Brachionus

From Wikipedia, the free encyclopedia
Brachionus
Brachionus calyciflorus
Scientific classification
Kingdom: Animalia
Phylum: Rotifera
Class: Monogononta
Order: Plioma
Family: Brachionidae
Genus: Brachionus
Pallas, 1766
Species

about 30 [1]

Brachionus quadridentatus

Brachionus is a genus of planktonic rotifers occurring in freshwater, alkaline and brackish water.

Species

e.g. Brachionus calyciflorus, Brachionus plicatilis s.s., Brachionus ibericus, Brachionus rotundiformis, Brachionus manjavacas, Brachionus sp. Austria, Brachionus sp. Almenara, Brachionus sp. Tiscar, Brachionus urceolaris, Brachionus sp. Cayman, Brachionus quadridentatus, Brachionus dimidiatus, Brachionus patulus, Brachionus sp. Nevada, Brachionus rubens, Brachionus falcatus, Brachionus havanaensis, Brachionus angularis, Brachionus diversicornis, Brachionus forficula, Brachionus dimidiatus, Brachionus macracanthus, Brachionus caudatus, Brachionus bidentata, Brachionus leydigi

Use

Rotifers such as Brachionus calyciflorus are favored test animals in aquatic toxicology because of their sensitivity to most toxicants. They also are used as model organisms in various other biological fields e.g. due to their interesting reproductive mode in evolutionary ecology. Brachionus spp. are easily reared in large numbers and because of this are used to substitute for wild zooplankton for feeding hatchery reared larval fish. However, the composition of rotifers generally does not satisfy the nutritional requirements of fish larvae,[2] and large amounts of research has been invested in improving the lipid, vitamin and mineral composition of rotifers to better meet the requirements of fish larvae[3][4][5]

Reproduction

Brachionus species can normally reproduce asexually and sexually (cyclical parthenogenesis). Sexual reproduction is usually induced when population density increases. Transitions to obligate parthenogenesis have been described in Brachionus calyciflorus. In this species, obligate parthenogenesis can be inherited by a recessive allele, which leads to loss of sexual reproduction in homozygous offspring.[6]

Genome size

Haploid '1C' genome sizes in Brachionus species range at least from 0.056 to 0.416 pg.[7]

Genome sequencing

The complete mitochondrial genome of B. plicatilis sensu strictu NH1L has been sequenced.[8]

Cryptic species

Brachionus plicatilis has been demonstrated to be a large cryptic species complex[9] and it is likely that the number of species present in this genus greatly exceeds those currently described.

References

  1. ↑ "Brachionus Pallas, 1766". National Institute for Environmental Studies. Retrieved 2007-06-14. 
  2. ↑ HAMRE, K.; SRIVASTAVA, A., RØNNESTAD, I., MANGOR-JENSEN, A., STOSS, J. (2008). "Several micronutrients in the rotifer Brachionus sp. may not fulfil the nutritional requirements of marine fish larvae". Aquaculture Nutrition 14 (1): 51–60. doi:10.1111/j.1365-2095.2007.00504.x. 
  3. ↑ Penglase, S; Hamre, K., Sweetman, J., Nordgreen, A (2011). "A new method to increase and maintain the concentration of selenium in rotifers (Brachionus spp.)". Aquaculture 315 (1-2): 144–153. doi:10.1016/j.aquaculture.2010.09.007. 
  4. ↑ Dhert, Phillippe; Geert Rombautb, Gede Suantikaa, Patrick Sorgeloos (2001). "Advancement of rotifer culture and manipulation techniques in Europe". Aquaculture 200 (1-2): 129–146. doi:10.1016/S0044-8486(01)00697-4. 
  5. ↑ Nordgreen, A; Penglase, S., Hamre, K., (2013). "Increasing the levels of the essential trace elements Se, Zn, Cu and Mn in rotifers (Brachionus plicatilis) used as live feed". Aquaculture. 380-383: 120–129. doi:10.1016/j.aquaculture.2012.11.032. 
  6. ↑ C.-P. Stelzer, J. Schmidt, A. Wiedlroither, and S. Riss (2010). Loss of Sexual Reproduction and Dwarfing in a Small Metazoan. PLoS ONE 5(9): e12854.
  7. ↑ Stelzer, C.P., Riss, S., Stadler, P. (2011) Genome size evolution at the speciation level: The cryptic species complex Brachionus plicatilis (Rotifera) BMC Evolutionary Biology 11: 90.
  8. ↑ Koushirou Suga, David B. Mark Welch, Yukari Tanaka, Yoshitaka Sakakura, and Atsushi Hagiwara (2008). Two Circular Chromosomes of Unequal Copy Number Make Up the Mitochondrial Genome of the Rotifer Brachionus plicatilis Mol Biol Evol (2008) 25(6): 1129-1137
  9. ↑ Gomez, A et al. (2002). "Speciation in ancient species complexes: evidence from the molecular phylogeny of Brachionus plicatilis (Rotifera)". Evolution 56 (7): 1431–1444. PMID 12206243. 

Huang, L. "Effectof Aldrin on Life History Characteristics of Rotifer Brachionus calyciflorus Pallas." Bull Environ Contam Toxicol no5 N 2007


This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.