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
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
Spondylomoraceae
Spondylomoraceae is a family of algae in the order Chlamydomonadales.See the NCBIbr>webpage on Spondylomoraceae Data extracted from the It consists of various freshwater, microscopic algae.
Members of the Spondylomoraceae are coenobial flagel ...
. It 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 ...
, found in
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...
rich in organic matter.
''Pyrobotrys'' consists of colonies (termed coenobia) of four, eight or 16 arranged in two or four tiers, with a star- or mulberry-like shape. Cells are spherical, ovoid, ellipsoid, or pear-shaped. Each has two equal
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 ...
, two contractile vacuoles at the base of the flagella, and a large cup-shaped
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 ...
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.
''Pyrobotrys'' reproduces both asexually and sexually. In asexual reproduction, each cell of the colony divides to form a daughter colony. In sexual reproduction, cells divide into 4, 8, 16, or 32 biflagellate
isogamete
Isogamy is a form of sexual reproduction that involves gametes of the same morphology (indistinguishable in shape and size), and is found in most unicellular eukaryotes. Because both gametes look alike, they generally cannot be classified as ma ...
s, which fuse to form planozygotes, with four flagella. Upon germination, the planozygotes divide into four "gone cells" which then develop into new colonies.
Species of ''Pyrobotrys'' are distinguished based on the shape of the cells, number of cells in a colony, presence or absence of a stigma, and shape of the planozygote.