The Bedotiidae are a family of fish known as the Madagascar rainbowfish, Madagascan rainbowfish, or Malagasy rainbowfish due to their endemism to Madagascar. It includes two genera, Bedotia and Rheocles.
Anatomy and morphology
As the common name rainbowfish implies, they are generally colorful fishes. Bedotiids are elongated, laterally compressed, and rarely exceed 100 mm in standard length. Bedotiids exhibit varying degrees of sexual dimorphism, which is quite pronounced in some species.
The entire family of Bedotiidae is endemic to Madagascar. Bedotiids occur exclusively in freshwater environments and are distributed in small to medium-sized forested rivers and streams, occasionally in swamps and marshes, spanning nearly the entire eastern slope of Madagascar (R. derhami is recorded from a westward draining Sofia River basin in the northeast of the island).
Bedotiid fishes are under severe threat because of rapid deforestation and habitat modification throughout most of their range. Because Bedotia and Rheocles are generally the first to exhibit population declines or disappear from areas where habitat is moderately to highly disturbed or degraded, they are reliable indicators of ecosystem health and stability.
This family includes the two genera Bedotia and Rheocles, with at least 13 species. This family is monophyletic. This group is considered by Nelson, 2006 Fishes of the World to be a subfamily of the family Melanotaeniidae. In a 2004, this family is placed in a suborder Melanotaenioidei which includes the sister groups Bedotiidae and Melanotaeniidae, as well as Pseudomugilidae (including Telmatherinidae). The sister-group relationship between Bedotiidae and Melanotaeniidae is most parsimoniously explained by the break-up of Gondwana.
- Sparks, John S.; Smith, W. Leo (2004). "Phylogeny and biogeography of the Malagasy and Australasian rainbowfishes (Teleostei: Melanotaenioidei): Gondwanan vicariance and evolution in freshwater" (PDF). Molecular Phylogenetics and Evolution. 33 (3): 719–734. doi:10.1016/j.ympev.2004.07.002. PMID 15522799.
- Nelson, Joseph S. (2006). Fishes of the World. John Wiley & Sons, Inc. ISBN 0-471-25031-7. OCLC 224053746.
- Sparks, John S.; Rush, Leila M. R. (2005). "A new rainbowfish (Teleostei: Melanotaenioidei: Bedotiidae) from the southeastern highlands of Madagascar, with comments on the biogeography of Bedotia" (PDF). Zootaxa. 1051: 39–54.
- Sparks, John S.; Schaefer, S. A. (2001). Schaefer, S. A., ed. "Bedotia masoala: A New Species of Atherinoid Rainbowfish (Teleostei: Bedotiidae) from the Masoala Peninsula, Northeastern Madagascar". Copeia. 2001 (2): 482–489. doi:10.1643/0045-8511(2001)001[0482:BMANSO]2.0.CO;2.
- Stiassny, Melanie L. J. (August 7, 1990). "Notes on the Anatomy and Relationships of the Bedotiid Fishes of Madagascar, with a Taxonomic Revision of the Genus Rheocles (Atherinomorpha: Bedotiidae)" (PDF) (2979): 1–33.