''Brachionus plicatilis'' is a

euryhaline Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the molly (''Poecilia sphenops'') which can live in fresh water, brackish water, or salt water. The green crab (''Carcinus maenas'') is an e ...

(tolerate a wide range of

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

)

rotifer The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Brachionidae Brachionidae is a family of rotifers belonging to the order Ploima. Genera: * '' Anuraeopsis'' Lauterborn, 1900 * ''Brachionus ''Brachionus'' is a genus of planktonic rotifers occurring in freshwater, alkaline and brackish water. Species Sp ...

'', and is possibly the only commercially important rotifer, being raised in the

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

industry as food for fish larvae. It has a broad distribution in salt lakes around the world and has become a model system for studies in

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

and

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

Reproduction

''Brachionus'' species can normally reproduce asexually and sexually (cyclical parthenogenesis). Sexual reproduction (termed Mixis) is usually induced when population density increases. Mixis in Brachionus plicatilis has been shown to be induced by a density-dependent chemical cue.

Genome size

Haploid '1C' genome sizes in the ''Brachionus plicatilis'' species complex range at least from 0.056 to 0.416 pg. The complete mitochondrial genome of B. plicatilis sensu stricto NH1L has been sequenced.

Cryptic species complex

Brachionus plicatilis strains have long been divided into ‘L-’ and ‘S-type’ forms. However, studies on morphology, karyotype, genetics and reproductive behaviour revealed that these types seem to be different species (B. plicatilis and B. rotundiformis). DNA sequencing studies in 2002 revealed ''Brachionus plicatilis'' to be a

cryptic species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

comprising approximately 10 separate species, each of which has been diverging for several million years. A recent study identified 22 potential different species within the Plicatilis species complex.
The species, rather than the complex, is now usually referred to as ''Brachionus plicatilis'' s. s. (sensu stricto).
The species complex can be divided into 3 major clades (clade L = larger body and genome sizes e.g. B. plicatilis s.s., clade SM = medium body and genome sizes e.g. B. 'Almenara', clade SS = small body and genome size e.g. B. rotundiformis). http://www.biomedcentral.com/1471-2148/11/90/figure/F1 ;List of the 22 suspected species of the B. plicatilis cryptic species complex Species names and clade in () Diversity of the rotifer Brachionus plicatilis species complex (Rotifera: Monogononta) in Iran through integrative taxonomy Reza Malekzadeh-Viayeh1,*, Razieh Pak-Tarmani1, Nasim Rostamkhani2 and Diego Fontaneto3 Article first published online: 7 JAN 2014 DOI: 10.1111/zoj.12106 # * B01: B. 'Tiscar', S.? (B) # * B02: unnamed, S. 6 (B) # * B03: B. 'Persia', S. ? (B) # * B04: B. 'Harvey', S. 14 (B) # * B05: B. ibericus, S. 10 (B) # * B06: B. Almenara (or MEG-2012), S. 9 (B) # * B07: B. 'Towerinniensis, S. 7 (B) # * B08: B. 'Coyrecupiensis', S. 8 (B) # * B09: B. 'Cayman' (or B. koreanus), S. 5 (B) # * B10: B. 'Cayman' (or B. koreanus), S. 5 (B) # * B11: B. 'Austria', S. 4 (A) # * B12: B. Nevada, S. 3 (A) # * B13: B. Nevada, S. 3 (A) # * B14: B. Nevada, S. 3 (A) # * B15: B. plicatilis s.s., S. 1 (A) # * B16: B. manjavacas, S. 2 (A) # * B17: unnamed, S. 12 (C) # * B18: unnamed, S. 12 (C) # * B19: unnamed, S. 12 (C) # * B20: B. rotundiformis, S. 11 (C) # * B21: unnamed, S. ? (C) # * B22: B. 'Lost', S. 13 (C) #

References

{{Taxonbar, from=Q2488359 Brachionidae Laboratory animals Animals described in 1786