Squalius cii Common name. Marmara chub. Diagnosis. Distinguished from other species of Squalius in Western and Central Anatolia by: ○ 14–16 circumpeduncular scales / ○ anal rays hyaline or pale-orange in live and preserved individuals / ○ anal membranes distinctly black / ○ upper lip clearly projecting beyond lower lip / ○ upper head profile almost straight / ○ vertical black bar behind opercle in-conspicuous / ○ 45–49 total lateral-line scales / ○ head length 24–26 % SL / ○ scale pockets on flank with a dark-grey, crescent-shaped mark / ○ belly between anus and posterior extremity of pelvic base slightly compressed / ○ head width at nape 36–41 % SL. Size up to 255 mm SL. Distribution. Türkiye: Lake İznik basin, Sursuluk drainage, Biga Peninsula (Marmara basin) south to Karamenderes (Aegean basin). Habitat. A wide range of lakes, streams, and rivers, including adjacent reservoirs, from which it migrates into tributaries to spawn. Biology. No data. Conservation status. LC. Remarks. Squalius cephaloides from streams Teşvikiye and Armutlu is a synonym. Further reading. Özuluğ & Freyhof 2011 (description); Bayçelebi et al. 2022 (synonymy of S. cephaloides).

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 page 408, DOI: 10.1515/9783111677811, http://zenodo.org/record/17881367