Tetragonopterus anostomus Silva & Benine 2011

This species is distinguished from all its congeners by having the following characters: a subsuperior mouth (vs. terminal mouth); differs from all congeners except T. araguaiensis by having 17-19 gill rakers on the lower limb of the first gill arch (vs. 11-14); differs from its congeners, except T. denticulatus, T. juruena, T. kuluene by bearing 5-6 principal teeth on dentary (vs. 4) and thinner and sharper teeth on dentary (vs. large and more robust teeth); differs from T. ommatus by having 2-4 teeth on maxilla (vs. 7-8) and with a mark centered on the caudal peduncle (vs. mark limited to the posterior portion of the peduncle); differs from T. carvalhoi by the presence of a rounded mark on the caudal peduncle (vs. a lozenge-shaped mark); differs from T. rarus by the absence of longitudinal dark stripes on the flank (vs. the presence of stripes); differs from T. rarus, T. georgiae by having 3.5 longitudinal scale rows between lateral line and pelvic-fin origin (vs. 4.5-5.5); differs from T. argenteus by having 8 predorsal scales (vs. 11-17) (Ref. 124043).

Dorsal soft rays (total): 9; Analsoft rays: 26 - 30