Tetragonopterus araguaiensis Silva, Melo, Oliveira & Benine 2013

Tetragonopterus araguaiensis Silva, Melo, Oliveira & Benine, 2013

Fig. 10

Tetragonopterus araguaiensis Silva, Melo, Oliveira & Benine, 2013: 1613 –1631 (original description; type locality: “Brazil, Goiás, Aruanã, Rio Araguaia, Amazon basin).

Diagnosis. Tetragonopterus araguaiensis is distinguished from all congeners except T. anostomus by having 18–20 gill rakers on the lower limb and 10–12 gill rakers in the upper limb of the first gill arch (vs. 12–14 and 8–10).

Tetragonopterus araguaiensis differs from T. anostomus by having a terminal mouth (vs. subsuperior mouth) and by having two conspicuous humeral marks (vs. only one conspicuous humeral mark). It differs from T. anostomus, T. kuluene, T. juruena and T. denticulatus by the presence of 4 principal dentary teeth (vs. 5–6) and also by having larger and more robust teeth (vs. thinner and sharper teeth). Tetragonopterus araguaiensis differs from T. argenteus by having 7–9 predorsal scales (vs. 11–17); it differs from T. carvalhoi by having a rounded mark on caudal peduncle (vs. a lozenge-shaped mark); it differs from T. ommatus by having 0–2 teeth on the maxilla (vs. 7–8 teeth) and by having a centered mark on the caudal peduncle (vs. mark limited to the posterior portion of the caudal peduncle). Tetragonopterus araguaiensis differs from T. rarus and T. georgiae by the presence of 3.5 scale rows between lateral line and pelvic-fin origin (vs. 4.5–5.5). Finally, T. araguaiensis differs from T. rarus by the absence of longitudinal dark stripes on the trunk (vs. presence of stripes).

Description. A detailed description of Tetragonopterus araguaiensis was recently provided by Silva et al. (2013).

Distribution. Tetragonopterus araguaiensis is only known from the middle portion of the Rio Araguaia (Fig. 2 b).

Material examined. Brazil. Types: MZUSP 4820, holotype, 51.8 mm SL, Goiás, Aruanã, Araguaia basin, 14°54’27”S 51°04’52”W, H.A. Britski & P.E. Vanzolini, 15–19 Sep 1966. MZUSP 111003, 5 paratypes (1 c&s), 48.4–53.0 mm SL, same data as holotype. LBP 4154, 1 paratype, 62.5 mm SL, Goiás, Aragarças, Rio Araguaia, 15°53’35.2”S 52°15’00”W, C. Oliveira et al., 10 Dec 2002. LBP 7756, 2 paratypes (one c&s), 32.8–35.3 mm SL, Mato Grosso, Cocalinho, Araguaia basin, 14°23’52.3”S 50°59’29.3”W, J. Senhorini et al., 0 8 Sep 2008. MZUSP 17032, 5 paratypes, 48.5–50.5 mm SL, Mato Grosso, Santa Terezinha, Rio Araguaia basin, 10°35’00”S 50°34’00”W, H. Britski, 0 1 Oct 1964. MZUSP 54523, 3 paratypes, 52.0– 54.5 mm SL, Rio Araguaia basin, no further data. NUP 12743, 1 paratype, 52.1 mm SL, Mato Grosso, Cocalinho, Araguaia basin, Lago Varal, 13°00’52”S 50°36’08”W, Nupelia team, 0 3 Nov 2011. Non type: LBP 17276, 1, 69.5 mm SL, Goiás, Britânia, Araguaia basin, Rio Vermelho, 15°10’23.02”S 51°09’27.1”W.