Rhinopetitia nigrofasciata, Menezes & Netto-Ferreira, 2019

Menezes, Naércio A. & Netto-Ferreira, Andre L., 2019, A systematic review of Rhinopetitia Géry (Teleostei, Characiformes, Characidae) with descriptions of four new species and redescription of R. myersi Géry, Zootaxa 4700 (1), pp. 59-86: 76-80

publication ID

https://doi.org/10.11646/zootaxa.4700.1.3

publication LSID

lsid:zoobank.org:pub:499CD9ED-D11C-4F0E-B0B5-066590C7928E

DOI

http://doi.org/10.5281/zenodo.5587112

persistent identifier

http://treatment.plazi.org/id/CE7DC7FC-84C5-46B9-980F-E8EEAF0EE25E

taxon LSID

lsid:zoobank.org:act:CE7DC7FC-84C5-46B9-980F-E8EEAF0EE25E

treatment provided by

Plazi

scientific name

Rhinopetitia nigrofasciata
status

new species

Rhinopetitia nigrofasciata   , new species

Figs. 18–21 View FIGURE 18 View FIGURE 19 View FIGURE 20 View FIGURE 21 , Table 4 View TABLE 4

Rhinopetitia cf. myersi, Not Géry, 1964   .— Netto-Ferreira et al., 2014 [in part MZUSP 111886; 111901. Comparative material used in the description of R. potamorhachia   ].

Knodus hereresthes   (not Eigenmann, 1908) – Thomaz et al., 2015 [in part, MNRJ 34678; multilocus phylogeny of the Stevardiinae   ]

Holotype. MZUSP 124121 View Materials , female 33.0 mm SL: Brazil, Pará, Altamira, stream on the right bank of Rio Xingu below rapids of Naninduba , 03°06’49”S, 51°37’47”W, O. Oyakawa, J. Birindelli, C. Moreira, A. Akama, L. Sousa & H. Varella, 14 November 2011. GoogleMaps  

Paratypes. All from Brazil, Pará   . MZUSP 111901   , 48 (29.0–35.0 mm SL) collected with holotype GoogleMaps   . INPA 59919 View Materials , 5 View Materials (27.0–31.5 mm SL)   , MNRJ 51535 View Materials , 5 View Materials (30.0–32.0 mm SL)   , MPEG 38603 View Materials , 5 View Materials (29.5–33.5 mm SL)   , MZUSP 111886   , 60 (25.0–40.0 mm SL, 5 C&S 33.0–40.0 mm SL), UFRGS 27592 View Materials , 5 View Materials , (28.0–35.0 mm SL), Altamira, Pajé beach and mouth of stream Panela , Rio Xingu basin, 03°14’12”S, 52°13’21”W, O. Oyakawa, J. Birindelli, C. Moreira, A. Akama, L. Sousa & H. Varella, 14 November 2011 GoogleMaps   ; MZUSP 93241 View Materials , 2 View Materials (23.0–29.0 mm SL), Itaituba on the left bank of Rio Tapajós , 04°16’14”S, 55°58’34”W, L. M. Sousa & J. Birindelli, 07 November 2006 GoogleMaps   . MZUSP 23691 View Materials , 28 View Materials (17.0–25.0 mm SL), Barreirinha, Rio Tapajós , approximately 4°57’S, 57°01”W, Expedição Permanente à Amazônia, 23 November 1970   . MZUSP 93184 View Materials , 8 View Materials (16.0–31.0 mm SL), Itaituba, Rio Tapajós between Itaituba and rapids of Pimental , 04°21’34”S, 56°10’03”W, L.M. Sousa & J. Birindelli GoogleMaps   . MZUSP 93240 View Materials , 9 View Materials (SL 24.0–28.0 mm), Pimental, right bank of Rio Tapajós , 04°34’S, 56°15’39”W, L.M. Sousa & J.L. Birindelli, 11 November 2006 GoogleMaps   . MZUSP 25554 View Materials , 30 View Materials (22.0–35.0 mm SL), Pimental, right bank of Rio Tapajós upstream the headquarters of the Parque Nacional , 4°36’00”S, 56°16’00”W, J.C. Oliveira, 5 January 1979 GoogleMaps   .

Diagnosis. Rhinopetitia nigrofasciata   differs from most congeners (except and R. oligolepis   and R. potamorhachia   ) by the lower body depth (19.1–24.8 % of SL, Fig. 4 View FIGURE 4 , table 4; vs. 25.0–31.1% of SL, in R. myersi   , R. paucirastra   and R. melanohumeralis   —tables 1, 2, and 5, respectively). The new species can be further distinguished from R. myersi   by the presence of more lateral line scales and more circumpeduncular scales (35–39 and 13–14 vs. 32–34, and 12 respectively), from R. paucirastra   by the higher number of gill rakers on the first branchial arch (13–19 vs. 8–12), and from R. melanohumeralis   by the presence of a well-marked longitudinal stripe extending throughout the body, the inconspicuous humeral blotch and the lack of a reticulate pattern on the flanks (vs. longitudinal stripe diffuse, visible only posterior to dorsal-fin origin). The new species is distinguished from R. oligolepis   by the presence of 5 longitudinal scale rows between dorsal-fin origin and lateral line (5 vs. 4), and from R. potamorhachia   by the lower number of teeth cusps on both jaws (3–5 vs. 7–9).

