A systematic review of Rhinopetitia Géry (Teleostei, Characiformes, Characidae) with descriptions of four new species and redescription of R. myersi Géry Menezes, Naércio A. Netto-Ferreira, Andre L. Zootaxa 2019 2019-11-18 4700 1 59 86 Menezes & Netto-Ferreira, 2019 Menezes & Netto-Ferreira 2019 [151,448,1209,1236] Actinopterygii Characidae Rhinopetitia Animalia Characiformes 9 68 Chordata species paucirastra sp. nov.   Figs. 10–13, Table 2.     Holotype. MZUSP 124118, female 32.0 mm SL, Brazil, Goiás, Minaçu, right bank tributary of Rio Tocantizinho, Serra da Mesa, 14°08’46”S, 48°02’52”W,  March 2006, O.T. Oyakawa& K.C. Mautari.    Paratypes. Allfrom Brazil, Goiás.  INPA 59017, 4(28.0–30.0 mm SL),  MNRJ 51533, 4(30.0–33.0 mm SL),  MPEG 38601, 4(30.0–32.0 mm SL),  MZUSP 95063, 44(25.0–39.0 mm SL, 5 C&S, 29.0–39.0 mm SL),  UFRGS 27590, 4(30.0–33.0 mm SL), collected with the holotype;  MZUSP 77477, 1 male(31.0 mm SL), upstream of ponte do Rubão, Serra da Mesa, about 13°50’S, 48°18’W,  November 1996, D.F. Moraes, A. Akama& O.T. Oyakawa.   Diagnosis.  Rhinopetitia paucirastracan be distinguished from its congeners by having fewer gill rakers on the external part of first gill arch (8–12, vs13–19) and the outer row premaxillary teeth with 3 cusps vs4 to 5 ( Figs. 3and 11). Aditionally it has the body deeper than  R.oligolepisand  R. nigrofasciata(body depth 27.0–31.8 % of SL vs19.2–24.0% of SL and 20.0–24.8 of SL respectively, Fig. 4, Tables 3–5).   Description.Morphometrics of holotypeand paratypesin Table 2. Body small (largest examined specimen 39.0 mm SL). Head and body elongate and laterally compressed; greatest body depth at dorsal-fin origin. Profile distinctly convex from upper jaw to posterior nostril, slightly convex from latter point to dorsal-fin origin, straight along dorsal-fin base, nearly straight to slightly concave from latter point to adipose-fin origin, and concave from latter point to anteriormost dorsal procurrent ray. Ventral body profile convex from tip of lower jaw to isthmus, nearly straight from that point to vertical through pectoral-fin origin, convex from latter point to pelvic-fin origin, and straight from that point to anal-fin origin. Ventral profile along anal-fin base straight and concave on caudal peduncle. Mouth sub-terminal to nearly inferior; lower jaw short, included in upper jaw when mouth closed. Posterior tip of maxilla reaching vertical through anterior border of pupil. Outer premaxillary tooth row with 4 (11), 5 (42*), or 6 (14) teeth, each with three cuspidate teeth, inner row with 4 (67) three to five (5) cuspidate teeth ( Fig. 11). Maxillary ( Fig. 11) with 2 (4), 3 (51*), 4 (11), or 5 (1) anterior larger teeth with five cusps (5), smaller posterior teeth with 3 to 4 cusps (5). Dentary ( Fig. 11) with 4 (67*) anterior large five cuspidate (5), followed by 2 (2), 3 (13), 4 (36*), 5 (15) or 6 (1), 3 to 5 five cuspidate teeth (5), gradually decreasing in size posteriorly. First gill arch with external and internal rows of gill rakers; external row with 8 (2), 9 (16), 10 (22), 11 (16*), or 12 (10) gill rakers. Branchiostegal rays 4 (5), 3 originating on anterior and 1 on posterior ceratohyal.   FIGURE 10.  Rhinopetitia paucirastra, new species, MZUSP 124118, holotype, female, 32.0 mm SL, Brazil, Goiás, Minaçu, Serra da Mesa, Rio Tocantins.   