Paraschistura alta, Nalbant & Bianco, 1998

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 556-557

Paraschistura alta

Common name. Helmand banded loach.

Diagnosis. Distinguished from other species of Paraschistura in West Asia by: ● processus dentiformis in upper jaw absent / ○ lateral line complete or almost complete (incomplete in Iranian fish), reaching to caudal base / ○ flank and caudal peduncle covered by scales / ○ snout long and pointed / ○ caudal forked / ○ 7½ or 8½ branched dorsal rays / ○ pelvic origin below second or third branched dorsal ray / ○ no dorsal adipose crest / ○ suborbital flap or groove absent in male / ○ a small, bold black spot at base of first dorsal rays / ○ black bar at caudal base faint / ○ 9–10 regularly set and shaped pale-brown or grey bars, absent or very faint on flank in front of dorsal origin / ○ caudal–peduncle depth 0.9–1.2 times

longer than deep / ○ body depth at dorsal origin 12–20 % SL. Size up to 112 mm SL.

Distribution. Afghanistan and Iran: Sistan basin, including Helmand drainage, Chahnime reservoirs, Hamun Lakes, and Zehak.

Habitat. Large and medium-sized rivers.

Biology. No data.

Conservation status. LC; situation in Helmand unknown.

Remarks. This species was originally described as having a complete or almost complete lateral line, which is incomplete in fish recorded from Iran. Whether this species has a suborbital groove or flap in males remains unknown; it is absent in the few individuals examined.

Further reading. Nalbant & Bianco 1998 (description); Jouladeh-Roudbar et al. 2015c (record from Iran).

The Hamoun: From wetlands to wastelands.

The Helmand rises in the Hindu Kush mountain

range, situated west of Kabul in Afghanistan. It

crosses the Dashti Margo desert before reach-

ing the Hamoun or Sistan Lake region, located

at the border between Afghanistan and Iran.

The Hamoun wetlands, which form a true oasis

in the middle of hundreds of kilometers of arid

plains, are a testament to the river’s influence.

The marshes and lakes of the Hamoun wetlands Copernicus Service information 2024

supported a diverse range of wildlife and were

an important stopover for migrating birds. Furthermore, the wetlands were the source of livelihood for thousands of people who depended on agriculture and fishing in the area. However, many factors, including improved irrigation practice, urban development, dams, and drought, led to a gradual decline in the wetlands since the 1970s. Since the 1990s, the Hamoun wetlands have deteriorated rapidly due to the expansion of irrigation, coupled with one of the worst droughts ever recorded. One of the major dams blocking water to the Hamoun wetlands is the Kajaki dam, located in central Afghanistan. The Taliban government closed the sluices of the dam in 1998 after a dispute with Iran. At the same time, severe droughts massively decreased the precipitation in the Hindu Kush. Until 2001, the Hamoun wetlands had completely dried out. The post-Taliban government in Kabul agreed to open the sluices again in late October, allowing water to reach the Hamoun wetlands again. The new Taliban government allows surplus water to flow during high floods. Much work still needs to be done to restore the wetlands, including ensuring adequate water flow to sustain the ecosystem. When the dam is opened, fish from Afghanistan, including the loach Paraschistura alta , are washed downriver. Further reading. Rashki et al. 2013 (Sistan Oasis)

Paraschistura aredvii ; Sarab-e Bahram spring, Iran; 39 mm SL.