''Dactylosoma'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of parasitic

alveolates The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major unranked clade or superphylum within Eukaryota. They are currently grouped with the Stramenopiles and Rhizaria among the protists with tubulocristat ...

of the

phylum In biology, a phylum (; : phyla) is a level of classification, or taxonomic rank, that is below Kingdom (biology), kingdom and above Class (biology), class. Traditionally, in botany the term division (taxonomy), division has been used instead ...

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 ...

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

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 ...

host is a

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

(possibly also

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) and the

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 ...

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 tur ...

'').

Taxonomy

This genus was described by Labbé in 1894. The

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 ...

is ''Dactylosoma ranarum''.

Description

Merogony 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 ...

Schizont 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 ...

s 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 i ...

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

erythrocyte Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood ce ...

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 organis ...

: 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 T ...

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 ...

s are formed after fertilization in the leech intestine. 30 or more

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 are produced by exogenous budding directly in the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

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 ''Fejervarya limnocharis'' is a species of frog found in South East Asia and parts of Indochina. It is known under many common names, including Boie's wart frog, rice field frog, and Asian grass frog. Molecular studies of the species complex (af ...

'' 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, Ethiopia, Eswatini, Kenya, Lesotho, Malawi, Mauritius, Mozambiq ...

'' from South Africa. ''Dactylosoma piperis'' was described in 2020 from the pepper frog ''

Leptodactylus labyrinthicus ''Leptodactylus'' is a genus of Leptodactylidae, leptodactylid frogs. It includes the species commonly called ditch frogs or white-lipped frogs. It is very similar to ''Physalaemus'', a close relative, and indeed the 2005 described ''Leptodactylu ...

'' (Anura, Leptodactylidae) from Mato Grosso State,

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

References

Apicomplexa genera Conoidasida {{Apicomplexa-stub