''Hafniomonas'' 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 ...

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 ...

in the family

Dunaliellaceae Dunaliellaceae is a family of algae in the order Chlamydomonadales. It is widespread in freshwater and saline environments worldwide, less so in marine waters. Members of the family Dunaliellaceae are single-celled, flagellate algae. They are of ...

.See the

NCBI The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is loca ...

br>webpage on Hafniomonas
Data extracted from the It is found in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

. ''Hafniomonas'' is a unicellular, flagellate alga. Cells are elongate, ovoid, pyriform or cylindrical or globose-cordate; they are typically somewhat four-sided in cross section, with the anterior end bearing four longitudinal, rounded ridges. At the center of the anterior end emerge 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 ...

, sometimes with a small papilla. The cell contains a single nucleus, two

contractile vacuole A contractile vacuole (CV) is a sub-cellular structure (organelle) involved in osmoregulation. It is found predominantly in protists, including unicellular algae. It was previously known as pulsatile or pulsating vacuole. Overview The contrac ...

s, and one cup-shaped, parietal

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 ...

and a distinct stigma and

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 ...

. The chloroplast may be perforate, separated into segments. Asexual reproduction occurs via cell division, and sometimes cells form

cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubb ...

s or palmelloid stages. Sexual reproduction is unknown. ''Hafniomonas'' consists of species that were formerly classified within ''

Pyramimonas ''Pyramimonas'' is a genus of green algae in the order Pyramimonadales. Phototropic euglenids inherited their plastids from a close relative of ''Pyramimonas'' which was an endosymbiont inside phagotrophic eukaryovorous euglenids. References

''. Unlike ''

'', ''Hafniomonas'' lacks cell walls and a covering of scales. ''Hafniomonas'' has chloroplasts with are not markedly lobed, unlike ''Pyramimonas'' which has chloroplasts which are markedly lobed into four, eight or 12 lobes in the anterior. Within ''Hafniomonas'', species are distinguished based on the position of the pyrenoid, form of the chloroplast and stigma, and shape and size of cells.

References

Chlamydomonadales genera Chlamydomonadales Freshwater algae {{Chlorophyceae-stub