Brachyhypopomus cunia Crampton, de Santana, Waddell & Lovejoy 2017

Brachyhypopomus cunia is distinguished from other species of the genus Brachyhypopomus by the following combination of characters: 16-17 precaudal vertebrae (vs. 18-26 in B. alberti, B. arrayae, B. beebei, B. belindae, B. brevirostris, B. draco, B. flavipomus, B. gauderio, B. hamiltoni, B. janeiroensis, B. jureiae, B. palenque, B. pinnicaudatus, and B. verdii; head depth at eye 47.8-60.0% HL (vs. 36.3-47.7% in B. batesi, B. bombilla, B. provenzanoi, B. regani, and B. sullivani); presence of scales in middorsal region of anterior third of body (vs. absence in B. benjamini; pectoral fin with 10-13 rays (vs. 14-20 in B. bennetti, B. diazi, B. menezesi, and B. occidentalis); mouth width 24.8- 38.0% HL (vs. 15.7-22.6% in B. hendersoni). It has overlapping meristic counts and morphological measurements with B. bullocki and B. walteri, but can be diagnosed by having a very distinctive pigmentation pattern consisting of ventral portions of the flank, over the anal-fin pterygiophores, darkly pigmented, forming a dark stripe along the base of the anal fin (also shared with B. hendersoni), and numerous discrete dark spots (each has a cluster of dark chromatophores) which are scattered over the anal-fin pterygiophores, and in some specimens form an irregular dotted line along the lateral line (vs. absence of dark stripe along the anal-fin base and absence of discrete dark spots over the ventral flank in B. bullocki and B. walteri) (Ref. 116763).

Analsoft rays: 177 - 224

Occurs in floodplain habitats with low conductivity. Occurs sympatrically above the major series of rapids and falls in the lower Madeira with Brachyhypopomus alberti, B. arrayae, B. bombilla, B. brevirostris, B. pinnicaudatus, B. sullivani, and B. walteri; and sympatrically and syntopically below the lower Madeira rapids with B. brevirostris, B. pinnicaudatus, and B. walteri (Ref. 116763). Feeds on aquatic insect larvae and other small aquatic invertebrates (Ref. 116763).