Gobio nigrescens (Keyserling, 1861)

Gobio nigrescens View in CoL View Figure

Common name. Hari gudgeon.

Diagnosis. Distinguished from G. caucasicus , the geographically most adjacent species in Caspian basin by: ○ pectoral reaching 3–5 scales in front of pelvic origin in mature male / ○ no scales on chest and between pectorals. Size up to 95 mm SL.

Distribution View Figure . Hari drainage in Afghanistan, Iran, and Turkmenistan. Amu Darya and Zeravshan in Central Asia (recorded from Uzbekistan). Also, in Kashaf ( Iran).

Habitat. Slow to moderate-flowing streams and rivers with sandy or gravelly bottoms.

Biology. No data.

Conservation status. LC; extirpated from Kashaf drainage.

Remarks. This species is not related to other West Asian gudgeons but belongs to a group of Central Asian and Siberian species. It is sometimes identified as G. lepidolaemus from the adjacent Aral basin, from which it differs in chest without scale (vs. covered with scales), more scale rows on the caudal peduncle (½3/1/3½ vs. ½2/1/2½) and 16 circumpeduncular scales (vs. 12–14). Gobio populations found in Morghab and rivers of Kopek Dag in Turkmenistan are awaiting identification and may belong to this species.

Further reading. Mousavi-Sabet et al. 2016a (description); Sheraliev & Peng 2021 (distribution in Uzbekistan).