Key to species of Glyptothorax in Iran (expanded from Freyhof et al. 2001 and Mousavi-Sabet et al. 2021)

1a- Adipose length 1.5–3.0 times longer than distance between base of last dorsal ray and adipose origin; 13–17 serrae on pectoral spine, medial pit of thoracic adhesive apparatus with striae........................................ G. steindachneri

1b- Adipose length 0.6–1.2 times of distance between base of last dorsal ray and adipose origin; 5–14 serrae on pectoral spine; medial pit of thoracic adhesive apparatus without striae........................................................ 2

2a- Head and flank with tubercles (rarely absent in some individuals)........................................... G. cous

2b- Head and flank without tubercles, with or without roundish or elongate warts...................................... 3

3a- Upper head, back and flank without brown or black spots or blotches............................................. 4

3b- Upper head, back and flank with few or many, dark-brown spots and, or blotches (potentially faded in poorly preserved individuals).......................................................................................... 5

4a- Outer mandibular barbel not reaching pectoral-fin origin; thoracic adhesive apparatus slightly elevated; medial pit broad, its anterior end roundish; caudal peduncle depth 1.6–2.3 times its length................................. G. sardashtensis

4b- Outer mandibular barbel reaching pectoral-fin origin; thoracic adhesive apparatus strongly elevated; medial pit narrow and spear-blade shaped; caudal peduncle depth 1.1–1.3 times its length....................................... G. pallens

5a- Thoracic adhesive apparatus wider than long, as wide as long in juveniles (0.7 – 0.9 times longer than wide).............. 6

5b- Thoracic adhesive apparatus as wide as long or longer, 1.0–1.6 times longer than wide............................... 7

6a- Thoracic adhesive apparatus moderately elevated with few, short anteromedial striae; caudal-peduncle length 16–20% SL............................................................................................ G. vatandousti

6b- Thoracic adhesive apparatus elevated with many and long anteromedial striae; caudal-peduncle length 13–16% SL................................................................................................ G. kurdistanicus

7a- Anteromedial striae in thoracic adhesive apparatus long and numerous........................................... 8

7b- Anteromedial striae in thoracic adhesive apparatus short or absent............................................... 9

8a- Caudal-peduncle depth 1.3–1.6 times in its length; shortest middle caudal-fin ray 42–49% of longest ray of upper caudal lobe; caudal with pointed lobes; maxillary barbel as long as head (95–108% HL)........................... G. hosseinpanahii

8b- Caudal-peduncle depth 1.6–2.5 times in its length; shortest middle caudal ray 55–65% of longest ray of upper caudal lobe; caudal with rounded lobes; maxillary barbel shorter than head (72–91% HL)............................... G. galaxias

9a- Thoracic adhesive apparatus 1.3–1.6 times as long as wide............................................. G. silviae

9b- Thoracic adhesive apparatus 1.1–1.3 times longer than wide................................ G. alidaeii & G. shapuri