Boundaries

The ecoregion encompasses the basins of the upper Amu Darya tributaries: Pyandzh (Piandj), Surkhandarya, Kafirnigan, Vakhsh, and Kunduz. It also includes the upper Zeravshan (upstream from Pendzhikent), upper Tedzhen (Herirud=Hari Rud=Tejent Deryasy), Murghab rivers (upstream from the Karakumskiy Canal system), and river drainages in northern Afghanistan west from Kunduz (the former tributaries of the Amu Darya that do not presently reach it).

The ecoregion’s northern border (with the Middle Amu Darya ecoregion [630]) runs along the northern spurs of the Badkhyz Hills and the Karabil’ Hills. It next approaches the main course of Amu Darya, where it travels up to the lower reaches of the Panj and Vakhsh rivers. Then, the border runs northwest along the lower reaches of the Vakhsh, Kafirnigan [Kofarnihon], and Surkhandarya [Surkhondaryo] rivers, and then north along the Chakchar Range. The border (with the Central Asian Highlands ecoregion [628]) runs further east along the Turkestanskiy and Alayskiy ranges that divide the Zeravshan and Kyzylsu [Qizilsu] (Vakhsh) headwaters from the Syr Darya [Sirdario] tributaries flowing to the Fergana Valley (in ecoregion 628).

Topography

The ecoregion encompasses mostly mountainous areas ranging from 240 m to over 7100 m asl in the Pamir Mountains.

Freshwater habitats

The majority of tributaries of the Pyandzh River are mountain streams with extremely high flow velocities. The bottoms are usually comprised of boulders or pebbles, although a thin layer of silt occurs in in a few backwaters. In the Pamir and Nurestan areas, melting glaciers feed the rivers in July and August. As freezing temperatures advance, the flow rate greatly diminishes; however, rivers are usually not covered by ice.

Terrestrial habitats

The terrestrial habitats of the ecoregion range from desert and semi-desert in the north and west, alpine desert and tundra in the east, open woodlands in the northeast, and mainly xeric woodlands and alpine meadow in the central and southern part of the ecoregion.

Description of endemic fishes

Leuciscus latus, the only strict endemic species in the ecoregion, is a rheophylic dace that is most closely related to Zeravshan dace (L. lehmanni) in the Zarafshan River. It represents the outernmost member of the Leuciscus genus. It has a limited native distribution, avoiding both stagnant waters and shallow fast-running streams.

Other noteworthy fishes

Garra rossica (also known as Discognathus rossicus) is found in Tedzhen and the Upper Murghab. It is now known as an aquarium fish, but its native range needs clarification. It is a typical mountainous species with a modified mouth for feeding on periphyton.

 Gobio lepidolaemus nikolskyi is a poorly known gudgeon commonly considered conspecific with G. gobio lepidolaemus. At present, the complex \"Gobio gobio\" is under revision (papers published and in preparation by Kottelat, Freyhof, Persat, Naseka), and at least 20 species will be described or re-established within the complex.

Schistura sargadensis turcmenicus is known only from its original description from the Murghab River and rivers of the northern slope of Eastern and Central Kopet-dag. It is questionable if it is conspecific with the near-endemic Turkmenian loach (Schistura sargadensis) from Eastern Iran.

Triplophysa stoliczkai uranoscopus is a stone loach known by only its original description from the Upper Amu Darya (Khodzauk). The whole complex \"T. stoliczkai\" needs taxonomic revision.

Amu-Darya trout (Salmo trutta oxianus) is an endemic subspecies that occurs in the upper reaches of the Amu Darya and in its tributaries, the Kafirnigan and Surkhandarya rivers. In some areas it is quite abundant. Its body length reaches 60 cm and its weight reaches up to 7.5 kg. In lakes and reservoirs it forms semi-anadromous and resident forms, and in rivers there are completely riverine forms. Its spawning migration begins in September; it spawns in rivers in September – October, and in reservoirs in November – December at water temperatures of 9-10 °C.

Kessler’s loach (Schistura kessleri) is a poorly studied species from Iran. It is probably represented in the ecoregion by a distinct subspecies (or species), Schistura kessleri turcomanus. This subspecies is known from only four specimens from the Kushka River.

Balitorids of the ecoregion need further taxonomic studies.

Justification for delineation

The ecoregion is the high-latitude part of the Amu Darya drainage basin, and displays clear affinities with the Middle Amu Darya [630]. On the generic level, the fauna of this ecoregion is close to the Upper Syr Darya River fauna (in ecoregion 628), but different on the species level. Besides, this ecoregion lacks Petroleuciscus and Cottus.

Level of taxonomic exploration

Poor