| Mayorella marianaensis | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Phylum: | Amoebozoa |
| Class: | Discosea |
| Order: | Dermamoebida |
| Genus: | Mayorella |
| Species: | M. marianaensis |
| Binomial name | |
| Mayorella marianaensis Lei, Chen, Chen & Liang 2023 [1] | |
Mayorella marianaensis is a species of amoebozoan protist discovered in 2023 in Mariana Trench sediments. It belongs to the order Dermamoebida, [1] a group of naked amoebae with a thick glycocalyx. [2]
Cells of Mayorella marianaensis were isolated and cultivated from deep-sea sediments at a depth of 3,144 meters in the vicinity of the Mariana Trench, in the Pacific Ocean. The culture was characterized as a new Mayorella species through morphological and phylogenetic analyses using SSU rRNA genes. The results were published by Xiaoli Lei, Xiaojuan Chen, Jianming Chen and Chen Liang in the journal Protist in June 2023. [1]
Mayorella marianaensis locomotive cells have an average width of 74 µm and length of 28 µm. In addition there are three floating forms identified. The most common floating form is an irregular sphere of 25–47 µm in diameter. The second floating form has between 18 and 25 very small pseudopodia (around 9–30 µm in length), while the third has about 6 to 9 thin and radiating pseudopodia (around 25–125 µm in length). The cell coat (or cuticle) outside of the plasma membrane is around 190 to 290 nm thick and consists of two layers: an outer layer, loosely arranged, with its surface covered with hairs called glycostyles; and an inner layer, closely arranged in stripes. [1]
The actinophryids are an order of heliozoa, a polyphyletic array of stramenopiles, having a close relationship with pedinellids and Ciliophrys. They are common in fresh water and occasionally found in marine and soil habitats. Actinophryids are unicellular and roughly spherical in shape, with many axopodia that radiate outward from the cell body. Axopodia are a type of pseudopodia that are supported by hundreds of microtubules arranged in interlocking spirals and forming a needle-like internal structure or axoneme. Small granules, extrusomes, that lie under the membrane of the body and axopodia capture flagellates, ciliates and small metazoa that make contact with the arms.
Oceanic trenches are prominent, long, narrow topographic depressions of the ocean floor. They are typically 50 to 100 kilometers wide and 3 to 4 km below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about 50,000 km (31,000 mi) of oceanic trenches worldwide, mostly around the Pacific Ocean, but also in the eastern Indian Ocean and a few other locations. The greatest ocean depth measured is in the Challenger Deep of the Mariana Trench, at a depth of 10,920 m (35,830 ft) below sea level.
Foraminifera are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell of diverse forms and materials. Tests of chitin are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment, while a smaller number float in the water column at various depths, which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA.
Gromia is a genus of protists, closely related to foraminifera, which inhabit marine and freshwater environments. It is the only genus of the family Gromiidae. Gromia are ameboid, producing filose pseudopodia that extend out from the cell's proteinaceous test through a gap enclosed by the cell's oral capsule. The test, a shell made up of protein that encloses the cytoplasm, is made up of several layers of membrane, which resemble honeycombs in shape — a defining character of this genus.
The hadal zone, also known as the hadopelagic zone, is the deepest region of the ocean, lying within oceanic trenches. The hadal zone ranges from around 6 to 11 km below sea level, and exists in long, narrow, topographic V-shaped depressions.
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 transparent layer called hyaloplasm forms at the leading edge of the cell. In some discoseans, short "subpseudopodia" may be extended from this hyaloplasm, but the granular contents of the cell do not flow into these, as in true pseudopodia. Discosean amoebae lack hard shells, but some, like Cochliopodium and Korotnevella secrete intricate organic scales which may cover the upper (dorsal) surface of the cell. No species have flagella or flagellated stages of life.
Mayorella is a genus of small amoeboid protists in the phylum Amoebozoa. The genus consists of amoebae that exhibit pseudopodia and feed on a variety of organisms through phagocytosis, making them an important group in microbial ecology across most environments worldwide. Mayorella species have been found in soil, freshwater and marine environments.
