Hemigrammocapoeta menderesensis can be diagnosed from all its congeners in Anatolia by the following unique combination of characters (none unique to the species): mouth small, subterminal, horseshoe shaped, arched and without barbel; lips developed, lower lip with two lateral lobes and median pad; lateral lobe small and shorter than half width of median pad; lower and upper lips with numerous papillae; 6–17 lateral line scales (mean=10.1; SD=0.74) and 36–41 +1–2 scales in lateral series (mean=38.5; SD=0.45); gill rakers on outer side of first gill arch 15–17 (mean=16; SD= 0.24); caudal fin slightly forked, lobes slightly pointed; some flank scales with large black spots and numerous small black dots on each flank scale (Ref. 115535).