Corresponding author: Gabriel de Souza da Costa e Silva (
Academic editor: Carole Baldwin
The genus
An examination of the fish collections at the Laboratório de Biologia e Genética de Peixes de Botucatu (LBP) and Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Grande do Sul (MCP) revealed the existence of an undescribed
All measurements were taken from point to point to the nearest 0.1 mm using digital calipers (except the postdorsal ridge depth, which was measured using a stereomicroscope and analyzed using the software Axio Vision Release 4.8.2). Counts were taken from the left side when possible. In the description, counts are followed by their frequencies in parentheses. The measurements followed
All examined material was housed at the following Brazilian institutions: LBP (Laboratório de Biologia e Genética de Peixes, Universidade Estadual Paulista Júlio de Mesquita Filho, Botucatu - SP); MCP (Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre - RS); MZUSP (Museu de Zoologia da Universidade de São Paulo, São Paulo - SP); and NUP (Coleção Ictiológica do Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura, Universidade Estadual de Maringá, Maringá - PR).
MZUSP 111956, female, 33.6 mm SL, Brazil, Minas Gerais State, municipality of Santa Bárbara do Tugúrio, Ribeirão Fernandes, a tributary of Rio Pomba, Rio Paraíba do Sul basin,
Brazil, Minas Gerais State, municipality of Santa Bárbara do Tugúrio, Rio Paraíba do Sul basin. LBP 12248, 2 males, 4 females, 1 c&s, 26.6–34.8 mm SL, collected with holotype. NUP 14331, 1 female, 29.6 mm SL, collected with holotype. LBP 1093, 1 male, 33.4 mm SL, Ribeirão Fernandes,
Morphometric and meristic data are given in
Morphometric data for
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33.6 | 26.6–38.8 | 31.0 | 3.0 |
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Predorsal length | 44.2 | 41.5–48.8 | 44.7 | 1.6 |
Preanal length | 59.2 | 56.1–65.9 | 60.5 | 2.4 |
Head length | 31.7 | 28.6–35.5 | 31.8 | 1.5 |
Cleithral width | 32.8 | 30.4–36.9 | 33.5 | 1.8 |
Dorsal-fin unbranched ray length | 21.2 | 20.3–24.1 | 22.2 | 1.1 |
Base of dorsal fin length | 15.4 | 14.3–18.3 | 16.5 | 1.1 |
Thorax length | 18.1 | 15.1–19.6 | 17.0 | 1.3 |
Pectoral-fin unbranched ray length | 20.5 | 20.5–26.0 | 22.6 | 1.5 |
Abdomen length | 27.0 | 22.6–30.1 | 26.2 | 1.6 |
Pelvic-fin unbranched ray length | 22.5 | 17.7–26.6 | 22.9 | 2.1 |
Anal-fin length | 15.3 | 13.7–17.8 | 15.6 | 0.9 |
Ventral unbranched caudal ray | 24.9 | 20.3–30.5 | 25.2 | 2.8 |
Caudal-peduncle depth | 9.0 | 8.3–11.0 | 9.39 | 0.7 |
Postanal length | 34.9 | 31.6–38.1 | 33.9 | 1.4 |
Anal width | 15.4 | 11.3–16.0 | 14.0 | 1.5 |
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Head width | 103.8 | 100.1–108.6 | 103.8 | 2.6 |
Head depth | 61.7 | 53.5–62.8 | 56.9 | 2.3 |
Snout length | 63.1 | 58.0–64.7 | 61.2 | 1.9 |
Interorbital width | 37.7 | 34.8–40.7 | 38.0 | 1.4 |
Orbital diameter | 11.4 | 11.1–15.5 | 12.7 | 1.6 |
Suborbital depth | 39.2 | 35.0–40.5 | 37.3 | 1.6 |
Mandibular ramus | 18.1 | 16.0–23.4 | 19.9 | 1.9 |
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Anal width/cleithral width | 47.1 | 32.0–49.7 | 42.0 | 5.1 |
IO/OD | 29.5 | 21.6–42.1 | 33.5 | 4.5 |
IO/Mandibulary ramus | 50.6 | 44.1–62.5 | 52.4 | 5.6 |
Predorsal length/first ds ray length | 47.9 | 45.7–54.5 | 49.7 | 2.6 |
Postanal length/CP depth | 25.8 | 24.8–31.1 | 27.6 | 1.9 |
Pelvic-fin length/CP depth | 40.0 | 36.0–46.8 | 41.1 | 3.0 |
Ventral unbranched caudal ray/CP depth | 36.2 | 32.1–46.0 | 37.5 | 4.3 |
Postdorsal ridge depth/CP depth | 19.0 | 16.7–26.8 | 21.5 | 3.4 |
Greatest body depth at dorsal-fin origin. Body progressively narrowing posteriorly from cleithrum. Head flat to slightly convex between orbits; superior margin of orbits elevated. Eye small, orbital diameter 11.1–15.5% of HL, situated dorsolaterally just posterior of midpoint of head. Rostral margin of snout with minute, posteriorly-directed odontodes; numerous small odontodes on dorsal portion of head. Opening of swimbladder capsule small. Perforations of compound pterotic distributed on whole bone, greater and more concentrated on its ventral margin; its openings nearly rounded in median region, and irregular along inferior and posterior margins of bone. Lips large; oral disk rounded, papillose; premaxillary teeth 22 (1), 29 (1), 30 (1), 32 (1), 33 (1), 34 (2), 36 (1)*, 37 (2), 38 (1), 39 (2), 40 (2), 42 (2) or 44 (1). Dentary teeth 17 (1), 21 (1), 23 (1), 28 (1), 30 (2), 32 (2)*, 33 (2), 34 (2), 35 (1), 36 (1), 39 (1), or 45 (1). Teeth unicuspid. Maxillary barbel short and free distally.
