Tropidophoxinellus alburnoides is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of fish in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Cyprinidae. It is found in Portugal

Portugal

Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

 and Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

. Its natural habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

s are river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s and intermittent rivers. It may be threatened by habitat loss.

Tropidophoxinellus alburnoides is a highly peculiar fish in regard to its evolution and reproduction. It has been derived from hybridisation

Hybridisation

Hybridisation or hybridization may refer to:*The process of combining different varieties or species of organisms to create a hybrid *Nucleic acid hybridisation, the process of joining two complementary strands of DNA...

 between females of Squalius pyrenaicus

Squalius pyrenaicus

Squalius pyrenaicus is a species of freshwater fish in the family Cyprinidae. It is found in Portugal and Spain.Its natural habitats are rivers, intermittent rivers, and water storage areas. It is becoming rare due to habitat loss....

and males of another, unknown cyprinid species, and maintains the genome

Genome

In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

s of both parental species. Tropidophoxinellus alburnoides may have various numbers of these genomes (polyploidy

Polyploidy

Polyploid is a term used to describe cells and organisms containing more than two paired sets of chromosomes. Most eukaryotic species are diploid, meaning they have two sets of chromosomes — one set inherited from each parent. However polyploidy is found in some organisms and is especially common...

), and may use different reproductive modes to pass them on to the offspring, including asexual reproduction

Asexual reproduction

Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...

, normal meiosis

Meiosis

Meiosis is a special type of cell division necessary for sexual reproduction. The cells produced by meiosis are gametes or spores. The animals' gametes are called sperm and egg cells....

 and hybridogenesis.

Sources

• Crivelli, A.J. (2006) Iberocypris alburnoides. 2010. IUCN Red List of Threatened Species. Version 2010. Downloaded on 19 June 2010.
• Pala I, Schartl M, Thorsteinsdóttir S, Coelho MM (2009) Sex Determination in the Squalius alburnoides Complex: An Initial Characterization of Sex Cascade Elements in the Context of a Hybrid Polyploid Genome PLoS ONE
  PLoS ONE
  PLoS ONE is an open access peer-reviewed scientific journal published by the Public Library of Science since 2006. It covers primary research from any discipline within science and medicine. All submissions go through an internal and external pre-publication peer review but are not excluded on the...
  
  4(7): e6401. doi:10.1371/journal.pone.0006401