TABLE 2.Morphometric data for  Rhinopetitia paucirastra. Values for the holotype included in the range of female specimens. Standard length in mm; SD = Standard Deviation.    Holotype Males Females  pvalue  Characters n range mean SD n range mean SD  Standard length 32.0 10 24.0–32.0 28.1 2.6 57 25.0–39.0 30.0 2.8   Percentages of SL  Depth at dorsal-fin origin 29.0 10 27.0–30.0 28.7 1.1 57 27.0–31.8 29.4 1.2 0.600  Snout to dorsal-fin origin 55.6 10 53.3–59.0 55.2 1.5 57 53.3–59.3 55.8 1.4 0.423  Snout to pectoral-fin origin 22.8 10 22.4–25.0 24.0 0.8 57 22.1–25.8 23.6 0.7 0.604  Snout to pelvic-fin origin 46.8 10 45.4–48.0 46.8 0.9 57 44.6–48.7 47.1 1.0 0.202  Snout to anal-fin origin 63.4 10 62.5–67.0 63.8 1.1 57 61.8–66.8 64.3 1.2 0.256  Caudal peduncle depth 11.2 10 10.3–12.0 11.2 0.6 57 10.3–13.0 11.3 0.5 0.282  Caudal peduncle length 14.0 10 14.6–15.2 14.9 0.3 57 13.6–16.5 14.8 0.7 0.337  Pectoral-fin length 22.5 10 21.8–24.0 22.6 0.6 56 20.7–24.0 22.6 0.8 0.510  Pelvic-fin length 15.6 10 14.6–17.0 15.6 0.7 57 13.8–17.0 15.7 0.7 0.102  Dorsal-fin base length 12.5 10 10.4–13.0 11.6 0.8 57 10.3–13.0 11.7 0.6 0.101  Dorsal-fin height 25.0 10 23.3–26.0 24.8 0.8 57 23.1–27.0 25.0 0.7 0.240  Anal-fin base length 24.3 10 23.2–26.0 24.4 0.8 57 22.5–27.0 24.4 0.9 0.088  Anal-fin lobe length 17.5 10 16.1–20.0 18.0 1.3 56 16.0–20.0 18.8 0.4 0.874  Eye to dorsal-fin origin 42.8 10 40.0–43.0 41.5 1.0 57 40.0–43.0 42.5 0.7 1.298  Dorsal-fin origin to caudal-fin 50.0 10 48.0–52.0 49.0 1.1 57 45.5–53.0 50.0 1.6 0.396  base Bony head length 25.0 10 24.0–26.0 24.8 0.5 57 23.2–26.0 24.7 0.7 0.228   Percentages of HL  Horizontal eye diameter 40.0 10 39.7–44.0 41.4 1.3 57 37.1–44.0 40.7 1.7 0.319  Snout length 22.5 10 23.3–26.0 24.2 0.8 57 21.8–27.0 24.8 1.3 0.480  Least interorbital width 37.5 10 35.0–39.0 37.1 1.2 57 33.3–40.0 36.9 1.6 0.097  Upper jaw length 37.5 10 36.1–40.0 37.7 1.0 57 35.0–41.0 38.2 1.3 0.419 Scales cycloid. Lateral line complete; perforated scales 33 (6), 34 (23), or 35 (28*). Predorsal scales 11 (30), 12 (33*), 13 (2), or 14 (2). Scale rows between lateral line and dorsal-fin origin 5 (67); rows between lateral line and pelvic-fin origin 4 (67); circumpeduncular scales 12 (53*), or 13 (12). Single series of scales with sinuous posterior borders forming sheath along base of all anal-fin rays. Pectoral-fin rays i,10 (12), 11 (40*), 12 (15). Distal tip of longest pectoral-fin ray not reaching pelvic-fin origin. Pelvic-fin rays i,6,i (67), tip of fin falling short of anal-fin origin. Supraneurals 5 (2), or 6 (3) rod shaped, or with discrete enlargement of dorsal portion; last supraneural located anterior to spines of 9 th(2) or 10 th(3) vertebral centra. Dorsal-fin rays ii,7, i, (67) First dorsal-fin pterygiophore inserting behind neural spines of 11 thvertebral centra (5). Distal margin of extended dorsal fin straight to slightly convex. Dorsal-fin origin closer to caudal-fin base than to snout tip. Base of last dorsal-fin ray situated slightly anterior to vertical through anal-fin origin. Anal-fin rays iv–v,15 (11), 16 (36), 17 (18*), or 19 (1), posteriormost ray adnate. Anal fin with short, inconspicuous, anterior lobe including last unbranched ray plus first 6–7 branched rays. Distal margin of anal fin slightly concave. First anal-fin pterygiophore inserting behind haemal arch of centra 16 th(3), or 17 th(2). Adipose fin present. Principal caudal-fin rays 10/9, (67). Dorsal and ventral procurrent rays 9 (2), 10 (2), 11 (1), or 8 (1), 9(3) and 10(1) respectively. Vertebrae 34 (4), and 35 (1).   