Key to species of Carasobarbus in Persian Gulf basin

1a - Lower lip without median lobe; one pair of barbels (two pair in the Makran population). ……………… C. luteus

1b - Lower lip with median lobe; two pair barbels. ………………2

2a - 24 − 29 total lateral-line scales; lower lip lobe well-developed (Coad and Najafpour, (1) data included). ……………… C. sublimus

2b – 32–44 total lateral-line scales; lower lip lobe slightly to relatively developed..………………3

3a - 32–37 total lateral-line scales. ………………4

3b - 38–44 total lateral-line scales. ………………5

4a – Lower lip lobe well-developed; 32–77 [mode 36] total lateral-line scales; head length 25–27% SL; posterior barbel 13–20% HL; snout length 36–44% HL. ……………… C. kosswigi

4b - Lower lip lobe slightly developed; 32–34 [mode 33–34] total lateral-line scales; head length 20–24% SL; posterior barbel 21–38% HL; snout length 25–31% HL. ……………… C. hajhosseini sp. n.

5a – A prominent black blotch on end of caudal peduncle in specimens <85 mm SL; head length 22–25% SL; dorsal fin height 19–26% SL; distance between base of pelvic and anal fins 24–25% SL. ……………… C. doadrioi sp. n.

5b – No black blotch on end of caudal peduncle in specimens <85 mm SL; Head length 19–20% SL; dorsal fin height 26–30% SL; distance between base of pelvic and anal fins 26–28% SL. ……………… C. saadatii sp. n.