''Audouinella'', also known as black algae,
is a widespread
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
red algae
Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxon ...
, found in
marine and
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 ...
environments.
[
The form known as "''black brush algae''" (or "''black beard algae''", ''BBA'' for short) is a particular nuisance in aquaria, since most algae eater fish and invertebrates avoid it.]
Description
J.B. Bory de Saint-Vincent named the genus in 1823, in honour of his co-editor in the ''Dictionnaire Classique d'Histoire Naturelle'', J.V. Audouin.
Black algae species are not all black; they grow as small tufts of red, brown, or black hairlike filaments on any solid surface – most dramatically in freshwater, on the edges of slow-growing leaves.[
Its thalli are composed of uniaxial filaments, the ends of which often contain elongate hairs.]spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s, most commonly asexually, while 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 ...
is known in rare cases.[
Black algae are typically tolerant of high levels of ]pollution
Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...
, acidity, and thrive on dissolved phosphate
Phosphates are the naturally occurring form of the element phosphorus.
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...
and nitrate
Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...
s.
In natural ecosystems, the genus that infests aquariums is found in unpolluted lotic systems.
''Audouinella'' growth can be induced in planted aquariums by limiting and varying the concentration.
It has been tested for germination and new growth using fertilizers NO and PO, but results were negative from a decade of observations.
While other possible means of promoting growth may exist, the adjustment of concentration is the most consistent, as shown in practical tests by aquarists.
See also
* Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
* Red algae
Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxon ...
* Algae eater
References
External links
* – taxonomic information on this alga.
*
{{Authority control
Red algae genera
Acrochaetiales