Key to the Squalius species in the Persian Gulf basin, the southern Caspian Sea basin and Kavir, Namak and Urmia basins

1a Lateral line with 45–50+1–3 scales; head pointed, slender; head depth 44–53% HL.......................... S. lepidus

1b Lateral line with 39–44+1–3 scales; head blunt, deep; head depth 50–63% HL.................................... 2

2a Knob on lower jaw symphysis wide, thick (Fig. 9); posterior tip of each flank scale with a bold grey or brown, roundish or crescent-shaped blotch (Figs. 3, 5).................................................................. S. namak

2b Knob on lower jaw symphysis narrow, thin or absent (Figs. 10, 11); posterior tip of flank scales without bold blotch (Fig. 5)...................................................................................................... 3

3a Mouth subterminal, upper lip projecting beyond lower lip (Fig. 7); caudal-, anal- and pelvic-fin rays hyaline or with a grey or yellow hue in life; knob on lower jaw symphysis absent (Fig. 10).......................................... S. berak

3b Mouth terminal, tip of upper lip level with tip of lower lip (Fig. 9); caudal-, anal- and pelvic-fin rays orange in life; knob on lower jaw symphysis small (Fig. 11)............................................................... S. turcicus