''Dactylosoma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of parasitic alveolates of the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Apicomplexia The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic Alveolata, alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex stru ...

. Species in this genus have two hosts in their life cycle: the

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

host is a

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

(possibly also

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

s) and the

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

host is a glossiphoniid leech (''

Glossiphoniidae Glossiphoniidae are a family of freshwater proboscis-bearing leeches. These leeches are generally flattened, and have a poorly defined anterior sucker. Most suck the blood of freshwater vertebrates like amphibians, crocodilians and aquatic tu ...

'').

Taxonomy

This genus was described by Labbé in 1894. The

type species In 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 species that contains the biological type specimen ...

is ''Dactylosoma ranarum''.

Description

Merogony: Schizonts in this genus produce 6 to 16

merozoite 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 organism is ...

s by simultaneous exogenous budding. These typically are found in a fan shaped arrangement. This occurs within the

erythrocyte Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

s. Secondary merogony produces 6 smaller merozoites that are destined to become intraerythrocytic gamonts.

Gametogony 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 organism i ...

: The

gametocyte A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called ''spermatocytes'', and female gametocytes are called ''oocytes''. Development ...

s are larger, elongated forms derived from some of the

Oocyst 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 organism i ...

s are formed after fertilization in the leech intestine. 30 or more sporozoites are produced by exogenous budding directly in the

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...

of the intestinal epithelial cells. No oocyst wall is formed.

Species

Úngari et al. (2020) recognised six species of ''Dactylosoma'' known globally. Two of these are described from fish hosts, and the remaining four species from anuran hosts, namely ''Dactylosoma ranarum'' (Kruse, 1890) described from the European frog ''Pelophylax'' kl. ''esculentus''; ''Dactylosoma sylvatica'' Fanthan, Porter and Richardson, 1942 reported in '' Lithobates sylvatica'' from Quebec, Canada; ''Dactylosoma taiwanensis'' Manwell, 1964 described infecting '' Fejervarya limnocharis'' collected in Taiwan; and ''Dactylosoma kermiti'' described infecting the anurans, '' Ptychadena anchietae'' and ''

Sclerophrys gutturalis The African common toad or guttural toad (''Sclerophrys gutturalis'') is a species of toad in the family Bufonidae. It is found in Angola, Botswana, Democratic Republic of the Congo, Kenya, Lesotho, Malawi, Mauritius, Mozambique, Namibia, Réunion ...

'' from South Africa. ''Dactylosoma piperis'' was described in 2020 from the pepper frog '' Leptodactylus labyrinthicus'' (Anura, Leptodactylidae) from Mato Grosso State,

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

References

Apicomplexa genera {{Apicomplexa-stub