''Chaetophora'' 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

Chaetophoraceae Chaetophoraceae is a family (biology), family of green algae in the order Chaetophorales. Members of the family are variously semi-terrestrial to aquatic in habitat, and consist of branched filaments in two parts, a prostrate system of filaments ...

. 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 ...

. It is found on

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s or other submerged surfaces in still or moving

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 ...

. Many species seem to prefer colder waters, being more abundant during the winter and spring months.

Description

''Chaetophora'' consists of tuberculose or arbuscular thalli of a mucilaginous or cartilaginous texture. The prostrate part of the thallus is little developed, while the erect part consists of uniseriate filaments, which are highly branched and intertwined; each filament ends in a blunt point or tapers to a long, multicellular hair. Cells contain a single 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 ...

with one to several

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. Both

asexual Asexual or Asexuals may refer to: *Asexual reproduction **Asexual reproduction in starfish *Asexuality, the lack of sexual attraction to anyone or lack of interest in or desire for sexual activity. **Gray asexuality, the spectrum between asexualit ...

and

sexual reproduction Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...

are known. In asexual reproduction, zoospores are quadriflagellate (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 ...

); sexual reproduction is

isogamous 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 ...

with biflagellate (2-flagellate) gametes. Both are produced in peripheral cells. ''Chaetophora'' can also produce

akinete An akinete is an enveloped, thick-walled, non-motile, dormant cell (biology), cell formed by both cyanobacteria and algae. Cyanobacterial akinetes are mainly formed by filamentous, heterocyst-forming members under the order Nostocales and Stigone ...

s in the peripheral cells, which are brown in color.

Taxonomy

The genus ''Chaetophora'' is problematic, since

species delimitation A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and a ...

has traditionally relied on unreliable characteristics such as the general shape of the filaments and cells and mucilage. Additionally, prior to 2019, the genus was

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

. The similar genus '' Chaetophoropsis'' was split off from ''Chaetophora'' ''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

'' in 2019 to include species that form globose thalli.

References

Chaetophorales genera Chaetophoraceae Freshwater algae {{Chlorophyceae-stub