Rheocles

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Rheocles
Rheocles-alaotrensis.png
Rheocles alaotrensis
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Atheriniformes
Family: Melanotaeniidae
Subfamily: Bedotiinae
Genus: Rheocles
D. S. Jordan & C. L. Hubbs, 1919
Type species
Eleotris sikorae
Sauvage, 1891
Synonyms
  • RheocloidesNichols and La Monte, 1931

Rheocles is a genus of Madagascar rainbowfish. Rheocles has a restricted distribution, being found only in certain forested freshwater habitats in the central and eastern highlands of Madagascar including the Nosivolo River. [1] The genus appears to feed almost exclusively on allochthonous material, primarily insects falling onto the water surface. [2]

Contents

Taxonomy

In a 1990 study, this genus is monophyletic. [2] However, in a 2004 analysis, it was found that Rheocles was paraphyletic, forming two distinct clades. R. alaotrensis, R. lateralis, and R. wrightae (all species that are not discernibly sexually dimorphic was recovered as the sister taxon of the rest of the bedotiids, including Bedotia sister to R. vatosa + R. derhami. R. pellegrini and R. sikorae were excluded from this study due to lack of available material, however, R. sikorae is considered to be the sister taxon to R. wrightae. [3]

Species

There are currently seven recognized species in this genus: [4]

Description

Rheocles species are robust bedotiids with little lateral body compression. [2] R. vatosa and R. derhami are sexually dimorphic, with males exhibiting larger adult size, enhanced coloration and pigmentation, as well as pronounced development of the unpaired fins. [3]

Conservation

Its close association with forested biotopes suggests that, like so many other rainforest-adapted series, Rheocles is extremely vulnerable to deforestation pressure. [1]

Related Research Articles

<span class="mw-page-title-main">Atheriniformes</span> Order of fishes

The Atheriniformes, also known as the silversides, are an order of ray-finned fishes that includes the Old World silversides and several less-familiar families, including the unusual Phallostethidae. The order includes at least 354 species. They are found worldwide in tropical and temperate marine and freshwater environments.

<span class="mw-page-title-main">Onilahy River</span> River in Anosy, Madagascar

Onilahy is a river in Atsimo-Andrefana and Anosy, southern Madagascar. It flows down from the hills near Betroka to the Mozambique Channel. It empties at St. Augustin, and into the Bay of Saint-Augustin.

<i>Bedotia</i> Genus of fishes

Bedotia is a genus of the family Bedotiidae of fishes endemic to Madagascar.

<span class="mw-page-title-main">Bedotiinae</span> Family of fishes

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 Rheocles.

<i>Paretroplus</i> Genus of fishes

Paretroplus is a genus of fishes in the cichlid family, all of which are endemic to lakes and rivers of Madagascar. The vast majority are threatened and restricted to the northwestern part of the island. Only P. polyactis is found in the southern half of Madagascar and only P. polyactis and P. gymnopreopercularis are found in eastern drainages. Most are restricted to freshwater, but at least P. polyactis and P. maromandia can also be seen in brackish habitats.

<i>Ptychochromis grandidieri</i> Species of fish

Ptychochromis grandidieri is a species of fish in the family Cichlidae endemic to river basins along a large part of the eastern coast of Madagascar, although it has been recorded as far as 100 km (62 mi) inland. Uniquely in the genus Ptychochromis, this species also occurs in brackish water. It reaches 35cm in standard length. It shares a large part of its range with a cichlid from another genus, Paretroplus polyactis. The specific name honours Alfred Grandidier (1836-1921), the French naturalist and explorer who, with Henri Joseph Léon Humblot (1852-1914), collected the type.

<i>Ptychochromis</i> Genus of fishes

Ptychochromis is a genus of cichlids endemic to rivers and lakes in Madagascar. One species can also be seen in brackish water. Most species in this genus are threatened, and P. onilahy is probably extinct. Most reach a length of 15 to 20 cm, but P. insolitus reaches 25 cm (10 in), while P. grandidieri and P. oligacanthus reach 35 cm (14 in) and 20 cm (8 in) respectively. The largest species was P. onilahy which may have reached as much as 45 cm (18 in) if reports of fishermen are to be believed.

Ptychochromis loisellei is a species of cichlid from the Mahanara River basin north of Sambava in northeastern Madagascar. It remains common within its small range, but it is threatened by habitat loss and introduced species. It reaches about 11.9 centimetres (4.7 in). The similar named Paretroplus loisellei is also restricted to the Mahanara River basin. The specific name honours Paul V. Loiselle, Emeritus Curator of Freshwater Fishes at the New York Aquarium and a researcher in, and campaigner for the conservation of, the freshwater fish of Madagascar.

