This species is distinguished from its congeners by the following set of characters: canaliculate scales on the lateral line 43-49 (mean = 45.9; Md = 46; n = 66) ; scales above the lateral line 6-7 (mean = 6.8; Md = 7; n = 66); scales below the lateral line

; 4-5 (mean = 4.4; Md = 4; n = 66); pharyngeal teeth 5/5; body depth low (SL/BD > 4.4; BD/BLD < 2.2); dentary with coronoid process high and narrow. Genetic distances from the other species of Achondrostoma inferred from the mitochondrial cytochrome b gene sequence were: about 7.7% with respect to A. salmantinum; about 6.1% with respect to A. occidentale; about 2.2% with respect to A. oligolepis; 2.7-2.8% with A. arcasii (here defined as the Ebro and Mijares, Turia and Palancia drainages); 2.4% with Central-Eastern Duero and 6.1% with Northwestern Duero. It has 3 autapomorphies, none of them transversions, in the cytochrome b gene (Ref. 128766).