Description. Morphometrics of holotype and paratypes in Table 4 View TABLE 4 . Body small (largest examined specimen 41.0 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 slightly beyond vertical through anterior border of pupil. Outer premaxillary tooth row with 4 (8), 5 (88), 6 (110*), 7 (9) teeth, each with three (1), four (2), or 5 (3) cuspidate teeth, inner row with 4 (215) five (5) cuspidate teeth ( Fig. 19 View FIGURE 19 ). Maxillary ( Fig. 19 View FIGURE 19 ) with 1 (6), 2 (170*), 3 (34), or 4 (5) teeth, anterior larger teeth with five (3) or six (2) cusps, smaller posterior teeth with 3 cusps (5). Dentary ( Fig. 19 View FIGURE 19 ) with 4 (215), anterior large five cuspidate teeth (5), followed by 2 (2) or 3 (3), smaller five cuspidate teeth, gradually decreasing in size posteriorly. First gill arch with external and internal rows of gill rakers; external row with, 13 (2), 14 (22), 15 (63), 16 (62*), 17 (42), 18 (12), or 19 (2) gill rakers. Branchiostegal rays 4 (5); 3 originating on anterior and 1 on posterior ceratohyal.

Scales cycloid. Lateral line complete; perforated scales 35 (23), 36 (70), 37 (95*), 38 (23), or 39 (1). Predorsal scales 11 (48), 12 (157*), or 13 (9). Scale rows between lateral line and dorsal-fin origin 5 (215); rows between lateral line and pelvic-fin origin 3 (56), or 4 (159*); circumpeduncular scales 13 (40), or 14 (170*). Single series of scales with sinuous posterior borders forming sheath along base extending to about 11 th anal-fin ray.

Pectoral-fin rays i,10 (6), 11 (94*), 12 (102), or 13 (6). Distal tip of longest pectoral-fin ray not reaching pelvic-fin origin. Pelvic-fin rays i,6,i (213), or i, 7, (2), tip of fin falling short of anal-fin origin. Supraneurals 4 (2), or 5 (3), rod shaped, or with discrete enlargement of dorsal portion; last supraneural located anterior to neural spines of 11 th (2) or 12 th (3) vertebral centra. Dorsal-fin rays ii,7,i, (215). First dorsal-fin pterygiophore inserting behind neural spine of 11 th centrum (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, 14 (13), 15 (71), 16 (74), 17 (41), 18 (15*), posteriormost ray adnate.Anal fin with short, inconspicuous, anterior lobe including last unbranched ray plus first 5–6 branched rays. Distal margin of anal fin concave.

First anal-fin pterygiophore inserting behind haemal arch of centra 16 th (2) or 17 th (3). Adipose fin present. Principal caudal-fin rays 10/9, (215.) Dorsal and ventral procurrent rays 10 (1), 11 (1), or 12 (3), 10 (3) or 11 (2) respectively. Vertebrae 35 (2), or 36 (3).

Color in alcohol. Ground color pale to yellowish brown. Small dark chromatophores around mouth extends up from tip of snout and back toward top of head until tip of supraoccipital spine and laterally on upper portion of opercle. Few scattered dark chromatophores on fourth, fifth and sixth infraorbital bones. Small dark chromatophores all over upper part of body above lateral line and scattered and smaller below lateral line above anal-fin base, fewer on anterior lower part of body.

A conspicuous dark mid-lateral stripe in freshly preserved specimens sometimes obscured by guanine with a very conspicuous black line of chromatophores, inserted more deeply into musculature. Stripe crossing upper portion of faint dark vertically elongate humeral blotch occupying four longitudinal scale rows vertically becoming narrower downwards. Midlateral stripe becomes wider posteriorly extending to caudal-fin base All fins hyaline with scattered dark chromatophores on dorsal, caudal, and anal fins and very few on pectorals, and pelvic fins.

Sexual dimorphism. Anal fin of sexually mature males ( Fig. 20 View FIGURE 20 ) with bilateral hooks on largest unbranched ray and first five branched rays. Pelvic fins of sexually mature males with hooks on all branched rays ( Fig. 21 View FIGURE 21 ). No hooks on fins of mature females.

Etymology. The specific name nigrofasciata   is from the Latin words “niger” meaning black, dark and “fascia” meaning band, is in reference to the dark midlateral stripe along the sides of the body of this species.

Distribution. This species is so far known from small streams tributaries of the rivers Tapajós and Xingu, Pará, Brazil ( Fig. 9 View FIGURE 9 ).

MZUSP

Museu de Zoologia da Universidade de Sao Paulo

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Characiformes

Family

Characidae

Genus

Rhinopetitia

Loc

Rhinopetitia nigrofasciata

Menezes, Naércio A. & Netto-Ferreira, Andre L. 2019
2019
Loc

Knodus hereresthes

Thomaz et al. 2015
2015
Loc

Rhinopetitia cf. myersi, Not Géry, 1964

, Not Gery 1964
1964
Loc

Stevardiinae

Gill 1858
1858