Family Gobionidae Gudgeons Gudgeons are a family of Cypriniformes that are most diverse in East Asia, from the Amur drainage southward to Central Vietnam; some 28 genera and 231 species are known. In West Asia, there are 17 species, all of which, except Pseudorasbora, being benthic fishes with a flat belly, laterally spread pectoral fins, a single pair of maxillary barbels, and 6½ branched anal rays (vs. 5½ in most Cyprinidae). Some Asian genera exhibit a markedly different morphology from that of true gudgeons. They have a more compressed body, the mouth is inferior to subterminal (even superior in Pseudorasbora and a few others), and they are distinguished from many other East Asian Cypriniformes by having 6½ branched anal rays. Some species of Sarcocheilichthys are noteworthy for spawning in the gill cavity of unionid freshwater mussels, similar to bitterlings; they, too, have developed an ovipositor. Interestingly, gudgeons and bitterlings are closely related. One East Asian species, Pseudorasbora parva, was accidentally introduced to Europe and Central Asia. From both directions, it made its way to West Asia, where it is now widely established. Except for Pseudorasbora, all gudgeons are superficially similar, bottom-dwelling fishes with a midlateral row of dark-brown or grey blotches on the flank and spotted bodies and fins. Further reading. Bănărescu & Nalbant 1973 (systematics); Turan et al. 2012a (identification of Anatolian species). Key to genera of Gobionidae in West Asia 1a - Barbels absent; mouth superior. ……………… Pseudorasbora 1b - Barbels present; mouth inferior. ………………2 2a - Caudal peduncle 3.1–3.8 times its depth; epithelial crests on scales on back. ……………… Romanogobio 2b - Caudal peduncle 1.5–2.5 times its depth; no epithelial crests on scales on back. ……………… Gobio Key to species of Gobio in West Asia, excluding G. nigrescens from Hari drainage 1a - 42–63 total lateral-line scales. ………………2 1b - 39–45 total lateral-line scales. ………………5 2a - Scales extend forward to level of pectoral origin or to half distance of pectoral origin and isthmus. ……………… G. microlepidotus 2b - Scales on chest almost extend to isthmus. ………………3 3a - Head length 24–27 % SL. ……………… G. hettitorum 3b - Head length 27–29 % SL. ………………4 4a - Distance between anus and anal origin 5–7 % SL;caudal-peduncle length 1.7–2.2 times in caudal-peduncle depth. ……………… G. intermedius 4b - Distance between anus and anal origin 7–8 % SL; caudal-peduncle length 1.4–1.7 times in caudal-peduncle depth. ……………… G. maeandricus 5a - 8–10 scales between posterior extremity of pelvic base and anus. ………………6 5b - 4–8 scales between posterior extremity of pelvic base and anus. ………………7 6a - Diameter of scales on belly approximately equal to pupil diameter. ……………… G. insuyanus 6b - Diameter of scales on belly clearly smaller than pupil diameter. ……………… G. kizilirmakensis 7a - Interorbital distance 1.6–2.2 times in eye diameter. ………………8 7b - Interorbital distance 1.0–1.6 times in eye diameter. ………………10 8a - No black spots on head. ……………… G. gymnostethus 8b - Many small black spots on head. ………………9 9a - Distance between anus and anal origin 5–7 % SL; body depth at dorsal origin 22–27 % SL. ……………… G. fahrettini 9b - Distance between anus and anal origin 7–10 % SL; body depth at dorsal origin 18–22 % SL. ……………… G. baliki 10a - Breast completely scaled, scales extending to isthmus; snout rounded, distinctly concave anterior to nostril. ………………11 10b - Breast naked or incompletely scaled, if scales on chest present, scales extending forward to level of pectoral origin; snout pointed, not or slightly concave anterior to nostril. ………………12 11a - Pectoral reaching to or 1 scale in front of pelvic origin in mature male. ……………… G. caucasicus 11b - Pectoral reaching 3–4 scales in front of pelvic origin in mature male. ……………… G. sakaryaensis 12a - Head length 28–30 % SL. ……………… G. kovatschevi 12b - Head length 24–26 % SL. ……………… G. artvinicus

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 250-251, DOI: 10.1515/9783111677811, http://zenodo.org/record/17881367