Ecoregion Description

701: Baluchistan

Major Habitat Type:

xeric freshwaters and endorheic (closed) basins

Author:

Brian Coad

Countries:

Afghanistan; Iran; Pakistan

Boundaries:

Baluchistan (or Balochistan) comprises Iranian and Pakistani Baluchistan, delimited by the Arabian Sea to the south, the Sulaiman Mountains to the east, the Chagai and Toba Kakar ranges in the north, and the Hazaran massif in the west. It is bordered by the Northern Hormuz Drainages ecoregion [451] to the west, Lower and Middle Indus [703] to the east, and Hilmand-Sistan [702] and Kavir & Lut Deserts [448] to the north.

Drainages flowing into:

The ecoregion drains to the Arabian Sea and Gulf of Oman (Sea of Oman), as well as several endorheic basins in the northern part of the ecoregion.

Main rivers or other water bodies:

The main water bodies include the Sarbaz, Dasht, and Hingol rivers, and the Tahrud, Jaz Murian, Mashkel, Baddo, and Pishin-Lora endorheic basins.

Topography:

The plateau of Baluchistan lies at the southeastern end of the Iranian Plateau. It is divided from the narrow Makran coastal plain by the Central Makran Range and the Makran Coastal Range. The ecoregion also includes low-lying internal basins. Elevations range from sea level to over 4300 m.

Climate:

This ecoregion falls within a hot desert climate, with summer temperatures that exceed 44 °C. Winters are very cold in the highlands, but mild along the Makran coastal plain where temperatures remain above 0 °C. The mean annual temperature of the ecoregion is 22 °C, and mean annual precipitation is 117 mm.

Freshwater habitats:

All streams in the ecoregion are small, many are intermittent, and some dry out completely. Small dams, springs, and qanats are also important habitats.

In the west is the Hamun-e Jaz Murian, which is a marshy lake that is dry for most of the year, but fills with fresh water in winter. It is fed by the Halil and Bampur rivers.

The rivers and streams of the Makran coastal plain drain to the sea at the Straits of Hormuz and the Gulf of Oman. Most streams of the Makran, however, have little running water and regularly dry up along much of their length.

Terrestrial Habitats:

A large part of the ecoregion is rocky desert and semi-desert. There are sand dunes in some parts, but mostly rocky desert and hills with sparse scrub vegetation. There are also isolated areas of surviving natural forest, tree crops, and irrigated farming.

Fish Fauna:

There are around 130 species, some of which are marine entrants into coastal rivers (clupeids, mugilids, and gobiids).

The ecoregion is transitional in nature, represented by the distributional limits of certain wide-ranging species. This is most notable for species reaching their westernmost limits, namely Gangetic latia (Crossocheilus latius), dwarf snakehead (Channa gachua), pool barb (Puntius sophore), and mahasher (Tor putitora). In contrast to those species reaching their western limits, the cyprinid Capoeta damascina has a distribution that is principally Southwest Asian and reaches its eastern limit in Baluchistan.

Description of endemic fishes:

Three species are endemic to the ecoregion: Indian River shad (Gudusia chapra), Indian potasi (Neotropius atherinoides), and a river loach (Schistura alepidota). Two near-endemic Labeo species (L. gedrosicus, L. macmahoni) have not been recently re-examined in detail.

Other noteworthy aquatic biotic elements:

The gandoo or marsh crocodile (Crocodylus palustris) occurs in the Dasht and Sarbaz rivers on the Pakistan-Iran border.

Evolutionary phenomena:

This ecoregion is a  transitional zone between the Palaearctic and Oriental realms, with species such as Capoeta and Cyprinion from the former and Labeo, Puntius, and Channa from the latter.

Justification for delineation:

This ecoregion has a transitional nature, which is represented by the distributional limits of certain wide-ranging species.

The ecoregion is also noted for the Bahu Kalat protected area on the coast of Iran and the Zangi Nawar Lake in the north of Pakistan, which has been proposed as a Ramsar site.

Level of taxonomic exploration:

Good

References/sources:

Coad, B. W. (1996). "Freshwater fishes of Iranian and Pakistani Baluchistan" Biologia 42(1&2) 1-18.

Coad, B. W. (2002). "Freshwater Fishes of Iran" (www.briancoad.com).

Scott, D. A. (Ed.) (1995). "A Directory of Wetlands in the Middle East" Gland, Switzerland and Slimbridge, U.K: IUCN and International Waterfowl and Wetlands Research Bureau.