Tetragonopterus carvalhoi Melo, Benine, Mariguela & Oliveira, 2011

Silva, Gabriel S. C., Melo, Bruno F., Oliveira, Claudio & Benine, Ricardo C., 2016, Revision of the South American genus Tetragonopterus Cuvier, 1816 (Teleostei: Characidae) with description of four new species, Zootaxa 4200 (1), pp. 1-46 : 26

Tetragonopterus carvalhoi Melo, Benine, Mariguela & Oliveira, 2011

Fig. 7

Tetragonopterus carvalhoi Melo, Benine, Mariguela & Oliveira, 2011: 49 –56 (original description; type locality: Igarapé Iratapuru, Rio Jari, Laranjal do Jari, Amapá, Brazil); Silva & Benine, 2011: 50 –51 (diagnosis); Silva et al., 2013: 1613 –1631 (diagnosis); Araujo & Lucinda, 2014: 309 –315 (diagnosis); Melo et al., 2016: 707 –717 (molecular phylogeny).

Diagnosis. Tetragonopterus carvalhoi is distinguished from congeners by the presence of a lozenge-shaped dark mark on caudal peduncle (vs. a rounded dark mark on caudal peduncle). Tetragonopterus carvalhoi is further distinguished from T. anostomus , T. denticulatus , T. juruena and T. kuluene by the presence of 4 principal teeth in dentary (vs. 5–6) and larger and more robust teeth (vs. thinner and sharper teeth). In addition, T. carvalhoi differs from T. anostomus and T. araguaiensis by the presence of 12–14 gill-rakers on lower limb of the first gill arch (vs. 16–20). Tetragonopterus carvalhoi differs from T. rarus by not having dark longitudinal stripes on the trunk (vs. presence of such stripes) and by having 3.5 scale rows between lateral line and pelvic-fin origin (vs. 4.5–5.5). Tetragonopterus carvalhoi differs from T. anostomus by having terminal mouth (vs. subsuperior mouth), and from T. argenteus by having 7–8 predorsal scales (vs. 11–17). It differs from T. franciscoensis by the presence of 19–22 olfactory lamellae (vs. 11–17). Tetragonopterus carvalhoi differs from T. denticulatus by having humeral marks separated by only one vertical scale row (vs. humeral marks separated by three vertical scale rows). Finally, T. carvalhoi differs from T. ommatus by having 2–4 teeth on the maxilla (vs. 7–8) and by having the dark mark centered on the caudal peduncle (vs. dark mark limited to the posterior portion of caudal peduncle).

Description. A detailed description of Tetragonopterus carvalhoi was recently provided by Melo et al. (2011).

Distribution. Tetragonopterus carvalhoi is apparently endemic from the Rio Jari, Amazon basin, at the Amapá- Pará boundary, northern Brazil ( Fig. 2 b).

Remarks. Tetragonopterus carvalhoi is very similar to Astyanax leopoldi Géry, Planquette and Le Bail (1988) , a species from the Approuague and Oyapock rivers in French Guyana, sharing a overall general appearance and color pattern, including the distinct lozenge-shaped patch of pigmentation on the caudal peduncle. In the original description, Géry et al. (1988) provided an illustration of the infraorbital bones (their figure 6), which clearly shows the presence of a branched laterosensory canal in the sixth infraorbital, a recognized synapomorphy for Tetragonopterus ( Mirande, 2010; Melo et al., 2011). Mirande (2010: 503), however, noted that the autapomorphy “laterosensory canal of the sixth infraorbital branched (his character 76) for T. argenteus is homoplastically present in other characids such as Markiana nigripinnis , Odontostilbe microcephala and Oligosarcus cf. jenynsii . Furthermore, paratypes of A. leopoldi (MHNG 2393.098) bear four supraneurals, whereas Tetragonopterus has only three. Thus, we are convinced that A. leopoldi and T. carvalhoi are distinct taxa and that A. leopoldi should not be considered as a member of Tetragonopterus .

Material examined. Types: Brazil: MZUSP 102268 , holotype, 36.5 mm SL, Amapá, Laranjal do Jari , Rio Jari , Igarapé Iratapuru , 0°33’30”S 52°34’45”W, M. Carvalho, A. Akama, C. Oliveira & F. Marques , 14 Oct 2007. LBP 5306, 6 paratypes, 36.7–42.4 mm SL, Amapá, Laranjal do Jari, Amazon basin, Rio Jari , Igarapé Iratapuru , 0°34’03”S 52°34’41”W, M. Carvalho et al. , 10 Oct 2007. LBP 5376, 16 paratypes, 30.2–42.8 mm SL, Amapá, Laranjal do Jari, Amazon basin, Rio Jari , Igarapé Iratapuru , 0°33’51”S 52°34’45”W, M. Carvalho et al. 14 Oct 2007 . MZUSP 106813, 14 paratypes, 35.8–42.2 mm SL, same data as holotype. Non types: MZUSP 101755, 3 , 56.1–66.0 mm SL, Amapá, Laranjal do Jari, Amazon basin, Rio Jari , 0°38’55”S 52°30’31”W . MZUSP 101803, 2 , 58.5–63.7 mm SL, Amapá, Laranjal do Jari, Amazon basin, Rio Jari , 0°34’16”S 52°34’44”W . MZUSP 102267, 10 , 40.0– 46.3 mm SL, Amapá, Laranjal do Jari, Amazon basin, Rio Jari , 0°34’03”S 52°34’31”W . MZUSP 102268, 18 , 34.9–54.5 mm SL, same data as holotype.

Figures

FIGURE 7. Tetragonopterus carvalhoi. a) MZUSP 102268, holotype, 36.6 mm SL, Brazil, Amapá, Rio Jari, Amazon basin. b) Live specimen from Rio Jari, Amazon basin. Photo (a) from Melo et al. (2011) and (b) by J. L. O. Birindelli.