Wadis form a unique environmental system characterised by variety, diversity, and a wealth of natural attractions. Within this fertile environment, people have lived in the wadis of Oman for thousands of years. There are no major rivers or lakes in the ecoregion. Small wadis and springs are the main water bodies, with aflaj also being a water source containing fishes. Most water bodies are very small, subject to drying, intermittent connections, and flash floods. Aflaj are an important habitat (although artificial structures) since they support a fish fauna in areas where the water table may fall and dry up natural flows and, as a traditional water supply, are variously maintained or abandoned for pump wells.
Only five fish species are recorded, two of which are of marine origin but live in fresh waters permanently. Species include the Killifish (Aphanius dispar), freshwater Goby (Awaous aeneofuscus), and the cyprinids Cyprinion microphthalmum, Garra barreimiae, and G. longipinnis. There are no endemic genera, but the three cyprinid species are endemics with endemic subspecies. Garra barriemiae and G. longipinnis are listed as Vulnerable in the Red List (IUCN 2009). The cyprinid species show affinities to the east across the Straits of Hormuz rather than to the rest of the Arabian Peninsula. There is a subterranean, blind population of Garra barreimiae that inhabits a deep cave of the south flank of the Jabal Ahkdar. It shows poorly developed optic lobes, but re-growth occurred in light.

Freshwater Ecoregion of the World : #443 Oman Mountains

Major Habitat Type: xeric freshwaters and endorheic (closed) basins