Audouinella is a widespread genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of red algae

Red algae

The red algae are one of the oldest groups of eukaryotic algae, and also one of the largest, with about 5,000–6,000 species  of mostly multicellular, marine algae, including many notable seaweeds...

, found in marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 and freshwater

Freshwater

Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

. Grows as small tufts of red, brown, or black hairlike filaments on any solid surface - most dramatically on the edges of slow-growing leaves. Often tolerant of high levels of pollution

Pollution

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

, acidity, and thrives on dissolved phosphate

Phosphate

A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...

 and nitrate

Nitrate

The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...

s. Reproduces via spore

Spore

In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

s.

The form known as Black Brush Algae is a particular nuisance in aquaria

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

 as few fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, even those widely promoted as algivores

Algae eater

Algae eater is a common name for many bottom-dwelling fish that feed on algae. Algae eaters are important for the fishkeeping hobby and many are commonly kept by hobbyists.Some of the common and most popular freshwater algae eaters include:...

, will eat it.

In natural ecosystems, this genus that infested aquariums is found in unpolluted lotic systems.

It has been tested for germination and new growth using NO₃ and PO₄ fertilizers and such results came out negative for a decade's worth of observations. It has been shown to be inducible by limiting and varying the CO₂ concentration in planted aquariums. While other possible inducement mechanisms may exists, this is the most consistent and has been shown in many test by aquarists.

External links

• http://www.vliz.be/cgi-bin/aphi2web.exe?action=taxon&id=21823 contains more taxonomic information on this alga.