Nucleariida is a group of amoebae with

filose Filose can refer to a few things: *Filose, describing members of the Filosa subphylum of Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead ...

pseudopods 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 ...

, known mostly from soils and freshwater. They are distinguished from the superficially similar vampyrellids mainly by having

mitochondria A mitochondrion (; ) is an organelle found in the Cell (biology), cells of most Eukaryotes, such as animals, plants and Fungus, fungi. Mitochondria have a double lipid bilayer, membrane structure and use aerobic respiration to generate adenosi ...

with discoid

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, in the absence of superficial granules, and in the way they consume food.

Classification

Molecular studies indicate that nucleariids are closely related to fungi. and more distantly to the lineage that gave rise to choanoflagellates and metazoa opisthokonts, the group which includes animals, fungi. Some use a broad definition of Opisthokonta to include all of these organisms with flattened mitochondrial cristae. The genera ''

Rabdiophrys ''Rabdiophrys'' is a genus of amoeboid rhizarians. It has 19 species, including the species ''Rabdiophrys anulifera''. It was placed before in Nucleariida Nucleariida is a group of amoebae with filose pseudopods, known mostly from soils an ...

'', ''

Pinaciophora ''Pinaciophora'' is an amoeboid genus of Heliozoa of uncertain affinity, previously classified as Rhizaria The Rhizaria are an ill-defined but species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and th ...

'', and ''

Pompholyxophrys ''Pompholyxophrys'' is a genus of Opisthokonta. It includes the species ''Pompholyxophrys punicea''. References Holomycota {{Opisthokont-stub ...

'', freshwater forms with hollow siliceous scales or spines, were included in Nucleariida by some. This was disputed by Smith and Chao who placed them in the Rhizaria. Their affinity with the nucleariids has been confirmed. Historically, nucleariids were included among the heliozoa as the Rotosphaerida because both they and heliozoa had ropunded bodies and radiating pseudopodia. According to a 2009 paper, ''

Fonticula ''Fonticula'' is a genus of cellular slime mold which forms a fruiting body in a volcano shape. As long ago as 1979 it has been known to not have a close relationship with either the Dictyosteliida or the Acrasidae, the two well-established gro ...

'', a cellular slime mold, is an opisthokont and more closely related to ''Nuclearia'' than to fungi.

Characteristics

Nucleariids (''

Nuclearia ''Nuclearia'' is a 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 c ...

'' and ''

Micronuclearia ''Micronuclearia'' is a genus of free-living protozoa. While originally thought to be a nucleariid Nucleariida is a group of amoebae with filose pseudopods, known mostly from soils and freshwater. They are distinguished from the superficially ...

'') are usually small, up to about 50 μm in size.

References

{{Taxonbar, from1=Q1048747, from2=Q13403500 * Opisthokont orders