''Treubaria'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of microscopic

green algae The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...

, the sole genus in the family Treubariaceae. ''Treubaria'' is found in freshwater habitats and has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

. The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by Charles Jean Bernard in Protococ. Desmid. Eau Douce 5–6, 12, 169 in 1908. The genus name of ''Treubaria'' is in honour of

Melchior Treub Melchior Treub (26 December 1851 – 3 October 1910) was a Dutch botanist. He worked at the Bogor Botanical Gardens in Buitenzorg on the island of Java, south of Batavia, Dutch East Indies, gaining attention for his work on tropical flora. He a ...

(1851–1910), who was a Dutch

botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

. He worked at the

Bogor Botanical Gardens The Bogor Botanical Gardens () is a botanical garden located in Bogor, Indonesia, 60 km south of central Jakarta. It is currently operated by the National Research and Innovation Agency. The garden is located in the city center and adjoin the ...

Buitenzorg Bogor City (), or Bogor (, ), is a landlocked city in the West Java, Indonesia. Located around south of the national capital of Jakarta, Bogor is the 6th largest city in the Jakarta metropolitan area and the 14th overall nationwide.

on the island of

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

, south of

Batavia, Dutch East Indies Batavia was the capital of the Dutch East Indies. The area corresponds to present-day Jakarta, Indonesia. Batavia can refer to the city proper or its suburbs and hinterland, the , which included the much larger area of the Residency of Batavia ...

, gaining renown for his work on tropical flora.

Description

''Treubaria'' consists of single cells that are

planktonic Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they pro ...

. The

protoplast Protoplast (), is a biology, biological term coined by Johannes von Hanstein, Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterium, bacterial, or f ...

is 5–22 μm in diameter, spherical to multi-lobed, with 3–4 (sometimes up to 20) hollow, conical or tubular spines (up to 83 μm long) radiating from the cells. Cells are uninucleate when young, but have up to four or five nuclei when mature. They have one

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

when young; chloroplasts have one (or multiple)

pyrenoid Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''An ...

s. ''Treubaria'' reproduces asexually; sexual reproduction has not been observed in ''Treubaria''. Asexual reproduction typically occurs through the formation of

autospore Autospores are a type of spores that are produced by algae to enable asexual reproduction and spread. They are non-motile and non-Flagellated cell, flagellated Aplanospore, aplanospores that are generated within a parent cell and have the same sha ...

s; four autospores are produced per cell. One species is known to produce zoospsores. Two, four, or eight zoospores are produced per cell, each with four

flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

Classification

The classification of ''Treubaria'' is currently unclear. Currently, the taxonomy of

is in flux because morphological characteristics do not align with

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

relationships. Phylogenetically, ''Treubaria'' forms a close relationship with ''

Cylindrocapsa ''Cylindrocapsa'' is a genus of green algae, specifically of the Chlorophyceae. It is commonly found in freshwater habitats. Virus-like particles have been found in a strain of one species, '' Cylindrocapsa geminella''. Description ''Cylindrocap ...

'', ''

Elakatothrix ''Elakatothrix'' is a genus of green algae in the class Klebsormidiophyceae. Etymology Genus name ''Elakatothrix'' is composed of elakato- prefix, "spindle", and –thrix suffix, "thread", literally "spindle thread",Phycokey-Elakatothrix read ...

'', and ''

Trochiscia ''Trochiscia'' is a genus of green algae in the family Oocystaceae. It is found in the plankton of freshwater habitats. The name ''Trochiscia'' was used in 1834 by Friedrich Traugott Kützing. Description ''Trochiscia'' consists of solitary, sph ...

''. All four genera share

ultrastructural Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a c ...

features such as pyrenoids where the matrix is penetrated by cytoplasmic invaginations, and ''Cylindrocapsa'' produces quadriflagellate zoospores. However, the genera share litle else in common, making a coherent classification difficult.

Species

As accepted by

WoRMS The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

; *''

Treubaria crassicornuta ''Treubaria'' is a genus of microscopic green algae, the sole genus in the family Treubariaceae. ''Treubaria'' is found in freshwater habitats and has a cosmopolitan distribution. The genus was circumscribed by Charles Jean Bernard in Protococ. ...

'' *''

Treubaria crassispina ''Treubaria'' is a genus of microscopic green algae, the sole genus in the family Treubariaceae. ''Treubaria'' is found in freshwater habitats and has a cosmopolitan distribution. The genus was circumscription (taxonomy), circumscribed by Charle ...

'' *''

Treubaria planctonica ''Treubaria'' is a genus of microscopic green algae, the sole genus in the family Treubariaceae. ''Treubaria'' is found in freshwater habitats and has a cosmopolitan distribution. The genus was circumscribed by Charles Jean Bernard in Protococ. ...

'' *''

Treubaria quadrispina ''Treubaria'' is a genus of microscopic green algae, the sole genus in the family Treubariaceae. ''Treubaria'' is found in freshwater habitats and has a cosmopolitan distribution. The genus was circumscribed by Charles Jean Bernard in Protococ. ...

'' *'' Treubaria schmidlei'' *''

Treubaria setigera ''Treubaria'' is a genus of microscopic green algae, the sole genus in the family Treubariaceae. ''Treubaria'' is found in freshwater habitats and has a cosmopolitan distribution. The genus was circumscribed by Charles Jean Bernard in Protococ. ...

'' *'' Treubaria triappendiculata'' *'' Treubaria umbrina'' Former species; * ''T. euryacantha'' accepted as ''Treubaria triappendiculata'' * ''T. limnetica'' accepted as ''Treubaria schmidlei'' * ''T. varia'' accepted as ''Treubaria schmidlei'' Species of ''Treubaria'' are identified based on morphological characteristics such as the shape of the protoplast and the shape and number of spines. However, all species are very polymorphic and require further revisions.

References

Sphaeropleales genera Sphaeropleales Freshwater algae {{Chlorophyceae-stub