''Dracoamoeba'' is a free-living genus of

discosea Discosea is a class of Amoebozoa, consisting of naked amoebae with a flattened, discoid body shape. Members of the group do not produce tubular or subcylindrical pseudopodia, like amoebae of the class Tubulinea. When a discosean is in motion, a ...

n amoebae in the family

Acanthamoebidae Acanthamoebidae is a family of single-celled eukaryotes within the group Amoebozoa. It gets its name from '' Acanthamoeba'', its best-known member. However, it also includes other species, such as '' Comandonia operculata'' and '' Protacanthamoe ...

containing the sole

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

''Dracoamoeba jomungandri'', discovered in 2016 in moist muddy soil close to the ocean shore at

Chincoteague, Virginia Chincoteague ( or ) is a town in Accomack County, Virginia, United States. The town includes the whole of Chincoteague Island and an area of adjacent water. The population was 3,344 at the 2020 census. The town is a tourist gateway to the Ch ...

(United States).

Etymology

The generic name ''Dracoamoeba'' comes from the Latin “Draco”, meaning “

dragon A dragon is a Magic (supernatural), magical legendary creature that appears in the folklore of multiple cultures worldwide. Beliefs about dragons vary considerably through regions, but European dragon, dragons in Western cultures since the Hi ...

”, which is what the forms of this amoeba resemble. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''jomungandri'' comes from

Jörmungandr In Norse mythology, Jörmungandr (, see Etymology), also known as the Midgard Serpent or World Serpent (, "worm of Midgard"), is an unfathomably large and monstrous sea serpent or worm who dwells in the world sea, encircling the Earth ( Midga ...

, the oceanic

sea serpent A sea serpent is a type of sea monster described in various mythologies, most notably in Mesopotamian cosmology (Tiamat), Ugaritic cosmology ( Yam, Tannin), biblical cosmology (Leviathan, Rahab), Greek cosmology (Cetus, Echidna, Hydra, Scy ...

norse mythology Norse, Nordic, or Scandinavian mythology, is the body of myths belonging to the North Germanic peoples, stemming from Old Norse religion and continuing after the Christianization of Scandinavia as the Nordic folklore of the modern period. The ...

Morphology

Members of ''Dracoamoeba'' are amoebae with ramose

pseudopodia A pseudopod or pseudopodium (: 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 filaments and ...

capable of forming one

lamellipodium The lamellipodium (: lamellipodia) (from Latin ''lamella'', related to ', "thin sheet", and the Greek radical ''pod-'', "foot") is a cytoskeletal protein actin projection on the leading edge of the cell. It contains a quasi-two-dimensional act ...

with acanthapodial (i.e. tooth-shaped) subpseudopodia.

Pseudopodia A pseudopod or pseudopodium (: 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 filaments and ...

of all forms are made up of hyaloplasm, a

hyaline A hyaline substance is one with a glassy appearance. The word is derived from , and . Histopathology Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellula ...

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 ...

that composes the

, and are used for locomotion and feeding. Their cell body is made of granuloplasm, a granulose

that surrounds the

nucleus Nucleus (: nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleu ...

as opposed to the hyaloplasm. In particular, ''D. jomungandri'' exhibits long, tapering thin ramose pseudopodia from all sides of the main cell body when attached to the surface of a culture flask. In this state, its length ranges from 33 to 87

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

long, with a mean length of 57.6 μm, and its width ranges from 3 to 12 μm, with a mean cell body width of 6.2 μm. Its

are composed of hyaloplasm while the main body of the cell is made of granuloplasm. It does not form uroids, traces left by some amoebae during locomotion. No cysts have been observed from this species. Upon starvation, it will shrivel up and detach from the surface, and can remain suspended in the water column or float to the water surface.

References

{{Taxonbar, from1=Q113827376 Amoebozoa genera Discosea