FIGURE 11.  Rhinopetitia paucirastra, MZUSP 95063, 30.0 mm SL C&S, jaws and dentition, lateral view, left side, anterior at left.  Color in alcohol.Ground color pale to yellowish brown. Small dark chromatophores around mouth extends laterally to tip of maxilla and up toward top of head and back until the supraoccipital spine, less evident on top of fontanel; slightly larger dark chromatophores on upper portion of preopercle and fourth, five and sixth infraorbital bones and upper and median portions of opercle; lower part of opercle with scattered dark chromatophores. Small dark chromatophores all over upper part of body above lateral line scattered on lower part of body below lateral line. Mid-dorsal and adjacent longitudinal scale rows densely pigmented with small dark chromatophores distributed over whole scales, but leaving an unpigmented area near the border of each scale. Mid-line of predorsal scales with larger chromatophores. An inconspicuous dark mid-lateral stripe in freshly preserved specimens from about vertical line through dorsal-fin origin to caudal base somewhat enlarged over caudal peduncle. A vertically elongate dark humeral blotch occupying 5 longitudinal scale rows vertically and becoming narrower downward. All fins hyaline with scattered dark chromatophores on dorsal, caudal, and anal fins and very few on pectorals, and pelvic fins.   FIGURE 12.  Rhinopetitia paucirastra, MZUSP 95063, 30.0 mm SL C&S sexually mature male; anal-fin rays, lateral view, left side, showing anal-fin hooks.  Sexual dimorphism.Anal fin of sexually mature males ( Fig. 12) with bilateral hooks on fourth largest unbranched ray and first four branched rays. Pelvic fins of sexually mature males with hooks on third to fifth branched rays ( Fig. 13).   Etymology.The species name  paucirastrais from the Latin paucus, meaning few, rastrummeaning raker in allusion to the reduced number of gill rakers on the anterior external portion of first gill arch in comparison with the other species of the genus.   Distribution.This species is known from small tributaries draining into Rio Tocantinsmany of which disappeared during the construction of the Serra da Mesa dam in the upper Rio Tocantins, Goiás, Brazil( Fig. 9). 2452381603 2006-03 MZUSP da Mesa & O. T. Oyakawa & K. C. Mautari. Brazil Minacu -14.146111 Serra da Mesa 21 -48.04778 Rio Tocantizinho 9 68 MZUSP 124118 1 Goias holotype 2452381607 [199,591,1389,1415] Brazil All 9 68 1 Goias paratype 2452381627 [602,1004,1388,1415] INPA Brazil 9 68 INPA 59017, 4 1 Goias paratype 2452381587 [1017,1431,1388,1415] MNRJ Brazil 9 68 MNRJ 51533, 4 1 Goias paratype 2452381623 [151,567,1425,1451] MPEG Brazil 9 68 MPEG 38601, 4 1 Goias paratype 2452381586 [579,1333,1424,1451] MZUSP Brazil 9 68 MZUSP 95063, 44 1 Goias paratype 2452381626 UFRGS Brazil 9 68 UFRGS 27590, 4 1 Goias holotype 2452381633 1996-11 MZUSP Moraes & A. Akama & O. T. Oyakawa Brazil -13.833333 Serra da Mesa 1289 -48.3 Rubao 9 68 MZUSP 77477 1 1 Goias paratype