Tetragonopterus ommatus

This species is distinguished from all its congeners by the number of maxillary teeth 7-8 (vs. 1-6) and the dark, vertically-oriented patch of dark pigmentation limited to the posterior portion of the caudal peduncle (vs. mark centered on the caudal peduncle); differs from T. anostomus, T. denticulatus, T. kuluene by the principal teeth on dentary 4 (vs. 5-6) and by having more robust dentary teeth (vs. thinner and sharper teeth); differs from T. anostomus by having a terminal mouth (vs. subsuperior mouth) and by having two conspicuous humeral marks (vs. only one humeral mark); differs from T. anostomus, T. araguaiensis by the number of gill rakers on the of the first gill arch lower (13-15) and upper (8-9) limbs (vs. 17-20 and 10-12, respectively); differs from T. argenteus by the predorsal scales 8 (vs. 11-17); differs from T. carvalhoi by having a rounded dark mark on the caudal peduncle (vs. a lozenge-shaped dark mark); differs from T. rarus, T. georgiae by the scale rows between lateral line and pelvic-fin origin 3.5 (vs. 4.5-5.5); differs from T. rarus by the absence of dark longitudinal stripes on the trunk (vs. presence of stripes) (Ref. 124043).

Dorsal soft rays (total): 9; Analsoft rays: 25 - 26; Vertebrae: 30