The family Vampyrellidae is a subgroup of the order

Aconchulinida Aconchulinida is an order of Cercozoa in the subclass Filosia. The outer zone is clear ectoplasm and has many vacuoles. It has a single nucleus. Its size range from 10 to 400 micrometers. It contains few genera Genus ( plural genera ) is a ...

(formerly Vampyrellida) within the phylum

Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major ...

. Based on molecular sequence data, the family currently comprises the genus ''

Vampyrella ''Vampyrella'' is a genus of amoebae belonging to the vampyrellid cercozoans usually ranging from 30-60 µm. Members of the genus alternate between two life stages: a free-living trophozoite stage and a cyst stage in which mitosis occurs. ...

'', and maybe several other vampyrellid amoebae (e.g. ''Gobiella''). The cells are naked and characterised by radiating, filose

pseudopodia A pseudopod or pseudopodium (plural: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that is emerged in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filament ...

(also referred to as

filopodia Filopodia (singular filopodium) are slender cytoplasmic projections that extend beyond the leading edge of lamellipodia in migrating cells. Within the lamellipodium, actin ribs are known as ''microspikes'', and when they extend beyond the lame ...

) and an orange colouration of the main cell body. In former times the family Vampyrellidae contained several genera (e.g. ''Vampyrella'', ''Gobiella'', ''Leptophrys'', ''Platyreta'', ''Theratromyxa'') and was identical with the order Vampyrellida West, 1901, also known under the name "Aconchulinida". However, based on molecular sequence data it seemed reasonable to restrict the family Vampyrellidae to a subgroup (containing the genus ''Vampyrella'') and to establish another family for the genera ''Leptophrys'', ''Platyreta'' and ''Theratromyxa'', namely the Leptophryidae Hess et al., 2012.

Characteristics

When free-floating, the cell is spherical and around 30 μm across, with long radially directed filose pseudopods as well as distinctive shorter club-shaped ones, so that it resembles a

heliozoa Heliozoa, commonly known as sun-animalcules, are microbial eukaryotes ( protists) with stiff arms (axopodia) radiating from their spherical bodies, which are responsible for their common name. The axopodia are microtubule-supported projections fr ...

n. Moving, the cell stretches out and takes a more typical

amoeboid An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopo ...

form, with an obvious distinction between the clear periphery and pseudopods and the greenish interior. In this form it finds its way into

alga Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

e cells and feeds on their interiors. At least one genus, Theratromyxa, also feeds on soil nematodes. A few other vampyrellids are

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...

. As such, these vampyrellids can be an important control of parasitic

rust fungus Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales (previously known as Uredinales). An estimated 168 rust genera and approximately 7,000 species, more than half of which belong to the genus ''Puccinia'', are currently ...

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

and other crops. Vampyrellids characteristically have

mitochondria A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

with tubular

crista A crista (; plural cristae) is a fold in the inner membrane of a mitochondrion. The name is from the Latin for ''crest'' or ''plume'', and it gives the inner membrane its characteristic wrinkled shape, providing a large amount of surface area fo ...

e. Together with the

nucleariid Nucleariida is a group of amoebae with filose pseudopods, known mostly from soils and freshwater. They are distinguished from the superficially similar vampyrellids mainly by having mitochondria with discoid cristae, in the absence of superfic ...

s they include the majority of the naked filose amoebae.

Systematics and Phylogeny

Clades and Genera

There are at least 45 credibly described species that are either proved or likely to belong to the order Vampyrellida, falling into 14 genera, which can be grouped into 5 clades: *Leptophryidae Hess, Sausen & Melkonian, 2012 **'' Arachnomyxa'' Hess, 2017 **'' Leptophrys'' Hertwig & Lesser, 1874 **'' Planctomyxa'' Hess, 2017 **''

Platyreta The family Vampyrellidae is a subgroup of the order Aconchulinida (formerly Vampyrellida) within the phylum Cercozoa. Based on molecular sequence data, the family currently comprises the genus '' Vampyrella'', and maybe several other vampyrelli ...

'' Cavalier-Smith & Bass, 2008 **'' Theratromyxa'' Zwillenberg, 1952 **'' Vernalophrys'' Gong et al. 2015 *Placopodidae Jahn, 1928 = Hyalodiscidae Poche, 1913 **'' Placopus'' Schulze, 1875 = ''Hyalodiscus'' Hertwig & Lesser, 1874 *Sericomyxidae More, Simpson & Hess, 2021 **'' Sericomyxa'' More et al. 2021 *''Thalassomyxa'' clade **'' Thalassomyxa'' Grell, 1985 *Vampyrellidae Zopf, 1885 **''

'' Cienkowski, 1865 *Vampyrellida ''incertae sedis'' **'' Arachnula'' Cienkowski, 1876 (potential

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...

with ''Thalassomyxa'', Leptophryidae) **'' Asterocaelum'' Canter, 1973 (? Leptophryidae) **'' Lateromyxa'' Hülsmann, 1993 **'' Monadopsis'' Klein, 1882 *Genera with uncertain phylogenetic affinity **'' Gobiella'' Cienkowski, 1881 (putative amoeboid

heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which a ...

alga, ≈'' Chlamydomyxa'') **'' Vampyrellidium'' Zopf, 1885 (

amoebae)Patterson, D.J., Surek, B. & Melkonian, M. 1987. The ultrastructure of Vampyrellidium perforans Surek & Melkonian and its taxonomic position among the naked filose amoebae. J. Protozool., 34: 63-67. **'' Vampyrelloides'' Schepotieff, 1912 = ''Protogenes'' Trichense, 1885 **'' Vampyrina'' Frenzel, 1893

Phylogenetic Tree

References

External links

* *http://starcentral.mbl.edu/microscope/portal.php?pagetitle=assetfactsheet&imageid=932 *http://tolweb.org/tree?group=The_other_protists&contgroup=Eukaryotes {{Taxonbar, from=Q917169 Aconchulinida Cercozoa families Taxa named by Friedrich Wilhelm Zopf