Oman Mountains




Brian Coad, Jennifer Hales


Saudi Arabia
United Arab Emirates

Major Habitat Type

Xeric freshwaters and endorheic (closed) basins

Drainages flowing into

Sea of Oman and Persian (= Arabian) Gulf, and internal basins of the southeast Arabian Peninsula

Main rivers to other water bodies

There are no major rivers or lakes in the ecoregion. Small wadis and springs are the main water bodies, with aflaj (= qanats) also being a water source containing fishes. At the southwestern side of the ecoregion is the Umm as Samin, a low-lying salt flat at the edge of the Rub’ al Khali.



This ecoregion is located in the southeastern part of the Arabian Peninsula. Lying mostly within Oman and the United Arab Emirates, it is bounded by the Persian (= Arabian Gulf), Strait of Hormuz, Gulf of Oman, Arabian Sea, and Rub’ al Khali Desert (part of the Arabian Interior ecoregion [440]).


The largest landform in the ecoregion is the Al Hajar Mountains, separated into the Al Hajar al Gharbi (Western Al Hajar) Mountains and the Al Hajar ash Sharqi (Eastern Al Hajar) Mountains. The highest part of this range is Al Jabal al Akhdar (Green Mountain), which rises over 2900 m, and is part of the Al Hajar al Gharbi Mountains. This range is surrounded by interior sand deserts and a narrow coastal strip. The ecoregion is isolated from other freshwater ecoregions by the Rub’ al Khali Desert and the surrounding ocean.

Freshwater habitats

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.

Terrestrial habitats

There are three terrestrial ecoregions with the Oman Mountains ecoregion. The Gulf of Oman desert and semi-desert terrestrial ecoregion includes the low-lying Batinah plain that stretches 270 km between the foothills of Al Hajar Mountains and the sea. This ecoregion surrounds the base of the Al Hajar Mountains, and includes a complex system of wadis that drain the mountain slopes. Common indigenous tree species include Zizyphus spina-christi, Ghaf (Prosopis cineraria), and umbrella thorn acacia (Acacia tortilis). The Al Hajar montane woodlands characterize the mountain region, with species such as Moringa peregrina, Ficus cordata salicifolia, F. johannis, umbrella thorn acacia, and Prunus Arabica. The interior part of the ecoregion is characterized by the Arabian Desert and East Sahero-Arabian xeric shrublands. Typical species in this ecoregion include Calligonum crinitum, saltbush (Cornulaca arabica), and the sedge Cyperus conglomeratus.

Description of endemic fishes

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).

Justification for delineation

This ecoregion contains an impoverished fauna with relatives to the east and wholly endemic primary freshwater fish.

Level of taxonomic exploration



  • Alkahem, A. F.;Behnke, R. J. (1983). "Fishes of Saudi Arabia/Freshwater Fishes of Saudi Arabia" Fauna of Saudi Arabia
  • Krupp, F. (1983). "Fishes of Saudi Arabia. Freshwater fishes of Saudi Arabia and adjacent regions of the Arabian Peninsula" Fauna of Saudi Arabia 5 pp. 568-636.
  • World Wildlife, F. (2001). "Terrestrial Ecoregions of the World" 2005 (2005;
  • Hijmans, R. J., S. Cameron and Parra., J. (2004) \WorldClim, Version 1.4 (release 3). A square kilometer resolution database of global terrestrial surface climate\ "<"[]">" (16 July 2009)
  • IUCN (2009) \IUCN Red List of Threatened Species. Version 2009.1\ "<"">" (08 July 2009)