The red-tailed silverside, or zona (''Bedotia geayi'') is a species of

Madagascar rainbowfish Bedotiinae are a subfamily of the rainbowfish family Melanotaeniidae, commonly known as the Madagascar rainbowfish, Madagascan rainbowfish, or Malagasy rainbowfish due to their endemism to Madagascar. It includes two genera, ''Bedotia'' and ''Rhe ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Mananjary River The Mananjary River is located in southern Madagascar, in the region of Vatovavy. It drains to the eastern coast, into the Indian ocean. It serves as the southern edge of the territory known as Betsimisaraka.Helen Chapin Metz, ed., Madagascar: ...

drainage in

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

and

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

. It has often been confused with the related '' B. madagascariensis'', which is common in the aquarium trade.SeriouslyFish:
Bedotia madagascarensis.
' Retrieved 3 July 2014.Loiselle, P.V.; and Rodriguez, D. (2007). ''A new species of Bedotia (Teleostei: Atherinomorpha: Bedotiidae) from the Rianila drainage of Eastern Madagascar, with redescriptions of Bedotia madagascariensis and Bedotia geayi.'' Zootaxa 1520: 1-18. In addition to

meristics Meristics is an area of ichthyology and herpetology which relates to counting quantitative features of fish and reptiles, such as the number of fins or scales. A meristic (countable trait) can be used to describe a particular species of fish, or us ...

, the two can be separated by the exact colour pattern on their tail fin (males of both typically have red in the tail) and the distinct red spot on the lower jaw of breeding male ''B. geayi'' (lacking in ''B. madagascariensis''). ''B. geayi'' was described in 1907 by Jacques Pellegrin from a type collected by the

pharmacist A pharmacist, also known as a chemist (Commonwealth English) or a druggist (North American and, archaically, Commonwealth English), is a healthcare professional who prepares, controls and distributes medicines and provides advice and instructi ...

and natural history collector Martin François Geay (1859-1910), who Pellegrin honoured with its specific name.

References

Zona The red-tailed silverside, or zona (''Bedotia geayi'') is a species of Madagascar rainbowfish endemic to the Mananjary River drainage in Madagascar. It is threatened by habitat loss and introduced species. It has often been confused with the rel ...

Freshwater fish of Madagascar Taxonomy articles created by Polbot Fish described in 1907 {{Atheriniformes-stub