<i>Ptychochromoides</i> Genus of fish in Madagascar

Ptychochromoides is a genus of cichlids endemic to Madagascar. Of the three described species, two are critically endangered and one was considered extinct until rediscovered in late 2010.

Katria is a genus of freshwater fish in the cichlid family. It contains the single species Katria katria, a vulnerable species from the Mangoro and Nosivolo Rivers in east-central Madagascar, that was formerly included in the genus Ptychochromoides. The only other monotypic cichlid genus in Madagascar is Oxylapia, and it is restricted to the same region as Katria. In 2010, the Nosivolo River was designated as a Ramsar Site. The Katria reaches about 13 centimetres (5.1 in) in length.

Rheocles derhami is a species of rainbowfish in the subfamily Bedotiinae, the Madagascar rainbowfishes. It is endemic to the Ambalona River and Mangarahar River in Madagascar. Its natural habitat is rivers. It was described by Melanie Stiassny and Damaris Rodriguez in 1992 and was named in honour of the Swiss conservationist Patrick De Rham.

Rheocles vatosoa is a species of rainbowfish in the subfamily Bedotiinae, the Madagascar rainbowfishes. It is endemic to Madagascar. Its natural habitat is the Lokoho River basin. It is threatened by habitat loss.

Rheocles wrightae, is a species of rainbowfish in the subfamily Bedotiinae, the Madagascar rainbowfishes. It is endemic to Madagascar where its occurs in the Manambola River, near Anosibe. It is threatened by habitat loss. It was described by Melanie Stiassny in 1990 from a type locality given as "Sandrangato River, south of Moramanga".

Sauvagella robusta is a small species of fish in the family Clupeidae. It is endemic to the Amboaboa and Mangarahara River Basins in northern Madagascar. This relatively slender fish reaches a length of 6.8 cm (2.7 in), and is overall pale yellowish with silvery on the lower parts. Its current conservation status is unclear, but the cichlid Ptychochromis insolitus, which is highly threatened from habitat loss, is native to the same region. Sauvagella robusta is known to survive at least in Lake Tseny.

Paretroplus loisellei is a vulnerable species of cichlid fish from the Mahanara River basin north of Sambava in northeastern Madagascar. Until its scientific description in 2011, this population was usually referred to as Paretroplus sp. nov. "Ventitry" or included in P. damii, which it resembles. It reaches about 15 centimetres (5.9 in) in length, and is threatened by habitat loss and introduced species. The similar named Ptychochromis loisellei is also restricted to the Mahanara River basin. The specific name honours Paul V. Loiselle, Emeritus Curator of Freshwater Fishes at the New York Aquarium and a researcher in, and campaigner for the conservation of, the freshwater fish of Madagascar.

Melanie Lisa Jane Stiassny is the Axelrod Research Curator of Ichthyology at the American Museum of Natural History. Her research interests focus on freshwater biodiversity documentation and systematic ichthyology in the Old World tropics, including tropical Africa and Madagascar. She has published broadly on the biogeography conservation and systematics of teleosts.

<i>Spinomantis tavaratra</i> Species of amphibian

Spinomantis tavaratra is a species of frogs in the mantellid subfamily Mantellinae. It is endemic to the humid forests of northwestern Madagascar.

Limia melanonotata, the blackbanded limia, is a toothcarp in the family Poeciliidae. It is endemic to the island of Hispaniola.

Louise H. Emmons is an American zoologist who studies tropical rainforest mammals, especially rodents. She has conducted fieldwork in Gabon, Sabah (Borneo), Peru, and Bolivia. Her best known work is the field guide, Neotropical Rainforest Mammals: A Field Guide, first published in 1990, with a second edition in 1997.

Claus Herluf Stenholt Clausen was a Danish ichthyologist, known for his work on the river fish of West Africa. Although often cited as H. S. Clausen, he published as H. Stenholt Clausen, with the compound surname Stenholt Clausen. He worked for many years at the University College of Ibadan in Nigeria.

References

  1. 1 2 Stiassny, Melanie L. J.; Reinthal, Peter N. (February 24, 1992). "Description of a New Species of Rheocles (Atherinomorpha, Bedotiidae) from the Nosivolo Tributary, Mangoro River, Eastern Malagasy Republic". American Museum Novitates. American Museum of Natural History (3301): 1–8. hdl:2246/4996.
  2. 1 2 3 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)". American Museum Novitates. American Museum of Natural History (2979): 1–33. hdl:2246/5063.
  3. 1 2 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.
  4. Froese, Rainer and Pauly, Daniel, eds. (2012). Species of Rheocles in FishBase . June 2012 version.