Onilahy River


Onilahy is a river in Toliara Province, 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.
Two species of cichlids are endemic to the river basin, but Ptychochromis onilahy is probably already extinct and the remaining range of Ptychochromoides betsileanus covers less than.