Oxynoemacheilus ercisianus Common name. Van loach. Diagnosis. Distinguished from other species of Oxynoemacheilus in adjacent Euphrates drainage by: ○ scales absent / ○ lateral line incomplete not reaching or reaching below dorsal base / ○ suborbital groove absent in male / ○ caudal slightly emarginate / ○ supratemporal canal without central pore / ○ pelvic axillary lobe absent / ○ dorsal adipose crest on caudal peduncle high, not reaching to vertical through last anal ray base in individuals larger than 50 mm SL / ○ caudal–peduncle length 1.0–1.3 times its depth / ○ body width at dorsal origin 13–17 % SL / ○ flank with a marmorated pattern or with large, irregularly shaped and narrowly spaced dark-brown bars or blotches, usually more prominent on flank behind dorsal base / ○ caudal base with mottled colour pattern, without bold, black bar or bold, black spots upper and lower caudal base. Size up to 82 mm SL. Distribution. Türkiye: Lake Van and its tributaries Zilan, Deli, Bendimahi and Karasu. Habitat. Moderately flowing streams and rivers with gravel or rock substrate. Also, in microbialites of Lake Van itself, at a maximum depth of 13 m and about 500 m offshore. Biology. No data. Conservation status. VU; appears to be declining within its small range. Remarks. Nemacheilus pulsiz is a synonym. Further reading. Erk’akan & Kuru 1986 (description); Krupp 1992a (description of Nemacheilus pulsiz); Freyhof et al. 2019b (diagnosis, distribution); Akkuş et al. 2021 (habitat in Lake Van).

Published as part of Freyhof, Jörg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, GmbH, Berlin / Boston :De Gruyter on pages 500-501, DOI: 10.1515/9783111677811, http://zenodo.org/record/17881367