Massisteria is a genus of Cercozoa. They are naked protists with a central cell body from which several delicately thin and stiff pseudopodia extend, each one bearing a small number of granules. Their pseudopodia remain adhered to the substrate, as is typical among leucodictyids. The cell body has two flagella that, during feeding, are held in place.
Thaumatomastix is a protist genus of the order Thaumatomonadida, within the phylum Cercozoa and the class Imbricatea. Its species are aquatic, feeding on algae and appearing in waters of a wide range of temperatures and salinities, and are 15-50 micrometers long. They can interchange between flagellated and amoeboid forms, and are notable for being covered in both spiny and flattened siliceous scales.
Katabia is a genus of soil-dwelling heterotrophic flagellate cercozoans containing the single species Katabia gromovi, and the only member of family Katabiidae.
Miliamellus is a genus of Cenozoic benthic foraminifera with tests made of imperforate opaline silica. It is the only genus in the order Silicoloculinida and the family Silicoloculinidae. It is sometimes referred to by the junior synonym Silicoloculina.
Reticulomyxa is a monospecific genus of freshwater foraminiferans. The type species is the unicellular Reticulomyxa filosa. It is found in freshwater environments as well as moist environments, like decomposing matter and damp soils. The heterotrophic naked foraminiferan can feed on microbes as well has larger organisms and is able to be sustained in culture by supplemented nutrients such as wheat germ and oats. The large, multinucleate foraminferan is characteristic for its lack of test and named for the network of connecting pseudopodia surrounding its central body mass. The organism has unique bidirectional cytoplasmic streaming throughout the anastomosing pseudopodia that is some of the fastest reported organelle transport observed. Reticulomyxa was first described in 1949 and is commonly used as a model organism for the unique transport of organelles throughout the cytoplasm of pseudopodia by cytoskeletal mechanisms. Only asexual reproduction of this genus has been observed in culture, but the genome possesses genes related to meiosis suggesting it is capable of sexually reproductive life stages.
Platysulcus is an eukaryotic microorganism that was recently discovered to be the earliest diverging lineage of the Heterokont phylogenetic tree. It is the only member of the family Platysulcidae, order Platysulcida and class Platysulcea, of uncertain taxonomic position within the phylum Bigyra. It contains the only species P. tardus.
Occultammina is a genus of xenophyophorean foraminifera known from the Atlantic and Pacific oceans. It is notable for being the first known infaunal xenophyophore as well as for being a possible identity for the enigmatic trace fossil Paleodictyon.
Foraminiferal tests are the tests of Foraminifera.
Tetrahelia is a genus of four-ciliated protists belonging to the Endohelea, a group of heterotrophic eukaryotes previously considered heliozoa. It is the only genus in the family Tetraheliidae and order Axomonadida. It is a monotypic genus, containing the sole species Tetrahelia pterbica, previously classified as Tetradimorpha.
Mesofila is a genus of freshwater heterotrophic protists of the phylum Cercozoa. It is the only genus in the family Mesofilidae. It is a monotypic genus, with the sole species M. limnetica.
Massisteria marina is a species of small marine phagotrophic protists that normally feed on bacteria. Individuals live associated with sediment particles and suspended detritus in litoral or marine waters. It is found at marine sites all around the world. Its predominantly sedentary lifestyle was a discovery that challenged the concept of bacterivorous protists as constantly active hunters, and its permanent association with detritus particles is uncommon among flagellates.
Minimassisteria is a marine bacterivorous genus of protists with only one species, M. diva, that presents three different lifestyle forms. It has a widespread geographic distribution. It is an amoeboflagellate most closely related to Massisteria, and together comprise the family Massisteriidae.
Viridiraptoridae, previously known as clade X, is a clade of heterotrophic protists in the phylum Cercozoa. They're a family of glissomonads, a group containing a vast, mostly undescribed diversity of soil and freshwater organisms.