Dorsal-fin rays ii,7; dorsal-fin originating at vertical through posterior end of pelvic-fin base; distal margin slightly convex. Pectoral-fin rays i,6; distal margin slightly convex; unbranched pectoral-fin ray reaching middle of unbranched pelvic-fin ray; unbranched pectoral-fin ray covered with large and pointed odontodes. Pelvic-fin rays i,5; distal margin of fin slightly convex; tip of adpressed pelvic fin almost reaching anal-fin origin; unbranched pelvic-fin ray covered with conspicuously pointed and well-developed, and uniformly distributed odontodes which are larger at ventral portion. Anal-fin rays i,5; distal margin slightly convex. Caudal fin rays i,7-7,i. Adipose fin absent. Caudal fin truncated with ventral unbranched principal ray longer than dorsal ray.
Body entirely covered by bony plates, except for ventral surface of head, abdomen and region overlaying swimbladder capsule. Dorsal series of plates 24–26, mid-dorsal 17–21, median perforated plates 24–26, mid-ventral 17–22, and ventral 19–22. Trunk with conspicuous, elongated, postdorsal ridge formed by 13–15 raised, unpaired, median plates; ridge continuous posteriorly with procurrent caudal-fin rays. Head lacking crest. Head and body plates covered with minute, uniformly sized and distributed odontodes. Seven pairs of ribs associated with vertebrae 8–14. Ribs slender and poorly ossified. Total vertebrae 29.
Supraorbital sensory canal with four pores; pore s1 located on prenasal plate below nasal plate; pore s3 located on posterior portion of nasal; pore s6+s6 located between frontal plates, on horizontal line through anterior limits of eye; pore s8 located on division between frontals, sphenotic and supraoccipital plates, just above eye. Infraorbital sensory canals with six pores; pore io1 located on anterior portion of first infraorbital; pore io2 located in medial region between first and second infraorbitals; pore io3 located in medial region between second and third infraorbitals; pore io4 located in medial region between third and fourth infraorbitals; pore io5 located in medial region between fourth and fifth infraorbitals and pore io6 located between sixth infraorbital and sphenotic. Preopercular canal with three pores; pore pm2 located on ventral portion of cheek plate, pore pm3 located between cheek plate and preopercle; pore pm4 located between preopercle and compound pterotic. Two postotic pores; pore po2 located just above of branchial slit; pore po3 located in region of overlying opening of swim-bladder capsule.
Two body-coloration patterns observed. First pattern (
Additional coloration pattern of coloration of
Males with a papilla at urogenital opening and fewer teeth in premaxillary 22–39 (
The specific name,
The Rio Paraíba do Sul basin indicating the type locality of
The authors thank Anderson L. Alves, Alex T. Ferreira, José C. Oliveira, Luciana R. Sato, Guilherme J. C. Silva, and Tiago N. A. Pereira for helping with the fish sampling of fishes; Mahmoud Mehanna for help with the etymology; and Edson H. L. Pereira for reading the manuscript and providing valuable suggestions. This research was supported by the Brazilian agencies FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo; proc. 2012/01622-2 to GSCS, and proc. 2010/01610-9 to FFR) and MCT/CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico).