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 euk ...

. Based on molecular sequence data, the family currently comprises the genus '' Vampyrella'', and maybe several other vampyrellid amoebae (e.g. ''Gobiella''). The cells are naked and characterised by radiating, filose pseudopodia (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 form, with an obvious distinction between the clear periphery and pseudopods and the greenish interior. In this form it finds its way into algae cells and feeds on their interiors. At least one genus, Theratromyxa, also feeds on soil nematodes. A few other vampyrellids are parasitic on

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 of

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 cristae. 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 **'' Vampyrella'' Cienkowski, 1865 *Vampyrellida ''incertae sedis'' **'' Arachnula'' Cienkowski, 1876 (potential synonym with ''Thalassomyxa'', Leptophryidae) **'' Asterocaelum'' Canter, 1973 (? Leptophryidae) **'' Lateromyxa'' Hülsmann, 1993 **'' Monadopsis'' Klein, 1882 *Genera with uncertain phylogenetic affinity **'' Gobiella'' Cienkowski, 1881 (putative amoeboid heterokont 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