''Audouinella'', also known as black algae,
is a widespread
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
red algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...
, found in
marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
Ocean
* Maritime (disambiguation)
* Marine art
* Marine biology
* Marine debris
* Marine habitats
* Marine life
* Marine pollution
Military
* ...
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. Although the term specifically excludes seawater and brackish water, it does include ...
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
Algae eater or algivore is a common name for any bottom-dwelling or filter-feeding aquatic animal species that specialize in feeding on algae and phytoplanktons. Algae eaters are important for the fishkeeping hobby and many are commonly kept by ...
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
Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms were ...
are composed of uniaxial filaments, the ends of which often contain elongate hairs.spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
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 adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
, acidity
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
, and thrive on dissolved phosphate
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 orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
and nitrate
Nitrate is a polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...
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 (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
* Red algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...
* Algae eater
Algae eater or algivore is a common name for any bottom-dwelling or filter-feeding aquatic animal species that specialize in feeding on algae and phytoplanktons. Algae eaters are important for the fishkeeping hobby and many are commonly kept by ...
References
External links
* – taxonomic information on this alga.
*
{{Taxonbar, from=Q1761163
Red algae genera
Acrochaetiales