''. Canine hepatozoonosis was first described in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

in 1905 by James. The organism was named ''Leukocytozoon canis''. The vector was identified in 1907 by Christopher to be the brown dog tick (''

Rhipicephalus sanguineus ''Rhipicephalus sanguineus'', commonly called the brown dog tick, kennel tick, or pantropical dog tick, is a species of tick found worldwide, but more commonly in warmer climates. This species is unusual among ticks in that its entire biological ...

''). The genus '' Hepatozoon'' was created by Miller in 1908 for a parasite of the white rat (''

Rattus norvegicus ''Rattus'' is a genus of muroid rodents, all typically called rats. However, the term rat can also be applied to rodent species outside of this genus. Species and description The best-known ''Rattus'' species are the black rat (''R. rattus' ...

'') that underwent merogony in the

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

and sporogony in the

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

'' Laelap echidinus''. Ledger initially placed this genus in the family Haemogregarinidae, but Wenyon subsequently removed it and placed it in the newly created taxon Hepatozoidae in 1926.

Life cycle

All species in this suborder use the syzygy method of

gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...

formation. This involves the association of often motile gamonts prior to the formation of functional gametes and fertilization. Their life cycles tend to be complex, involving at least one (and often several) asexual cycles of merogony followed by gametogony,

syngamy Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or of ...

and sporogony. In many species of the group, the meronts and merozoites have morphologically distinct types: one type of meront produces large merozoites which initiate a further round of merogonic replication; a second produces smaller merozoites which are the progenitors of the gamonts. Microgamonts produce usually only one to four microgametes. Other characteristic features include the absence of endodyogeny and the enclosure of

sporozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organis ...

s in a sporocyst. In haemogregarines with

heteroxenous 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 d ...

species,

conjugation Conjugation or conjugate may refer to: Linguistics *Grammatical conjugation, the modification of a verb from its basic form *Emotive conjugation or Russell's conjugation, the use of loaded language Mathematics *Complex conjugation, the change o ...

of gamonts and subsequent sporogony usually occurs within an invertebrate (definitive host), which also serves as the

vector Vector most often refers to: * Euclidean vector, a quantity with a magnitude and a direction * Disease vector, an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematics a ...

. Merogonial division usually takes place in the parenchymatous organs of the vertebrate host. This is followed by the formation of infective gametocytes in the erythrocytes. In the genus '' Hepatozoon'', gametocytes are also formed in the leukocytes. The haemogregarines use two modes of transmission: * Inoculation — the infectious sporozoites enter the vertebrate host during blood-feeding of the vector ('' Dactylosoma'', '' Haemogregarina'') * Ingestion — the parasite is transmitted by the ingestion of the infected invertebrate host by the vertebrate host. The mode of transmission may even involve a paratenic host. The next definitive host in the life cycle is infected exclusively through blood feeding. Examples include the genera '' Karyolysus'', '' Hemolivia'' and '' Hepatozoon''.

Taxonomy

Adeleorina has about 500 species, which have been organised into seven families and 19 genera. The families have been divided into two groups: *Adelines — monoxenous coccidians of

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s — Adeleidae and Legerellidae *Haemogregarines —

coccidians cycling between blood-sucking invertebrates (definitive hosts) and various

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

s (intermediate hosts) — Dactylosomatidae, Haemogregarinidae, Hepatozoidae and Karyolysidae One exception to this classification is known: '' Klossiella'' (family Klossiellidae) is a monoxenous coccidium of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s and

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s. The taxonomy is this group may be incorrect as the Hepatozoidae appear to be paraphyletic. The genus ''Hemolivia'' appears to lie within the genus ''Hepatozoon''. The genus ''Hepatozoon'' appears to have two subgenera with one in the carnivorous mammals and the other in lower vertebrates and rodents.

Families and genera

The families in this suborder are: *Family Adeleidae Mesnil, 1903 **Genera: ***'' Chagasella'' Machado in 1911 ***'' Ganapatiella'' Kalavati, 1977 ***'' Gibbsia'' Levine, 1986 ***'' Klossia'' Schneiderin, 1875 ***'' Orcheobius'' Schuberg & Kunze, 1906 ***'' Rasajeyna'' Beesley, 1977 **Subfamily Ithaniinae ***Genera ****'' Adelea'' Schneider, 1875 ****'' Adelina'' Hesse, 1911 ****'' Ithania'' Ludwigin, 1947 *Family Dactylosomatidae Jakowska & Nigrelli, 1955 **Genera: ***'' Babesiosoma'' Jakowska & Nigrelli, 1956 ***'' Dactylosoma'' Labbé, 1894 *Family Haemogregarinidae Neveu-Lemaire, 1901 **Genera: ***'' Cyrilia'' Lainson, 1981 ***'' Desseria'' Siddall, 1995 ***'' Haemogregarina'' Danilewsky, 1885 *Family Hepatozoidae Wenyon, 1926 **Genera: ***'' Hepatozoon'' Miller, 1908 *Family Karyolysidae Wenyon, 1926 **Genera: ***'' Karyolysus'' Labbé, 1894 ***'' Hemolivia'' Petit ''et al'', 1990 *Family Klossiellidae Smith & Johnson, 1902 **Genera: ***'' Klossiella'' *Family '' Legerellidae'' Minchin, 1903 **Genera: ***'' Legerella'' Mesnil, 1900

Notes

''Karyolysus'' infects lizards ('' Lacerta'') and possibly scincids. ''Haemogregarina'' infects turtles and leeches. Species of the genus ''Desseria'' infect fish and lack erythrocytic merogony. The genera in the subfamily Ithaniinae share a number of morphological features and infect the digestive tract of insects. DNA studies suggest ''Hemolivia'' may lie within the ''Hepatozoon'' clade. If this can be confirmed, the taxonomy of this group will need revision. A study of the 18s rRNA gene suggests that there may be some overlap between ''Karyolysus'' and ''Hepatozoon''. Karadjian, Chavatte and Landau revised the Adeleidae in 2015, performed a molecular analysis and proposed a new classification in four 'types' based on their biology, as follows: *Type I, '' Hepatozoon'' Miller, 1908, with

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''H. perniciosum'' Miller, 1908 *Type II, '' Karyolysus'' Labbé, 1894, with type species ''K. lacertae'' (Danilewsky, 1886) Reichenow, 1913 *Type III '' Hemolivia'' Petit et al., 1990, with type species ''H. stellata'' Petit et al., 1990 *Type IV: '' Bartazoon'' Karadjian, Chavatte and Landau, 2015, with type species ''B. breinli'' (Mackerras, 1960).

References

{{Taxonbar, from=Q4681918 Apicomplexa suborders Conoidasida Parasites of bats Parasites of dogs Parasites of amphibians