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.
Paretroplus nourissati, the lamena, is a species of cichlid from the vicinity of the confluence of the Amboaboa and Mangarahara Rivers near Mandritsara in northern Madagascar. This relatively elongate Paretroplus reaches about 16 centimetres (6.3 in) in length, and is closely related to P. lamenabe and P.tsimoly. P. nourissati is threatened by habitat loss and invasive species.
Paretroplus polyactis is a vulnerable species of cichlid found widely in fresh and brackish water in coastal regions and associated river basins in eastern Madagascar. It is the only Paretroplus found in the southern half of Madagascar, and one of only two found in eastern drainages. P. polyactis is threatened by habitat loss and overfishing. This relatively deep-bodied Paretroplus reaches 30 centimetres (12 in) in length. It shares a large part of its range with a cichlid from another genus, Ptychochromis grandidieri.
Paretroplus gymnopreopercularis is a species of cichlid from the vicinity of the confluence of the Amboaboa and Mangarahara Rivers near Mandritsara in northern Madagascar. Until its official scientific description in 2008, it was temporarily known as the Paretroplus nov. sp. "sofia". It is endangered because of habitat degradation, overfishing and invasive species. Following the construction of a dam on the Mangarahara River, surveys have failed to relocate P. gymnopreopercularis in this river.
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.
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 20cm, but P. insolitus reaches 25, while P. grandidieri and P. oligacanthus reach 35 and 20cm respectively. The largest species was P onilahy which may have reached as much as 45cm if reports of fishermen are to be believed.
Ptychochromis inornatus is an endangered species of cichlid endemic to the Ankofia River basin and its tributaries in the eastern part of the Mahajanga Province in Madagascar. It is threatened by habitat loss. It reaches 12.2 cm (4.8 in) in standard length.
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.
Ptychochromis curvidens is an endangered species of fish in the cichlid family. It is endemic to a few rivers that flow west from Montagne d'Ambre in far northern Madagascar. It is threatened by habitat loss and introduced species. It reaches about 14.7 cm (5.8 in) in standard length.
Ptychochromis onilahy is a species of cichlid endemic to the Onilahy River in southwestern Madagascar. Despite several recent visits to the region, this species has not been recorded since 1962 when the only known five specimens were collected. It is listed as extinct by the IUCN, but the Onilahy River system is large, and there is a small chance remnant populations exist in remote regions. This species can reach a length of 8.6 centimetres (3.4 in) SL.
The trondo mainty is a critically endangered species of cichlid endemic to the Onilahy River Basin in southwestern Madagascar. Its remaining range covers less than 10 km2 (3.9 sq mi) and it is highly threatened by habitat loss, fishing, and competition with/predation by introduced species. Another cichlid from the same basin, Ptychochromis onilahy, is probably already extinct. The trondo mainty reaches a standard length (SL) of 24 cm (9.4 in).
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.
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.
The two-finned round herring is a species of fish in the family Clupeidae. It is endemic to Madagascar. Its natural habitat is rivers. It is the only species in its genus.
Ptychochromis insolitus, also known as the Mangarahara cichlid or joba mena, is a species of cichlid endemic to certain river systems in northern Madagascar. This critically endangered fish is threatened by habitat loss and competition from introduced species; after the last-known female was killed during a breeding attempt, its conservation received significant international attention as London Zoo launched a media campaign to identify any remaining individuals. A remnant population was discovered by aquaculture entrepreneur Guy Tam Hyock in 2013, and breeding programs in Madagascar and at Toronto Zoo have resulted in thousands of successful hatchlings.
Ptychochromis makira is a species of cichlid only known from the Antainambalana River in the northernmost part of the Toamasina Province in Madagascar. It is threatened by habitat loss and overfishing, and has suffered a severe decline in recent years. It reaches a length of 14.6 centimetres (5.7 in) SL.
Ptychochromis ernestmagnusi is a species of fish cichlid only known from the Mananara du Nord River in northeastern Madagascar, but it is probably more widespread in that region. If so, it likely occurs in the Mananara-Nord Biosphere Reserve, which would give it a level of protection. It can reach 14.7 cm (5.8 in) in standard length. The specific name honours Ernest Magnus (1908-1983) who was the uncle of the German-American marine biologist and ichthyologist Rudolf Arndt who gave generous support to the author's research, at the request of Anrdt's family, whose “generous gift” supported the authors’ research. Magnus played an important part in assisting the Arndt family to survive in Berlin after the Second World War and then emigrate to New York City in 1950, by giving them "food, clothing, shelter, love, many kindnesses and moral support".
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.
Ptychochromis mainty is a species of cichlid from the subfamily Ptychochrominae, a subfamily which is endemic to the freshwaters of Madagascar. It has only been recorded from forested streams in the vicinity of Fort Dauphin in the south eastern part of the island. Its closest relative is Ptychochromis grandidieri.
