Centromochlus ferrarisi can be diagnosed from all species of Centromochlinae, with the exception of C. meridionalis by having dorsal and lateral surfaces of head and body darkly mottled with many small rounded blotches, blotches closely spaced, often coalescent and rather poorly delimited on a pale background (v. dorsolateral surfaces either uniformly dusky or dark, with pale blotches on a darker background, or with a few large dark

blotches or spots well spaced and well defined on a pale background). It can be distinguished from C. meridionalis by having the dorsal-fin spine with serrations anteriorly and smooth posteriorly (v. dorsal-fin spine smooth anteriorly and with serrations

posteriorly), seven branched anal-fin rays of mature males (v. six) and posterior nuchal

plate short, not extended anteroventrally (v. posterior nuchal plate with anteroventral

extension). It further differs from C. altae, C. existimatus, C. heckelii, C. meridionalis, C. perugiae, C. reticulatus and C. romani by possessing seven branched anal-fin rays (v. five or six); from C. macracanthus and C. schultzi by having short pectoral-fin spine, c. 15% of SL (v. long pectoral-fin spine, 25% of SL); from C. concolor and C. punctatus by its short posterior cleithral process, c. 5% of SL (v. c. 20% of SL); from C. altae, C. existimatus, C. heckelii and C. perugiae by the absence of the anterior nuchal plate (v. presence); from C. romani by having anterior margin of dorsal-fin spine with serrations (v. smooth); from C. simplex by having adipose fin well developed (v. minute) (Ref. 104786).