| Imasa | |
|---|---|
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Malawimonada |
| Phylum: | Malawimonada |
| Class: | Malawimonadea |
| Order: | Malawimonadida |
| Family: | Imasidae Heiss, Simpson & Kim 2020 |
| Genus: | Imasa Heiss, Simpson & Kim 2020 |
| Species: | I. heleensis |
| Binomial name | |
| Imasa heleensis Heiss, Simpson & Kim 2020 | |
| Type strain | |
| AMNH_IZC 00343331 | |
Imasa is agenus ofmarineflagellates containing the singlespeciesImasa heleensis, discovered in 2020 in theSolomon Islands.[1] It is the first marine member of abasal group ofeukaryotes known asMalawimonadida.[2] It is the only member of the familyImasidae.[1]
Thegenus nameImasa is the name of the research vessel used to obtain the cells ofImasa heleensis that were isolated. It refers to the pause taken by acrocodile between its emergence from the water and its attack. This pause between actions is resembled by the movement of the anteriorflagellum ofImasa, which often appears to pause near the point between the extension and recovery strokes. Thespeciesepithetheleensis refers to ‘Hele’, which is the name of the isles containing the collection site ofImasa heleensis atSolomon Islands. As with the genus name, it is common among the indigenous languages of the region.[1]
Imasa heleensis was isolated from amarine shallowlagoon. Like the other two accepted species of malawimonadsGefionella okellyi andMalawimonas jakobiformis, which were isolated fromsoil andfreshwater respectively,Imasa isecologically associated with a particulate substrate. However, its ability to generate a protrusion from the posterior end of thecell is unusually long (~3 μm when suspended, ~15-20 μm when adhered to the substrate) compared to its terrestrial counterparts (~1 μm inG. okellyi). As for the ventral groove, it only runs the anterior half of the cell inImasa heleensis, while in the rest of malawimonads it runs the whole length of the cell.[1]
An additional characteristic ofImasa is its shorterflagellar vane compared to other malawimonads. The vanes end abruptly in a steeper angle with theaxoneme, which may result in the generation of fluid movement from a shorter length of the posteriorflagellum.[1]
Themitochondrial genome ofImasa heleensis is similar to other malawimonads, except for the presence of thesdh3 gene, which is absent in any other known malawimonad.[1]
Imasa is the first marinemalawimonadtaxon to be described. According tophylogenetic analyses based onSSU rRNA genes, it is thesister taxon to the rest of malawimonads, theGefionella+Malawimonasclade. Because of this,Imasa was placed in a separate family, Imasidae, while the familyMalawimonadidae was reserved for the other two genera.[1]
| Malawimonadida |
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