This species is distinguished from its congeners by having an expansive irregular-pentagonal, translucent flank patch in males and by a strong concavity dorsal to the orbit creating a hump-shaped rise in the dorsal profile that gives the head an appearance of being small and pointed; a much deeper body 34-49% of SL (vs. 12.5-29.7% in E. elongatus and E. rivulatus); differs from E. laterofenestra and E. klunzingeri by possessing a translucent flank patch in males that does not reach the pectoral fin; differs from E. laterofenestra and E. leuciscus by a dorsal flank pigmentation pattern of thin transverse lines vs. round semi-circles and oval shapes (Ref. 84470).